The associations of cancer with types of diets, including vegetarian, fish, and poultry-containing diets, remain unclear. The aim of this study was, therefore, to investigate the association of type of diet with all cancers and 19 site-specific incident cancers in a prospective cohort study and then in a meta-analysis of published prospective cohort studies.A total of 409,110 participants from the UK Biobank study, recruited between 2006 and 2010, were included. The outcomes were incidence of all cancers combined and 19 cancer sites. Associations between the types of diets and cancer were investigated using Cox proportional hazards models. Previously published prospective cohort studies were identified from four databases, and a meta-analysis was conducted using random-effects models.The mean follow-up period was 10.6 years . Compared with meat-eaters, vegetarians (hazard ratio (HR) 0.87 [95% CI: 0.79 to 0.96]) and pescatarians (HR 0.93 [95% CI: 0.87 to 1.00]) had lower overall cancer risk. Vegetarians also had a lower risk of colorectal and prostate cancers compared with meat-eaters. In the meta-analysis, vegetarians (Risk Ratio (RR): 0.90 [0.86 to 0.94]) and pescatarians  had lower risk of overall and colorectal cancer. No associations between the types of diets and prostate, breast, or lung cancers were found.Compared with meat-eaters, vegetarians and pescatarians had a lower risk of overall, colorectal, and prostate cancer. When results were pooled in a meta-analysis, the associations with overall and colorectal cancer persisted, but the results relating to other specific cancer sites were inconclusive.The online version contains supplementary material available at 10.1186/s12916-022-02257-9. Unhealthy diets have been associated with a higher risk of several adverse health outcomes, including cancer , 2. Overn = 686,629 participants) and reported no associations between a vegetarian diet and the risk of breast, colorectal or prostate cancers ) and melanoma  remained significant. The hazard ratios for intermediate models 1, 2 and 3 are presented in Additional file Similar results were found when the models were repeated using the 2-year landmark analysis. In the maximally adjusted models (model 4), the associations for vegetarians were slightly attenuated but remained significant for overall (HR 0.88 [95% CI 0.80 to 0.97]), proximal colon  and prostate  cancer. However, the associations of vegetarian diet with colorectal and colon cancer were no longer significant. Meanwhile, the associations for pescatarians remained significant for overall cancer (HR 0.93 [95% CI 0.87 to 1.00]) and melanoma . There was a lower risk of oesophageal cancer among pescatarians when the 2-year landmark analyses were performed   articles were identified from the search terms. Following the exclusion of duplicates, 1044 abstracts were screened, and 34 manuscripts were reviewed in full. Of these, 25 manuscripts were excluded as they did not meet the inclusion criteria . Additionally, three manuscripts were excluded because they reported the same cohort as a later publication. After adding our UK Biobank study, ten studies in total were included in the meta-analysis , 31–35  for overall cancer , 15, 4 s et al.,  for colo et al.,  for brea et al., , Tantama et al., ) the assFor pescatarian diets, there were 3 studies 1482 events) for overall cancer , 15, 4 s82 eventsok et al ) was remok et al  was remoThis analysis of the UK Biobank cohort suggests that, compared with meat-eaters, vegetarians had a lower risk of all cancers combined and of colorectal  and prostate cancer and that pescatarians had a lower risk of all cancers and melanoma. These associations were independent of major confounding factors, including socio-demographics, lifestyle, multimorbidity and adiposity. When the results were pooled with eight previous studies in a meta-analysis, the associations with overall and colorectal cancers persisted, but the results relating to other specific cancer sites were inconclusive.Although evidence for associations between red and processed meat consumption and increased risk of cancer has been widely reported , 36–39, Regarding specific cancers, in a study including 77,659 participants who were followed up for 7.3 years, Orlich et al. reported that vegetarians had a 22% lower incidence risk of colorectal cancer ) compared with meat-eaters. The reduction in risk was stronger for pescatarians, who had a 43% lower risk of colorectal cancer  . In a reSome of the mechanisms that could explain the associations between vegetarian diet and cancer risk are the presence of bioactive compounds in plant-based diets, such as fibre, phenol, polyphenol, and sulphuric compounds, and other antioxidants compounds, including vitamins. These compounds have been shown to have anti-carcinogenic effects in experimental models and epidemiological studies , 43. On It is important to notice that not all vegetarians’ diets are healthy ; higher Despite low/moderate heterogeneity in our meta-analysis, studies differed in a variety of ways that could lead to inconsistencies in their findings. Some of these include the length of follow-up (ranging from 4.1 to 20.3 years), differences in confounding factors controlled for in each study, differences in sample size across cohorts  and risks of bias attributable to the design of the studies which varied from low to moderate . Studiesn = 20.348), who repeated the assessment centre visit approximately 4 years after recruitment, showed that the dietary touchscreen variables, available for the full cohort, reliably rank participants according to intakes of the main food groups. In our study, we were unable to investigate the association of vegan diet with cancer risk because there were very small numbers (n = 57) of participants who were vegan. Also, we were not able to include energy intake as a covariate as data were available for only half of the cohort population. Moreover, exposure specificity is also a limitation as there was a lack of data on what alternative nutrients or food sources were used to replace meat or fish consumption. An additional limitation of the UK Biobank findings is that data were collected at a single time point resulting in the inability to properly adjust for changes in the exposure or covariates over time.UK Biobank is a large, prospective, general population cohort with data on diet and a wide range of potential confounders and health outcomes. However, the UK Biobank is not representative of the general UK population regarding lifestyle and baseline health . MoreoveFor the meta-analysis, some data limitations should be considered when interpreting the results. The only available evidence was from high-income countries in Europe and North America, i.e. the USA, Canada, the UK and the Netherlands. Therefore, associations between dietary patterns and cancer in other continents and in low-income and middle-income countries remain to be investigated. The number of available studies was generally low for the cancer-specific analyses. This limited the possibility of exploring subgroup analysis, but the heterogeneity across studies was relativity low. The definitions used for different types of diets differed between studies, which could introduce bias and reduce the likelihood of detecting associations. Future research in this area should aim to standardize diet classifications relating to the types of food consumed and their frequency of consumption.Our UK Biobank findings suggest that, compared with meat-eaters, vegetarians had a lower risk of cancer overall, probably due to a lower risk of colorectal and prostate cancer. Pescatarians also had a lower overall risk of cancer, but the relationships with specific contributory cancers were unclear. However, when our risk estimates were pooled with those from previous prospective cohort studies, there was no conclusive evidence in relation to site-specific cancers, even though the associations with overall cancer risk were significant. Larger studies with longer follow-up periods and better classification of diet types are needed to elucidate the benefits, or otherwise, of vegetarian and pescatarian diets on the risk of individual cancers.Additional file 1: Methods. Fig. S1. Flowchart of UK Biobank participants. Table S1. Criteria for the Newcastle-Ottawa Scale regarding star allocation to assess quality of studies. Table S2. Details of dietary characteristics for 175,499 UK Biobank participants with data available for the 24 hrs diet recall. Table S3. Baseline characteristics people with missing data who were not included in the study. Table S4. Association between types of diet and cancer incidence for Models 1-3. Table S5. Landmark sensitivity analysis: Association between types of diet and cancer incidence for all Models after excluding events in the first 2 years of follow-up. Table S6. Characteristics of the cohorts included in systematic review. Table S7. Definitions of vegetarian, lacto-ovo-vegetarian, pescatarian and poultry diets used in the various studies. Table S8. Quality assessment of studies using a modified Newcastle-Ottawa scale for assessing studies in the systematic review of vegetarian diet and cancer risk. Table S9. Risk of bias assessment. Fig. S2. Funnel plot of prospective cohort studies evaluating summary hazard ratios of colorectal, lung, prostate, breast and overall cancer for vegetarians versus meat-eaters. Fig. S3. Funnel plot of prospective cohort studies evaluating summary hazard ratios of colorectal, lung, prostate, breast and overall cancer for pescatarians versus meat-eaters. Fig. S4. Funnel plot of prospective cohort studies evaluating summary hazard ratios of colon and rectum cancer for vegetarian and pescatarians versus meat-eaters. Fig. S5. Funnel plot of prospective cohort studies evaluating summary hazard ratios of breast cancer in premenopausal and postmenopausal for vegetarian and pescatarians versus meat-eaters. Fig S6. Sensitivity analysis of prospective cohort studies evaluating summary risk ratios of of Lacto-Ovo vegetarians defined by Tantamango et al. for overall cancer, Orlish et al. for colorectal cancer, and Penniecook et al for breast cancer, compared with non-vegetarians (reference). Fig S7. Sensitivity analysis of prospective cohort studies evaluating summary risk ratios of overall, colorectal, lung, prostate and breast cancer for vegetarians compared with meat-eaters. Fig S8. Sensitivity analysis of prospective cohort studies evaluating summary risk ratios of breast cancer in premenopausal and postmenopausal women for vegetarians compared with meat-eaters (reference). Fig S9. Sensitivity analysis of prospective cohort studies evaluating summary risk ratios of colorectal, lung, prostate, breast and overall cancer of pescatarians compared with meat-eaters.


