BackgroundBreast cancer is the most common of all female cancers worldwide. A large percentage are diagnosed at a late stage, which can be related to awareness and knowledge deficiency. We aimed to assess the level of knowledge of and attitude to breast cancer and breast self-examination in Jeddah, Saudi Arabia.MethodologyA descriptive cross-sectional study was carried out among 392 women in Jeddah, Saudi Arabia. Using a non-probability sampling technique, a self-administered validated questionnaire was distributed via social media. Inclusion criteria were ages above 18 years old of all educational levels.ResultsOut of 392 participants, there were 146 in the age group of 19-25 (37.2%). Most of the participants are aware of breast cancer (94.9%). The mean knowledge score was 6.9 ± 3.36. Ninety-two percent (92%) of participants had poor knowledge. Most respondents reported that the main risk factor for breast cancer was family history (83.7%). About 37% believed that the purpose of the breast self-examination practice is advice from a health care professional followed by routine examination (37.3%). About 97% agreed that early detection of breast cancer increases the chance of recovery.ConclusionThere is a lack of knowledge and awareness about the risk factors and symptoms of breast cancer. Despite a positive attitude toward breast self-examination, it is poorly practiced. Breast cancer became the most common of all cancers around the world with approximately 2.3 million new cases in 2020, overtaking most of the cancer percentages, over lung cancer. It has become the reason for 685,000 deaths worldwide ,2.In Saudi Arabia (SA), the number of new cases and the chance of mortality for breast cancer has been increasing over the years. By 2030, the number of new cases is expected to reach 3549. In 2016, the cases reported reached 3400. In addition, 50% of cases are diagnosed at a late stage as compared to 20% in developed countries [Several causes, including the decreased level of awareness, poor education, wrong beliefs, and cultural barriers, may justify the high percentage of late diagnoses and deaths of breast cancer ,7. MammoThe level of knowledge and awareness among females regarding breast cancer along with the attitudes toward screening methods, including the performance of BSE and being familiar with how their breasts should normally look and feel, are crucial factors in the process of early detection of breast cancer, which is essential in reducing breast cancer-related morbidity and mortality, as treatment is highly effective in the early stages of the disease ,8,10. A Due to late detection and rapid morbidity growth in previous years, it raises the future concern of breast cancer, therefore, we aim to assess the level of knowledge of and attitude toward breast cancer and BSE among females in Jeddah, Saudi Arabia.Study groupWe conducted a descriptive cross-sectional study from April to September 2022. Our study sample included all females of any educational level and aged above 18 years old in Jeddah. The sample size was estimated by using the Raosoft sample size calculator . ConsideQuestionnaireWe used a previously validated and published questionnaire with permission . The queData collection, processing, and analysisThe online self-administered questionnaire was distributed to the female population via social media, using a snowball non-probability sampling technique, and participants were encouraged to share it. Data entry was done by using Microsoft Office Excel 2016 . Categorical data are described in numbers and percentages using tables and figures while continuous data are presented as means and stander deviation. A one-way analysis of variance (ANOVA) test was done to assess differences in knowledge scores in relation to demographic characteristics. Statistical significance will be defined as a P value of less than 0.05, with a confidence interval of 95%. The statistical analysis was done by the Statistical Package for the Social Sciences (SPSS) software version 25 .Ethical considerationsThis study was approved by the Bioethics Committee for Scientific and Medical Research at the University of Jeddah . The consent was written on the first page of the questionnaire, stating that by submitting this questionnaire you agree to participate in the study. All information was kept confidential and only used for the purposes of scientific research.Out of 392 participants, there were 146 in the age group of 19-25 (37.2%). Half of our participants were married . The majority were Saudis . More than half of the participants have a bachelor's degree . The participants’ mean knowledge score was 6.9 ± 3.36. Only 8% of the participants had a good level of knowledge while the remaining 92% had a poor level of knowledge (Table Most of the participants are aware of breast cancer 372 