Smokers who did not have comorbidities showed a significantly higher overall nmortality risk  than non-smokers among women with breast cancer. Additionally, among women with breast cancer who had a history of smoking, current smokers had a 1.57-fold higher risk  of overall mortality compared with ever smokers. It was shown that a current smoking status is significantly associated with an increase in overall and cancer-specific mortality risk in women with breast cancer. Among women diagnosed with breast cancer, those who quit smoking had a lower mortality risk than current smokers. Our results underscore the importance of smoking cessation for women with BC.The association between smoking status and breast cancer mortality in Asian populations has not been extensively studied. In this study, we aimed to investigate the association between smoking status and mortality risk in women diagnosed with breast cancer between 2011 and 2017 using a real-world population database. Women with breast cancer with a history of smoking had a 1.25-fold higher  risk of overall mortality and a 1.22-fold higher  risk of cancer-specific mortality compared with non-smokers. The stratified analysis also indicated that women with BC who smoked showed a significantly higher overall mortality risk  than women with BC who did not smoke among women without comorbidities. Additionally, current smokers had a 1.57-fold higher risk  of overall mortality compared with ever smokers among women with BC who smoked. It was shown that a current smoking status is significantly associated with an increase in overall and cancer-specific mortality risk in women with BC. Quitting smoking could reduce one’s mortality risk. Our results underscore the importance of smoking cessation for women with BC. Smoking increases the cancer-specific and overall mortality risk in women with breast cancer (BC). However, the effect of smoking cessation remains controversial, and detailed research is lacking in Asia. We aimed to investigate the association between smoking status and mortality in women with BC using the population-based cancer registry. The Taiwan Cancer Registry was used to identify women with BC from 2011 to 2017. A total of 54,614 women with BC were enrolled, including 1687 smokers and 52,927 non-smokers. The outcome, mortality, was identified using Taiwan’s cause-of-death database. The association between smoking status and mortality was estimated using Cox proportional regression. Women with BC who smoked had a 1.25-fold higher (95% C.I.: 1.08–1.45;  In 2020, female breast cancer was the most commonly diagnosed cancer and caused 684,996 deaths worldwide . Its incSmoking is a well-known all-cause mortality risk in the general population, with causes including vascular diseases, respiratory diseases, and cancers ,8, and tAmong women with breast cancer, according to the previous literature, current smokers have approximately 1.5 to 3 times higher all-cause mortality rates and 1.2 to 2 times higher cancer-specific mortality rates when compared to never smokers, and the risk of mortality is positively related to the intensity and duration of smoking ,15,16,17As an important modifiable factor associated with the prognosis of women with breast cancer, smoking habits must be reduced to improve the quality of care and the survival rate of these patients. A detailed characterization of the relationship between smoking and prognosis is vital to encourage smoking cessation when providing education and lifestyle advice to specific groups of women with breast cancer. With this goal in mind, we conducted a population-based, retrospective cohort study to analyze the effect of smoking on mortality risk in women with breast cancer of different ages and with different disease stages, comorbidities, BMIs (body mass indexes), treatment courses, and intensities and durations of smoking habits.The Taiwan Cancer Registry (TCR) was used to identify women with breast cancer. The TCR was established in 1979 to gather information regarding individual demographics, cancer stages, primary cancer sites, tumor histology, and treatment types in patients with cancer to understand the incidence and mortality rates of cancer in Taiwan. Within the registry, the definition of cancer types is based on the International Classification of Diseases for Oncology, third edition (ICD-O-3). The TCR has been used in its short-form and long-form format in different periods to examine different major cancers.The disease comorbidities of women with breast cancer were collected from the National Health Insurance Research database (NHIRD). The NHIRD contains data from Taiwan’s single-payer population insurance system, in which more than 99% of Taiwan’s 23 million citizens are registered. The diagnosis codes in the NHIRD are based on the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). In addition, the death records are based on the database of death registration for the population of Taiwan.The above databases are managed by the Health and Welfare Data Science Center (HWDC) of the Ministry of Health and Welfare. Only researchers can apply to use these databases for research purposes. After verification, the HWDC provides the relevant databases and presents de-identified forms to researchers. The HWDC released the above database to us in a de-identified and anonymized format, and we only used the database provided by the HWDC . This stWomen with new-onset breast cancer (ICD-O-3: C50) from January 2011 to December 2017 were enrolled in this study because TCR started to record the smoking information in 2011. Women with a history of breast cancer before 2011 were excluded. Patients with uncompleted records regarding all of the variables examined were excluded. All of the study subjects were divided into a group of women with breast cancer with a smoking history (current and former smokers) and a group of those without a smoking history (non-smokers). The group with a smoking history included current smokers and former smokers in order to consider the effect of nicotine. According to the guidelines of the Taiwan Cancer Registry, on the date they were initially diagnosed with breast cancer, women were asked by a physician about their smoking status; the presence of smoking, the number of packs smoked per day, and smoking year were determined. The primary outcome in this study was mortality, which was identified using Taiwan’s cause-of-death database. Overall mortality and cancer-specific mortality were both considered in this study to avoid bias when attributing the cause of death. Considering that potential confounding factors may affect the mortality risk in women diagnosed with breast cancer, age, clinical stage, comorbidities, CCI score, treatment types, behavior, and BMI were measured in this study. In Taiwan, at the age of 45, women can receive free breast cancer screening ; therefoCharlson’s comorbidity index (CCI) score is a useful tool to predict mortality risk ,29, and t-test and Pearson’s chi-square test, respectively. The Kaplan–Meier method was used to plot the trend of mortality that the follow up for all of the women started on the date of the diagnosis of breast cancer, and the log-rank test was used to compare the risk of mortality between the two groups. Cox proportional regression analysis was used to estimate the association of the risk of mortality with the hazard ratios (HRs) and 95% confidence intervals (CIs). According to the Schoenfeld residuals test, the assessment of proportional hazard assumption was approved. Multivariable Cox regression was used to present a full model which included smoking status, age, clinical stage, drinking, CCI score, BMI, comorbidities, and treatment types. All analyses were conducted using SAS statistical software version 9.4 . The statistical significance was set at a p-value < 0.05. The Kaplan–Meier curves were plotted using STATA .The differences in continuous variables and categorical variables between the women with breast cancer who smoked and those who did not smoke were evaluated using Student’s In this study, 54,614 women with breast cancer were enrolled, including 1687 women who smoked and 52,927 who did not smoke. The baseline characteristics between smokers and non-smokers among women with breast cancer are presented in p = 0.1552 for overall and p = 0.0473 for cancer-specific mortality).p = 0.0022) risk of overall mortality and a 1.22-fold higher  risk of cancer-specific mortality compared with non-smokers. The stratified analysis of different age groups indicated significant overall and cancer-specific mortality risks in women older than 55, and it was shown that smokers had higher mortality risks than non-smokers. It was also shown that women with breast cancer in late clinical stages (III and IV) who also smoked had significant overall mortality risks compared with non-smokers, but there was only borderline significance regarding the cancer-specific mortality risk. In the current study, we also found that smokers had a 1.43-fold higher risk  of overall mortality than non-smokers in women with breast cancer who drank alcohol. Regarding the CCI score, it was shown that smokers with CCI = 0 had significantly higher overall mortality risks  than non-smokers, but the same estimation was not shown regarding cancer-specific mortality. Smokers with CCI > 3 and those that received chemotherapy also showed significantly higher overall and cancer-specific mortality risks than non-smokers.The overall mortality risk and cancer-specific mortality risk for smokers and non-smokers in women with breast cancer among all of the patients and stratified characteristics are presented in p = 0.0407) of overall mortality compared with ever smokers. Additionally, the stratified analysis of mortality risk between women who quit smoking and those who did not smoke is presented as p = 0.0058), had a CCI = 0 , and received radiotherapy  showed a significantly higher overall mortality risk compared with former smokers. In terms of cancer-specific mortality risk, the estimated mortality risk was as similar to the overall mortality risk. However, women aged 45–54  and 55–64  who currently smoked presented higher risks than women who quit smoking.The comparison between ever smokers and current smokers regarding overall and cancer-specific mortality risks is shown in p53 gene mutations and smoking-related DNA adducts found in smokers’ breast tissue explained the positive association between cigarette smoking and the risk of breast cancer [This large, real-world database study investigated the association between cigarette smoking and mortality risk in women with breast cancer in Asia. Cigarette smoke contains at least 69 known carcinogens, and some of them have been shown to be capable of reaching human breast tissue ,31. p53 t cancer ,33. Furtt cancer ,22. In lt cancer ,17,23,34t cancer ; howevert cancer ,23. The p = 0.34) than in stage 3  breast cancer [In our study, the impact of smoking cessation on the risk of mortality was shown to be more prominent in women in the later stages of breast cancer. This result is slightly different from previous research. A retrospective cohort study in the US showed that smoking cessation was associated with improved survival status amongst breast cancer survivors across all stages, and the strength of this relationship was stronger in stage 1  . A plausThe duration and intensity of cigarette smoking were positively associated with the risk of death in our study. A dose–response relationship was also found in many previous studies. Boone et al. demonstrated that the all-cause mortality risk was significantly higher for women who smoked ≧20 years (HR = 1.47) or ≧35 pack-years (HR = 1.82) in the US , Bérubé The main strengths of this study include the large sample size contributed by Taiwan’s NHIRD, as well as the strong medical records regarding smoking habits and statuses retrieved from the population cancer registry database, instead of a single questionnaire or brief interview, which carry a substantial risk of underreporting ,6,35. AsWe found that ever smokers have a higher risk of overall and breast cancer-specific mortality than never smokers, and former smokers have lower risks of both compared to current smokers. Although the degrees of the benefits on different subgroups vary, there was no disagreement regarding these trends. Our study emphasized the importance of the cessation of smoking in women diagnosed with breast cancer and provided important information for clinicians when giving advice regarding lifestyle adjustment.


Non-steroidal anti-inflammatory drugs (NSAIDs) are a group of commonly used drugs which target inflammation. Because inflammation is a critical component in cancer development, NSAID was proposed to reduce the risk of breast cancer by some studies. However, the results are inconsistent between studies. Moreover, there are insufficient data regarding risk of breast cancer with different characteristics, for example cancer subtype and stage, and few studies have investigated whether the risk will differ by breast density or previous breast disorders. Therefore, we investigated the association between use of NSAIDs and risk of breast cancer using data on NSAID use and breast cancer diagnosis from women in Sweden in general and women from a breast cancer screening program. Overall, we did not have strong evidence to support an association between the use of NSAIDs and the risk of breast cancer. More studies in diverse demographic and geographical settings are needed to confirm our findings.p for interaction: <0.001). In the analysis of Karma participants, the exclusive use of non-aspirin NSAIDs was associated with a lower risk of breast cancer among women with a breast dense area of >40 cm2 . However, the possibility of finding this by chance cannot be ruled out. Overall, we did not find strong evidence to support an association between the use of NSAIDs and the risk of breast cancer.A link has been proposed between the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and the risk of breast cancer. There is, however, insufficient data regarding the subtype and stage of breast cancer, and few studies have assessed the interaction between the use of NSAIDs and breast density or previous breast disorders. There is also a lack of data from population-based studies. We first conducted a nested case-control study within the general female population of Sweden, including 56,480 women with newly diagnosed breast cancer during 2006–2015 and five breast cancer-free women per case as controls, to assess the association of NSAID use with the risk of incident breast cancer, focusing on subtype and stage of breast cancer as well as the interaction between NSAID use and previous breast disorders. We then used the Karolinska Mammography Project for Risk Prediction of Breast Cancer (Karma) cohort to assess the interaction between NSAID use and breast density in relation to the risk of breast cancer. Conditional logistic regression was used to estimate the hazard ratio (HR) and a 95% confidence interval (CI) was used for breast cancer in relation to the use of aspirin and non-aspirin NSAIDs. In the nested case-control study of the general population, exclusive use of aspirin was not associated with the risk of breast cancer, whereas exclusive use of non-aspirin NSAIDs was associated with a modestly higher risk of stage 0–2 breast cancer  but a lower risk of stage 3–4 breast cancer . There was also a statistically significant interaction between the exclusive use of NSAIDs and previous breast disorders ( Anti-inflammatory drugs may influence the risk of cancer development due to the important involvement of inflammation in carcinogenesis ,2. NonstExisting meta-analyses ,9,10,11 To address these inconsistencies in the literature, we took advantage of the Swedish National Register data, together with a rich questionnaire and mammographic data from the Karolinska Mammography Project for Risk Prediction of Breast Cancer (Karma) cohort, to examine (1) whether NSAID use, either aspirin or non-aspirin, reduces the risk of breast cancer, (2) whether the association differs by stage and molecular subtype of breast cancer, and (3) whether breast density and a history of breast disorders modifies the association, using a nested case-control design.In the first analysis, we used data from multiple national registers in Sweden, including the Total Population Register , the CanTo study the interaction between NSAID use and breast density in relation to the risk of breast cancer, we performed a second analysis using the Karma cohort, which includes 70,872 women who attended a national mammographic screening program (between ages 40 and 74) or clinical mammography between January 2011 and March 2013 at any of the four mammography units in Sweden . In thisDue to the large sample size and time-varying nature of exposure  and covariates , we designed a nested case-control study within the cohort of the general female population. We first identified cases of all women with an incident breast cancer diagnosed during the follow-up. For each case, we randomly selected five controls who were free from breast cancer at the diagnosis date of the case (index date), matched to the case on birth year, through incidence density sampling  Figure . In the Through the Prescribed Drug Register, we identified the use of any NSAIDs  between 1 July 2005 and 180 days before the index date to avoid reverse causation, as a previous study  suggesteIn the nested case-control study of the general female population, we identified from the Cancer Register the stage of breast cancer diagnosis based on T, N, and M stages, using the 7th edition of AJCC anatomic stage groups . We alsoVia linkage with the Longitudinal Integrated Database for Health Insurance and Labour Market Studies (Swedish acronym LISA), we extracted information on education and disposable income . Breast 2) of the left and right mammograms, mediolateral oblique (MLO) view. We imputed the missing values of dense area  using lifestyle and reproductive factors, including age, BMI, physical activity, smoking status, alcohol consumption, number of childbirths, age at first childbirth, age at menarche, and postmenopausal status, based on data among all participants of the Karma cohort . We then classified breast density into low (<9 cm2), medium (9–40 cm2), and high (>40 cm2) dense areas, according to the first and third quartiles of the entire Karma distribution. All information, including demographic, reproductive, psychosocial, and lifestyle factors, were collected through a comprehensive questionnaire at enrollment to Karma.Given that the risk of breast cancer is likely not associated with the change in breast density but rather the baseline breast density , we consWe first described the characteristics of cases and controls included in the analyses of the general female population and Karma participants. We then used conditional logistic regression to assess the risk of breast cancer in relation to the use of aspirin and non-aspirin NSAIDs, both exclusively and non-exclusively. Under a nested case-control design, the odds ratio estimated by conditional logistic regression can be interpreted as the hazard ratio (HR) in the underlying cohort, from which cases and controls were drawn . We alsoDifferent covariates were adjusted according to data availability. In the analysis of the general female population, the match-set identifier was used as a stratum. We adjusted for demographic factors in model 1 and further adjusted for CCI, potential indications of NSAID use, number of children, and age at first childbirth in model 2. We additionally adjusted for smoking, BMI, and the use of hormonal contraceptives in model 3 among a subgroup (44%) of women with available data. In the analysis of Karma participants, we also used the match-set identifier as a stratification variable and adjusted for demographic and lifestyle factors in model 1, further adjusted for potential indications of NSAID use in model 2, and additionally adjusted for reproductive factors and CCI in model 3.In the analysis of the general female population, we studied the heterogeneity by stages and molecular subtypes of breast cancer by fitting a separate conditional logistic model for cases diagnosed with each stage or subtype and their matched controls as a competing risk analysis using a cause-specific hazard approach. We also stratified the analysis by the presence of a previous benign breast disorder in the analysis of the general female population and by mammographic density at enrollment in the analysis of Karma participants. We further tested the statistical significance of the interactions between breast disorders/density and NSAID use in an interaction model using Wald tests.We identified 56,480 cases and 282,400 matched controls in the nested case-control study of the general female population. Cases and controls had a comparable distribution of region of birth, educational attainment, and disposable income per consumption unit . Cases aIn the analysis of the general female population, the use of aspirin, exclusively or not, was not associated with the risk of breast cancer in the fully adjusted model , although recent nonexclusive use of aspirin was borderline associated with a lower risk of breast cancer  . The useIn the analysis of the general female population, the clinical characteristics of breast cancer among cases diagnosed since 2008 are shown in 2) in the fully adjusted model  (p = 0.06). In the analysis of the general female population, no statistically significant association was noted between the exclusive use of NSAIDs and the risk of breast cancer, regardless of previous breast disorders (p < 0.001).In the analysis of Karma participants, the exclusive use of non-aspirin NSAIDs alone was associated with a lower risk of breast cancer  among women with high-density breasts (average dense area >40 cmmodel 3) . The intisorders . There wIn this study, which assessed the risk of breast cancer in relation to the use of NSAIDs, we did not find evidence of an association between aspirin use and the risk of breast cancer. However, we detected a slightly higher risk of stage 0–2 breast cancer, but a lower risk of stage 3–4 breast cancer in relation to the use of non-aspirin NSAIDs. The latter was mainly observed among women with high breast density.Our finding on a null association between aspirin use and the risk of breast cancer is coherent between the analyses of the general Swedish female population and Karma participants, after adjusting for different potential confounders. This is also consistent with results from the only existing randomized clinical trial with a median follow-up of 10 years  or 18 yeWe observed a slightly increased risk of early-stage breast cancer in relation to non-aspirin NSAID use. In contrast, non-aspirin NSAIDs were found to be associated with a lower risk of high-stage breast cancer and any breast cancer among women with high breast density. This appears at odds with a previous study reporting a slightly increased risk of breast cancer, especially nonlocalized tumors, among users of non-aspirin NSAIDs  . To the The strengths of this study include the large-scale population-based design for the analysis of the general Swedish female population and rich information about prescribed medications, cancer characteristics, and previous diagnoses, which enabled us to study the exclusive or non-exclusive use of prescribed aspirin and non-aspirin NSAIDs. An additional strength is the large sample size and rich data on breast density and other known risk factors of breast cancer in the Karma cohort.A few limitations should be noted. First, the Prescribed Drug Register did not include medications purchased over the counter (OTC) or used in hospitals or nursing homes. Although ibuprofen is among the top-selling OTC drugs , it is sThis study uses nationwide register-based and self-reported data from the entire female population and a mammographic screening cohort in Sweden and provides further evidence on the association between the use of NSAIDs and the risk of breast cancer by the stage and molecular subtype of cancer, breast density, and benign breast disorder.In conclusion, we did not find strong evidence to support an association between the use of NSAIDs and the risk of breast cancer.


Black women in the United Kingdom are more likely than White women to be diagnosed with advanced breast cancer and have lower survival rates. We consulted women of Black Caribbean and Black African descent in the United Kingdom on how the Promoting Early Presentation (PEP) booklet and intervention could be adapted for Black women to promote early presentation with breast cancer symptoms.Focus groups with 22 women of Black African and Black Caribbean descent, of whom five had been treated for breast cancer. The participants were recruited from a large UK breast cancer charity and community settings. Data were analysed using Framework Analysis.Justify the focus on Black women, Black people do not talk about cancer, Make interventions inclusive and engaging, and Engage Black communities to deliver interventions.Four themes summarised the participants' views on how the booklet and intervention could be adapted: Breast cancer behaviour change interventions need to be more inclusive, illustrate how breast cancer symptoms manifest on black skin, and emphasise that breast cancer is curable to increase awareness and reduce cancer fear. Researchers should involve Black communities in the design and delivery of interventions to address appropriately cultural barriers to early presentation. Participants received a participant information sheet prior to the focus groups informing them that the focus group discussion was audio‐recorded and their contributions anonymised in the transcription. The focus groups lasted on average 72 min (range: 58 to 90 min) and were facilitated by two of the research team. All focus groups started with a general discussion about how women of Black descent in the United Kingdom should be encouraged to present early with signs of breast cancer, and then participants were asked to make suggestions on how the PEP booklet could be adapted and delivered to Black women. Participants were compensated with vouchers for their travel and time taken to participate in the focus groups.2.4Data were transcribed verbatim, anonymised, and analysed inductively and thematically using Framework Analysis  had a family member or friend diagnosed with breast cancer in the past. Of the 22 participants, 77.3% (n = 17) were over the age of 50 and thus eligible for breast cancer screening and of these 100% had participated in screening. The remaining 22.7% (n = 5) were not eligible as under the age of 50, however one of these (20%) had participated in screening because she was a breast cancer survivor. Most participants  were educated to degree or higher degree level, six participants (27.2%) were educated to O Levels/GCSE/higher education below degree level, and two participants (9.1%) had no formal qualifications. Almost half were in full‐time employment , while a high proportion were retired .A total of 22 women participated in four focus groups, age range 39–77, mean = 57. Five breast cancer survivors were recruited from the “Breast Cancer Voices” panel at the charity Breast Cancer Now, while 17 participants with no personal experience of breast cancer were recruited among employees at the Peabody Trust and the women's group Global Women of Today. Thirteen participants were Black Caribbean, six Black African, and three of mixed descent . Of the 17 participants who did not have personal experience of breast cancer, one had had a previous diagnosis of throat cancer, and more than half Is there a separate protocol for Black women to White women? Are you asking us as individuals here or talking about Black women as a whole? I can only speak for myself. At the start of three of the four focus groups some participants challenged the focus on Black women, not least because the facilitators were White. Some argued that all women are at risk of breast cancer and therefore awareness‐raising campaigns should target women irrespective of ethnic descent:We are all women, but the way that we experience the world – particularly the health system, if we look at it in a historical and social context – is markedly different for White women or women from other ethnic backgrounds so I think it is really good that you are doing this. Black women have the highest mortality rates in the country during childbirth and a lot of that is linked to the structural racism that exists in society, but also in the healthcare profession. A lot of the systems are not designed for Black women in terms of facilitating access and engagement. However, some participants argued that the focus on Black women was justified because of what they perceived as ethnic bias in healthcare:I do not think it has to be targeted at me because I am Black, it has to be targeted at everybody. Make it inclusive […] because you do not want to go through the rigmarole of it's all just happening to Black people. Then it is like a stigma. We are stigmatised again, “only Black people have this.” The breast cancer survivors argued that Black women warrant specific attention in relation to breast cancer as the under‐representation of Black people in cancer materials, cancer patient groups and among healthcare professionals had made them feel isolated during treatment. The participants without a history of cancer agreed that health promotion campaigns generally lack representations of Black women. But while some participants welcomed ethnically inclusive campaigns, others expressed concern that targeted interventions might lead to the stigmatisation of Black communities:3.2.2Some people in the Black community, when it comes to the big C or kidneys or anything else, they do not want anybody to know what is wrong with them. They keep it to themselves. Many participants remarked that in their community “nobody talks about cancer” or mentions the “C‐word”, and that it is common for people to hide their cancer diagnosis even from their closest friends or family:It is this thing about, from my culture, which is Black African, anything that has to do with you not having any of the glands that define you as a woman is almost taboo. You might have a lump and your breast might get taken off … I do not even want to check. I do not want to know. Participants reflected that cultural taboos can make it harder to recognise cancer symptoms, and even lead to the belief that breast cancer does not happen to Black women. The cultural values attached to women's breasts as a symbol of femininity and fertility can dissuade women from practising breast awareness:Although the purpose was to try and make it more inclusive, in terms of people from an African and Caribbean background, it was still a struggle to get enough people of colour on the course. […] When I've been out on the road, I get people … “I do not want to know about that, if I'm going to die I do not want to know about it.” One breast cancer survivor had asked her wider family to disclose cancer diagnoses in the family so that she could know about genetic risks and protect her own two daughters. Another breast cancer survivor had experience as a campaigner to raise cancer awareness among Black communities and had noticed that people of Black Caribbean or Black African descent are reluctant to engage with cancer topics:3.2.3Early detection means best protection should be on the first page to increase appeal and positive tone, while others suggested that case studies and statistics on cancer among Black women would increase engagement:Having statistics and a bit more about Black culture … Because if it is not there, that's how people detach themselves from [leaflets]. While the first theme captured the participants' debate as to whether women of Black Caribbean and Black African descent warrant special attention in relation to breast cancer, the third theme captured their suggestions on how the PEP intervention and interventions in general could be developed to target effectively women of Black Caribbean and Black African descent. The participants suggested changes to the PEP booklet regarding content , inclusivity, and culturally relevant representation , and changes to appearance and layout. Some participants suggested that the slogan I survived breast cancer because I looked after my breasts. It was thought that the booklet should mention the possibility of cancer occurring in young women before they are eligible for breast cancer screening. While some participants did not see the need for cultural adaptation because “a breast is a breast”, others thought it should include representations of how breast cancer symptoms manifest on black skin:There is something that came to mind when I was looking at this from page 3, when it said redness of your breast skin. I was thinking, depending on the colour of skin it might not show redness. How would that work if I am really dark? What would I know when it says redness of your breast skin? The breast cancer survivors argued that the booklet should emphasise that breast cancer is curable and should represent Black women as survivors of breast cancer, and suggested a more engaging title as Going back to even things like the pictures, but everybody on page 6 … There is a “Barbara,” a “Pat,” a “Mary.” [laughter] In my head I am thinking they are all White women. Maybe if we had “Zeinab” … It is silly little things like that, of culture, that you then relate to yourself. Furthermore, it was suggested that the booklet should include names typical of Black women, so that it would resonate with the target audience:3.2.4It's about connecting with activists and people who are doing work on the ground and people that can really connect with certain communities, and it's about building relationships with those people because they are going to bring people. […] The women trust them, particularly if it's in certain communities. So it is about networking, building relationships locally with key people in the community. Regarding how the adapted PEP booklet could be delivered to Black women, the participants stressed the importance of sustainable community engagement as a first step in raising awareness of breast cancer as it would increase trust in the message and uptake of precautionary measures. Some participants also suggested building on existing cancer awareness campaigns aimed at Black women, such as the ‘Black Women Rising’ project led by the breast cancer survivor Leanne Pero:You probably need people like me who have gone through it that they can identify with and that they can think it is okay to talk about it. They need that identifying person so that it is relevant. The suggestions for community engagement went beyond the mere distribution of the PEP booklet or the delivery of the PEP intervention and indicated a need to engage more deeply with Black communities to deliver cancer awareness and education. Some participants who were breast cancer survivors suggested that such campaigns would benefit from people with direct experience of cancer:The participants also suggested social media, for example, Twitter, as channels for raising breast cancer awareness, especially among younger people. Some participants were against the delivery of the intervention in primary care venues because these are usually associated with delivering bad news. Other participants suggested modelling the breast cancer intervention on prostate cancer awareness campaigns targeting Black men, which were familiar to many participants.44.1Promoting Early Presentation (PEP)  and to culturally relevant images and language. The suggestion that more emphasis should be put on Black women as survivors of breast cancer to reduce fear of cancer resonates with past research which found that people of Black African and Black Caribbean descent in the United Kingdom hold more fatalistic beliefs about cancer than White people  were recruited via the charity Breast Cancer Now, which may not be representative of breast cancer charities in the United Kingdom or indeed of Black women's experience of breast cancer. Another study limitation is that we did not recruit participants according to age or to generational status . This may have indicated generational and cultural differences in cancer beliefs or behaviour, like uptake of breast cancer screening, which may have influenced views on how the PEP intervention could be adapted and delivered for different age groups within these two communities. A further limitation is that we recruited participants only in London, and thus our sample is not nationally representative. Although one of the interviewees became part of the project team and co‐author, we did not include PPI or involve any women of Black African or Black Caribbean descent in the earlier design and conduct of the focus groups. Had we done so, we may have minimised the sense of being othered when discussing differences between Black and White women regarding breast cancer outcomes. The relatively high educational status of our sample is also a potential limitation and as such our study may not have captured how other barriers to early presentation  could be addressed through interventions. Last but not least, the standard ethnic categories we used in the demographic questionnaire may not have reflected how participants choose to identify themselves; for example, “Black British” could have been included as a category to minimise the sense of feeling “othered” during the research process.One limitation of this study is that some of the participants who were breast cancer survivors (4.3While further research and community input are needed to design culturally sensitive and inclusive interventions, attention also needs to be paid to the mode and timing of intervention delivery. The current results suggest that women of Black Caribbean or Black African descent would prefer peer‐led interventions or interventions delivered in the community. However, future research should also explore the feasibility and acceptability of delivering breast cancer awareness interventions in healthcare settings, which may have the potential of reaching larger numbers of women.Regarding the inclusion of women of Black Caribbean or Black African descent in breast cancer research, our approach of using snowballing, known contacts, and charities like Breast Cancer Now showed it was feasible to recruit women from these communities, with and without a history of breast cancer. We found it easy to establish trust with the participants once we explained the purpose of our study and the need to address ethnic inequalities in breast cancer. Our participants were keen to share their views and experiences and saw our research as worthwhile. Had recruitment proved to be difficult, we would have reached out to other breast cancer charities and community groups serving the needs of people of Black African and Black Caribbean descent.4.4The participants in our study viewed the PEP intervention positively and largely agreed that culturally tailored interventions would be acceptable for raising awareness of breast cancer among women of Black Caribbean and Black African descent in the United Kingdom. While the PEP booklet provided a vehicle for discussion of wider issues of cancer awareness, beliefs, and cultural barriers around cancer, the focus groups indicated that the original PEP intervention may not be entirely suitable for our target intervention groups. Further research and community involvement are needed to adapt existing interventions like the PEP in a culturally sensitive manner with extensive input from women of Black Caribbean and Black African descent.The authors declare that they have no conflict of interest.


INK4a), and endothelial function . Significant positive correlations were observed between psychosocial measures and inflammatory markers including CRP, IL-6, and ICAM-1. However, no psychosocial scores were related to endothelial function or gene expression of the aging biomarker p16INK4a. Overall, survivors had endothelial dysfunction with reduced EndoPAT ratios. Psychosocial stress is associated with greater inflammation in breast cancer survivors on AIs, corroborating previous studies in cancer-free populations. The lack of association between psychosocial stress and either endothelial function or aging biomarkers could be due to the already low endothelial function and accelerated aging in our cohort of breast cancer survivors on AIs, though our small sample size limits conclusions. Further work in a larger and more diverse cohort of patients is needed to further understand the relationships among inflammation, aging and endothelial function in breast cancer survivors.The use of aromatase inhibitors (AIs) is associated with higher rates of cardiovascular events and lower endothelial function in breast cancer survivors. Psychosocial stress is associated with higher levels of inflammatory and aging markers, and lower endothelial function in otherwise healthy subjects. These associations among breast cancer survivors on AIs are not well defined. A cross-sectional study of 30 breast cancer survivors on AIs was performed to assess the associations between self-reported scores of psychosocial measures of depression, anxiety, and stress assessed by validated questionnaires with markers of inflammation , aging (p16 Approximately 1 in 8 women in the U.S. will be diagnosed with breast cancer in their lifetime. Although breast cancer is a leading cause of cancer mortality worldwide, the 5- and 10-year survival rates are 90% and 84%, respectively2. This is due in large part to early detection and improved treatment methods, including extended treatment with aromatase inhibitors (AIs), the primary adjuvant endocrine therapy for breast cancer survivors with estrogen positive tumors3. Although AIs reduce the risk of breast cancer recurrence, extended use of AIs is associated with increased risk of cardiovascular disease events. Aromatase catalyzes the final step in the biosynthesis of estrogen and reduced endogenous estrogen levels leading to a loss of estrogen-mediated protection from endothelial dysfunction and cardiovascular disease in postmenopausal women5. The vascular protective effects of estrogen are mediated via enhanced nitric oxide (NO) signaling6 and anti-inflammatory effects7, among others.Recent evidence suggests adverse changes in vascular function begin to occur almost as soon as AI treatment begins8.Breast cancer (BC) is the world's leading cause of cancer mortality in women9. Indeed, the psychosocial impacts of breast cancer are well recognized, with higher rates of depression and anxiety observed among breast cancer survivors compared to the general female population, even 5 years post-diagnosis11. Depression and other indicators of both acute and chronic stress are associated with increased levels of circulating inflammatory and aging markers as well as changes in endothelial function in otherwise healthy subjects14. However, these associations among breast cancers survivors on extended AI treatments are not well understood.Receiving a breast cancer diagnosis, subsequent treatments and symptom management can be a stressful and life-changing experienceTo address this gap in the literature, the current study evaluated cross-sectional associations among three indicators of psychosocial stress , markers of inflammation and aging, and endothelial function among a cohort of 31 breast cancer survivors on AI recruited to participate in a pilot randomized control trial (RCT) of mindfulness based stress reduction. Analyses reported herein were limited to the baseline data obtained as part of that RCT, prior to the intervention.A cohort of 30 breast cancer survivors on AIs were recruited to participate in a pilot randomized control trial (RCT) of mindfulness-based stress reduction. Individuals with a diagnosis of hormone receptor positive HER2 negative breast cancer who were prescribed an aromatase inhibitor at the University of Minnesota Masonic Cancer Center were eligible. All cases had completed breast cancer treatment and were actively taking an AI. Subjects with a history of tobacco use, myocardial infarction, congestive heart failure, or cardiac catheterization requiring intervention were excluded. Medical record abstraction for cases confirmed diagnosis, stage at diagnosis, use of chemotherapy, use of radiation, and personal medical history including medications (including type of prescribed aromatase inhibitor). Participants completed surveys, laboratory and vascular testing. The protocol was approved by the University of Minnesota Institutional Review Board and the Masonic Cancer Center Review Committee. All methods were performed in accordance with the relevant guidelines and regulations. All patients provided written informed consent according to the Declaration of Helsinki.Potential cases were identified by their treating physician and were then invited to participate in the study between June and August 2020. For those who expressed interest, a screening phone call was placed to discuss the study and identify participants. Failure to answer the phone call or return the phone call was identified as passive refusal to participate in the study. Consented subjects were invited to undergo vascular assessment and biomarker assessment at baseline and completion of the study. Those consented subjects who completed the protocol received one $25 gift card. In total, 43 individuals were screened for the study, 33 met eligibility and enrolled, 30 had evaluable data. Most participants were diagnosed with stage 1  or stage 2  breast cancer, with just 3 participants (10.0%) diagnosed with stage 3. Among the study participants, 13 were on letrozole, 11 on anastrazole, and 6 on exemestane. Median time on AI was 33 months (range 12–76).16. EndoPAT measures the dilatory response through pulsatile volume changes at the fingertips, known as Peripheral Artery Tone (PAT). EndoPAT technology is a non-invasive FDA-approved testing device for the diagnosis of endothelial dysfunction. The EndoPAT examination required the patient to be supine, at rest, in a quiet, air-conditioned room. Subjects were fasting at least 8 h before the study. Subjects were asked not to exercise, use caffeine, high-fat foods, or vitamin C for at least 4–6 h before the test. Low EndoPAT ratios (< 1.6) are indicative of worsening endothelial function and increased CV risk5.Vascular assessment was performed using the EndoPAT 2000 as previously describedAll study assessments were conducted in a specifically designed research space for clinical vascular assessments. Blood collection and vascular functional measurements were conducted in the morning by a trained technician. All testing was completed by the same technician to reduce inter-technician variability. The EndoPAT assessments were performed in triplicate, and the mean  indices were used in statistical analyses.18. ICAM-1 is a cell surface glycoprotein expressed at low basal level in endothelial, epithelial, and immune cells, but is upregulated in response to inflammation19. ICAM-1 has been reliably used as a biomarker for endothelial dysfunction20. Cellular senescence was assessed by measuring the expression of CDKN2A, the gene encoding p16INK4a in CD3 + peripheral blood mononuclear cells (PBMCs) as a surrogate biomarker for human aging22. The Translational Therapy Laboratory (TTL) purified CD3 + PBMCs from bulk PBMCs isolates from whole blood samples. Total RNA was isolated from patient CD3 + PBMCs and CDKN2A/p16INK4a and 18S housekeeping gene expressions were measured by real-time quantitative polymerase chain reaction by TTL staff. Blood samples were collected first, prior to vascular functional assessments. All blood samples were appropriately processed and aliquoted for measurement of respective biomarkers.Biomarkers were obtained using a fasting blood draw to evaluate the following inflammatory markers: C-reactive protein (CRP), interleukin-6 (IL-6), and interleukin-8 (IL-18). Prior research has shown that CRP, IL-6 and IL-18 are three key inflammatory biomarkers associated with inflammation in breast cancer survivors23, PHQ-9 Depression Scale24, Perceived Stress Scale25, and Generalized Anxiety Disorder26. The 4-item CDC Healthy Days measure assesses quality of life by asking about self-reported health  and the number of days in the past month that physical health was poor, mental health was poor, and daily activities were impacted by either poor physical or mental health (3 items)23. The self-administered Patient Health Questionnaire (PHQ)-9 is a validated clinical and research tool to measure depression symptoms and severity24. Item responses range from “0”  to “3” (nearly every day) for a combined scoring of 0–27 measures the degree to which situations in one’s life are appraised as stressful25. The 10 item PSS is suggested for examining the role of nonspecific appraised stress and as an outcome measure of experienced levels of stress, with scores ranging from “0” (never) to “4” (very often). Scores ranging from 0–13, 14–26, 27–40 would be considered low, moderate, or high perceived stress, respectively. The GAD-7 is a clinical measure for assessing generalized anxiety disorder (GAD). The questionnaire consists of seven items that are summed to generate a global score26; cut points of 5, 10, and 15 can be interpreted as representing mild, moderate, and severe levels of anxiety.The following questionnaires were completed by participants at baseline: The 4-item CDC Healthy Days measure evaluating self-reported health and quality of lifeAnalyses reported were limited to the baseline data obtained as part of the RCT, prior to the intervention, and thus represent a cross-sectional evaluation. Descriptive statistics were calculated across all subjects as mean (SD) for continuous variables and count (percentage) for categorical variables. Continuous variables that were highly skewed were log10 transformed before any statistical modeling was performed. One negative EndoPAT measurement was coded as NA and omitted from all analyses. Outcome measurements were assumed to be missing completely at random. All regression models used a complete-case analysis and subjects with a missing value for either the independent or dependent variable were removed. We estimated the mean increase in each inflammatory or senescence marker associated with a one point increase in each psychosocial score  through three independent simple regression models for each inflammatory or senescence marker. We reported point estimates of the associated average increase along with 95% confidence intervals. All significance testing was performed at the 5% level. No adjustments for multiple comparisons were made. All analyses were conducted using R v3.6.1 .The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.The demographic characteristics of study participants (n = 30) are listed in Table 5. Mean scores from the PHQ, GAD, and PSS assessments indicate that subjects had low levels of depression, anxiety, and stress. In our sample, we calculated Cronbach’s alpha values of 0.766 for the PHQ-9, 0.823 for the GAD-7, and 0.841 for the PSS. Values for all measures could not be obtained from all study participants and the number of subjects missing any one of these values is also shown in Table Average EndoPAT ratio, psychosocial stress measure scores, inflammatory biomarker concentrations, and senescence biomarker concentrations for the study population as a whole are displayed in Table ^ = 0.31 ; p = 0.05) and PHQ scores ; p < 0.01) were significantly and positively correlated with higher CRP levels as shown in Fig. ^ = 0.12 ; p = 0.09). Higher PHQ scores were significantly (p < 0.05) associated with increased IL-6 concentrations ; p = 0.02) ; p = 0.21)) and PSS scores ; p = 0.31)) and higher levels of IL-6, neither of these associations were statistically significant. There was no significant association between psychosocial stress scores and IL-18 levels ; p = 0.01), PHQ ; p = 0.01), and PSS ; p = 0.05) scores as seen in Fig. Associations between psychosocial stress scores and endothelial dysfunction are shown in Fig. 21. The Ct (cycle threshold), as shown in Fig. Activation of the CDKN2A gene by tissue damage or cellular stress induces the expression of p16, a common biomarker of cellular senescence28.Our findings in breast cancer patients on AIs demonstrate a significant positive correlation between psychosocial stress scores and several inflammatory markers, corroborating previous studies in cancer-free populations. Nevertheless, in contrast to studies in otherwise healthy subjects, there was no significant association between scores of perceived stress, depression, or anxiety and either endothelial function or aging biomarkers. In this cohort of breast cancer survivors on aromatase inhibitors, endothelial dysfunction was present, consistent with previous reports29. It is estimated that 5 years of an AI compared with no endocrine therapy would reduce breast cancer recurrence by about two-thirds during treatment and by about one-third during years 5–930. Despite their superior efficacy over tamoxifen for hormone-sensitive breast cancer31, aromatase inhibitors may increase the risk of cardiovascular diseases, including hypertension, dyslipidemia, and ischemic heart disease33.Survivorship of breast cancer patients has remarkably improved over the past three decades, thanks to advancements in diagnostics, care models, and therapeutics including aromatase inhibitors (AIs). AIs are the standard treatment for postmenopausal patients with hormone receptor-positive breast cancer as both adjuvant and metastatic treatments9, which creates significant psychosocial stress. The prevalence of depression is highest during the first year after a breast cancer diagnosis, and according to a systematic review, the frequency of depressive symptoms ranges from 9.4 to 66.1%10. Other studies have found a 42% rate of psychiatric disorders in recently treated breast cancer survivors and 35.7% of these women had depression, anxiety, or both11. Additional systematic reviews have suggested a higher prevalence of depression and anxiety among breast cancer survivors when compared to the general female population, even more than 5 years after diagnosis10. Nonetheless, we note that our patient sample had relatively low levels of depressive symptoms, anxiety and perceived stress at the time of their study enrollment. Our participants were, on average on AIs for 33 months suggesting they may have learned to cope well with their diagnosis and concomitant treatment. Additionally, psychosocial stress may be low in these women given that most of them had been diagnosed with early stage breast cancer, with excellent prognoses. Regardless, we did observe positive associations between psychosocial measures and most of our inflammatory biomarkers, suggesting a clear relationship between inflammation and psychosocial functioning.While the prognosis for breast cancer is generally positive, breast cancer survivors are affected by tremendous physical, functional, financial, emotional, and social challenges34. Breast cancer survivors taking AIs are more likely to report sexual problems than those taking tamoxifen35 or not having any endocrine therapy36.Side effects of AIs such as vasomotor complaints, vaginal dryness, and diminished libido may also add to the higher stress levels in breast cancer survivors37. Several studies have previously examined inflammatory markers as predictors of disease recurrence and death in cancer populations. Cancer survivors with persistent inflammation may have an elevated risk of recurrence as a result of the effects of inflammatory processes38. Three key inflammatory biomarkers associated with inflammation in breast cancer survivors are CRP, IL-6, and IL-18. CRP is a nonspecific protein produced by the liver in response to inflammation, infection, and tissue damage. CRP concentrations in women diagnosed with breast cancer are positively associated with death due to any cause, death due to breast cancer, and additional breast cancer events38. The association between IL-6 elevation and increased risk of cancer recurrence is less clear and may only apply to certain breast cancer subtypes such as HER2- tumors39. Studies have shown that breast cancer survivors with elevated IL-18 serum levels have shorter relapse-free survival durations than those with lower IL-18 levels40.Inflammatory pathways contribute to the pathophysiology of both cancer and cardiovascular disease43. Inflammatory cytokines increase to a varying degree following radiation44 and chemotherapy45. Significantly higher IL-6 among depressed cancer patients compared to healthy subjects, and higher levels of inflammatory markers were associated with fatigue and sleep disturbance46. Similarly, higher levels of IL-6 are associated with frailty in older breast cancer survivors47. Several studies have also reported the correlation between inflammatory mediators and measures of psychosocial stress in breast cancer survivors. The inflammatory mediators IL-6 and TNF-alpha were positively correlated with social anxiety and depressive symptoms, respectively in two studies of breast cancer survivors49. In breast cancer survivors one year post-radiotherapy, both depressive symptoms and higher inflammatory markers were independent risk factors of fatigue; however, the correlation between depressive symptoms and inflammatory markers was not statistically significant50. CRP was positively associated with depressive symptoms only among women who reported high levels of cancer-related stress in a longitudinal study of women with breast cancer51. Inflammation was positively correlated with depressive symptoms only in women who also reported high level of anxiety, perceived stress, negative affect, or sleep disturbance52. Counterintuitively, IL-6 was found to negatively correlate with anxiety symptoms in one study49. In agreement with the majority of these studies, in our cohort of breast cancer survivors on AIs, depressive symptoms were significantly and positively correlated with CRP and IL-6 with similar, albeit non-significant patterns of associations noted for anxiety and perceived stress. In contrast, IL-18 was not correlated to psychosocial measures in our study.Higher levels of inflammatory cytokines were reported in the blood of breast cancer survivors by several groups12. Chronic psychosocial stress may induce heightened inflammatory activity through the hypothalamic–pituitary–adrenal axis (HPA) and the autonomic nervous system53. Psychosocial stress has been associated with higher circulating cytokines levels including TNF-alpha and IL-653. In women, high levels of job stress and burnout were associated with high levels of TNF-alpha13 and CRP14. A strong inverse correlation was found between socioeconomic status and levels of circulating CRP, TNF-alpha and IL-655. Loneliness was also associated with higher IL-656. In addition to the observational studies that show a strong association between psychosocial stress and inflammation, experimental studies demonstrate a bidirectional cause-effect relationship between stress and inflammation. Intriguingly, acute laboratory stress paradigms show that stress can cause an inflammatory response58, and inflammation can also provoke depressive symptoms60.Several lines of evidence suggest that the associations between psychosocial stress and inflammation exist in cancer-free subjects as well61. Endothelial dysfunction, which is an independent risk factor for cardiovascular events in the Framingham risk score, precedes and potentially mediates the development of several cardiovascular diseases62. Reactive hyperemia measured non-invasively by EndoPat is a consistent surrogate for endothelial function in clinical studies15. Using the EndoPat technique, we have previously demonstrated reduced endothelial function in postmenopausal breast cancer survivors on an AI in comparison to healthy postmenopausal women5. In the current study, the average EndoPat value in BC survivors on AIs was 0.6 similar to the value reported in our previous study5. The association between psychosocial stress and endothelial dysfunction has not been reported in breast cancer survivors. In the current small cohort of BC survivors on an AI, there was no significant correlation between parameters of psychosocial stress and EndoPat values.Aromatase inhibitors and ionizing radiation have been linked with reduced endothelial function in cancer survivors63. Mental stress induces endothelial dysfunction in healthy subjects64. The lack of association between psychosocial stress and low EndoPat values in the current study may be due to the already low values in a cohort of breast cancer survivors on AIs and/or the small sample size of our study. ICAM-1 is a biomarker for endothelial dysfunction that belongs to a family of adhesion molecules, which are mediators of cellular adhesion between endothelial cells and leukocytes20. ICAM-1 is an independent risk factor for atherosclerosis and developing coronary heart disease65. Higher chronic stress was associated with lower flow-mediated dilation and higher ICAM-166 and higher ICAM-1 was significantly higher in low socioeconomic status subjects67. In the current study, we observed a significant correlation between parameters of psychosocial stress and ICAM-1 in breast cancer survivors on AIs. The positive correlation between stress and ICAM-1 may be predictive of a later-onset decline in endothelial function if the stress continues.Psychosocial stress is associated with impaired endothelial function in several populations, including young adults with major depressive disorder68. In addition to the clinical evidence of premature aging, cancer survivors demonstrate high levels of aging biomarkers, such as p16INK4a a marker of cellular senescence that is encoded by the CDKN2a gene69. In breast cancer patients, chemotherapy significantly increased the expression of p16INK4a, comparable with 10–17 years increase of chronological age71. Anthracycline-based chemotherapy was associated with the largest increase in p16INK4a expression, comparable with 23–26 years of chronological age71. Intriguingly, aging-related functional limitations were reached 5–10 years earlier in breast cancer survivors than cancer-free women72. In the general population, chronic psychosocial stress was associated with increased expression of p16INK4a73. Nevertheless, the association between psychosocial stress and biomarkers of aging has not been specifically reported in breast cancer patients. In our cohort of breast cancer survivors on AIs, there was no significant correlation between psychosocial stress and p16INK4a.Cancer survivors demonstrate clinical signs of premature aging and frailtyThe current study has a number of limitations that warrant discussion. First, the study lacks a comparison group of same-aged women without breast cancer. Therefore, we cannot infer whether the observed associations or the lack thereof is specific to breast cancer survivors on AIs or generalizable to an age-matched cancer-free population. Second, the small sample size may have hindered our ability to detect statistically significant correlations between multiples variables. Finally, our sample was predominantly white, well-educated women; thus, generalizability to other demographic groups could be limited.In conclusion, our findings in breast cancer patients on AIs demonstrate a significant positive correlation between psychosocial stress scores and several inflammatory markers, corroborating previous studies in cancer-free populations. Nevertheless, in contrast to studies in otherwise healthy subjects, there was no significant association between psychosocial stress cores and either endothelial function or aging biomarkers. This observed lack of association may be due to the already low endothelial function and accelerated aging in our cohort of breast cancer survivors on AIs, or due to the small number of patients included in this study. Further work in a larger cohort of patients is needed to confirm or refute this lack of association.Supplementary Table 1.


This study aimed to evaluate the preliminary effectiveness of an educational intervention using a web-app to improve knowledge of breast cancer risk factors and symptoms and adherence to healthy eating and physical activity among women without breast cancer diagnosis in Asturias (Spain).A pragmatic randomized pilot trial was conducted to evaluate the impact of a web-app-based intervention for women without breast cancer diagnosis. Women in the intervention group participated in a 6-month intervention web-app based on the Behaviour Change Wheel Model. The web-app includes information about breast cancer risk factors, early detection, physical activity and diet.p < 0.001) and symptoms + 1.18 (p < 0.001) identified by women in the IG.Two hundred and eighty-fifth women aged 25–50 were invited to join the study. Two hundred and twenty-four were randomly assigned to either the intervention group (IG = 134) or control group (CG = 90) according to their place of residence. Adherence among women in the IG increased significantly from pre- to post-intervention for eight of the 12 healthy behaviors and for the identification of six risk factors and six symptoms compared to women in the CG and, among whom adherence only increased for two behaviors, the identification of one risk factor and 0 symptoms. The intervention significantly improved the mean number of risk factors + 1.06 (The preliminary results of this study suggest that an educational intervention using a web-app and based on the Behaviour Change Wheel model could be useful to improve knowledge of breast cancer risk factors and symptoms and to improve adherence to a healthy diet and physical activity in women without a previous breast cancer diagnosis.The online version contains supplementary material available at 10.1007/s10552-022-01647-x. Breast cancer is one of the most common tumors in women and the most frequent in women under 40 years of age . ApproxiSome risk factors associated with the development of breast cancer, such as age, family history, and age at menarche and menopause, among others, are considered non-modifiable . HoweverAccording to Borgquist et al. , there aThere is growing evidence of the benefits of health promotion interventions for reducing cancer risk among high-risk individuals. It is essential that breast cancer health promotion programs are carried out in a more targeted, individualized way to ensure that they reach women . EducatiThe study’s main aim was to evaluate the preliminary effectiveness of an educational intervention using a web-app to improve knowledge of breast cancer risk factors and symptoms among women without breast cancer diagnosis in the Principado de Asturias (Spain). The secondary aim was the assessment of adherence to healthy eating and physical activity. The present study attempts to demonstrate that an educational intervention using a web-application based on the Behaviour Change Wheel model could be useful for improving knowledge of breast cancer risk factors and symptoms, as well as improving adherence to a healthy diet and physical activity among young women without a previous diagnosis of breast cancer.A pragmatic randomized pilot trial was carried out from November 2019 to November 2020 at the University of Oviedo. The study was registered at ClinicalTrial.gov with number NCT04396665 and approved by the Principado de Asturias Ethics Committee (ref. 147/19). This study is reported following the CONSORT extension for pragmatic pilot trials .Two hundred and eighty-five women aged 25–50 were recruited in December 2019. The selection was made by convenience from a cohort of a previous study. Inclusion criteria were not having a diagnosis of breast cancer, having access to the internet via a fixed or mobile device, and signing an informed consent form to voluntarily join the study.The women were contacted by telephone to request their collaboration. The study objective and phases were explained to them during the telephone call. Those who verbally agreed to participate were sent an email with more detailed information and the informed consent form, which was completed online.n = 148) and Oviedo plus Gijón (n = 112). A number (1 and 2) was assigned to each cluster. Using Excel Aleat Function each number was assigned into the intervention group (IG = Avilés) and the control group (CG = Oviedo plus Gijón). Considering the potential bias and given the impossibility of blinding the intervention for participants, because those that got access to the web-app were able to recognize that they were in the intervention group, we opted for clustering the women to avoid any potential contamination that could result from the women exchanging information due to the proximity of their residences (the distance from Avilés to Oviedo and Gijon is about 35 km).Twenty-five of the women who were contacted by telephone decided not to participate. The remaining 260 were grouped according to their place of residence: Avilés .The women who signed the informed consent form were sent the data collection form by email pre-intervention and again 6 months after the intervention (post-intervention). The form included five sociodemographic questions , the Motiva.Diaf questionnaire , and twoWe used the two dimensions of the MARA questionnaire . Nine riThe Motiva.Diaf questionnaire  was usedWomen in the IG participated in a 6-month intervention (January–June 2020) based on the Behaviour Change Wheel Model  in whichA web-app specifically designed for this study was used. The app was divided into six sections: (i) breast cancer risk factors; (ii) early detection of breast cancer (breast self-examination and signs and symptoms); (iii) physical activity (‘create your own routine’ and related resources); (iv) nutrition; (v) news ; (vi) contests, where women could complete challenges related to nutrition and physical activity.The content of sections (i) and (ii) was permanent from the beginning to the end of the intervention and consisted of texts and images relating to the risk factors and symptoms of breast cancer, as well as six explanatory videos showing the steps required to correctly perform a breast self-examination. Both sections were developed following the advice of a breast cancer nurse practitioner and a medical doctor.Sections (iii) and (iv) included information in the form of texts, images, or videos related to physical activity and nutrition and were updated twice a week. In relation to physical activity, the women were provided with information about different outdoor walking routes in the Principado de Asturias. Throughout the intervention, they could access 58 videos showing a woman performing exercises of varying intensity and difficulty, arranged by body zones, which served as motivation and guidance enabling them to learn and perform them correctly. The videos were accompanied by an exercise plan . These resources were intended to help participants design routines and activity plans to be carried out at home. In the nutrition section, women had access to healthy recipes and videos featuring a nutrition expert who gave them tips and general recommendations for a healthy diet. These were updated every 15 days and the expert was also available for questions about dietary habits via email. Sections iii and iv were developed according to the advice and support from a sports and nutrition technician, respectively.Section (v) consisted of news concerning the topic of the study from the press or social media, which was of interest to the participants by the research team. This section was developed by a nurse and a lecturer and researcher in health promotion.Finally, a contest was created in which participants were encouraged to complete the routines and recipes suggested in sections (iii) and (iv) and take a photograph of a routine while they were doing it or a photograph of a recipe they had prepared displaying a logo designed specifically for the intervention. They were then asked to share the photograph with the other women in the contest section. Each completed challenge gave the participant a score. At the beginning of the intervention, the women were informed that the participant with the highest score at the end of the intervention would receive a prize.The sample size was calculated based on the MARA questionnaire scores. A sample size of 76 participants per group was required to detect an average difference between baseline and post-intervention measurements equal to or greater than 0.5 (SD 1.75) points in the total score of each of the two dimensions of the questionnaire with a two-sided significance level of 5%, a power of 80% and a correlation between the two measurements of 0.81 .Since the percentage of losses was significantly differential between groups and especially important in the intervention group (26.1%), it was considered more appropriate not to apply the intention-to-treat principle and a per protocol analysis was carried out .Percentages, means, and standard deviations (SD) were calculated according to the nature of the variables in order to describe the characteristics of each individual in the sample. The assumption of normality was assessed using the Kolmogorov–Smirnov test and, if fulfilled, the corresponding parametric tests were carried out.t-Student test was used to determine the impact of the intervention on the number of risk factors and symptoms identified. All analyses were performed using SPSS® (version 24.0) software from IBM®.Chi-squared and McNemar’s tests were used to calculate differences between qualitative variables, percentage of breast cancer risk factors and symptoms identified and adherence to recommendations on diet and physical activity, in post-test between groups and change from pre-test to post-test, respectively. n = 134) and the CG (n = 90), participated in the intervention phase  failed to complete the post-intervention questionnaires  compared to women in the CG  after the intervention with a moderate to higher association  for the CG, and a mean of 9.38 (SD = 1.789) for the IG. Differences in this respect were not significant between the groups.The results of our study confirm that a web-app-based educational intervention can improve the level of adherence to dietary and physical activity, in 8 of 12 recommendations, as well as the level of knowledge, improved from pre-intervention to post-intervention for 6 risk factors and 6 symptoms, among women without a breast cancer diagnosis aged 25–50.There are two relevant aspects to consider in the design of the intervention. On the one hand, the active role granted to the participants. Various researchers suggest that breast cancer prevention policies should include strategies involving women in developing healthy lifestyles . On the The content of the web-app was similar to the one employed in previous interventions using webpages  and otheSatisfactory outcomes have also been observed among women participating in interventions facilitating knowledge acquisition, as well as in previous studies using a web-app as a medium to disseminate information about cancer prevention .After the intervention, women in the IG identified a higher number of risk factors than before the intervention than women in the CG. Awareness of risk factors is essential to enable women to take an active role in eliminating them  through Similarly, women in the IG significantly improved their knowledge of breast cancer symptoms. Knowledge of these symptoms encourages early identification, allowing for immediate effective diagnostic tests and early treatment if needed, which is related to improved disease progression . SymptomAn improvement in the behavior of both groups was observed, although it was only significant in the IG. Physical activity and a healthy diet have a positive and clearly established impact on breast cancer. The risk of developing breast cancer decreases in women who engage in regular physical activity  and in tTherefore, an intervention based on the use of a web-app such as the one described in this study can achieve an increase in knowledge of the disease as well as behavioral changes. In view of the results obtained using the web-app the next step could be to regularly offer this intervention as a supplementary resource for all women to address some of the clinical challenges faced by health services in preventing breast cancer .The strengths of this study include the alignment of its objectives with one of the priorities identified by the European Commission . For exaThe limitations of this study include those inherent to any study of this kind. Although the results point to an estimate of a real-life implementation, it is still necessary to conduct randomized experimental studies with a larger population to compare the results. The online format of the intervention and the self-reporting of information by participants may have introduced obsequiousness bias in relation to behavioral variables, including the impossibility of verifying that it was indeed the participant who was completing the questionnaires. However, considering the nature of the questions and the relevance of breast cancer as a health problem affecting many women, we believe that these limitations may not be significant. This study had a 30% drop out rate, what could be considered as bias. Nonetheless, even the causes were not assessed, is important to highlight that the intervention was carried out during initial phase of COVID pandemic, and we hypothesize that it could explain both why the post-test intervention was minor than the pre- intervention participation (before COVID).The preliminary results of this study suggest that the educational intervention, using a web-application based on the Behaviour Change Wheel model, was useful for improving knowledge of breast cancer risk factors and symptoms, as well as improving adherence to a healthy diet and physical activity among women without a previous diagnosis of breast cancer. Nonetheless, randomized controlled trials should be conducted in the future to provide more rigorous evidence of the effects of educational interventions based on the use of web-apps in enhancing early detection and prevention of breast cancer.Supplementary file1 (DOCX 14 KB)Supplementary file2 (DOCX 19 KB)Below is the link to the electronic supplementary material.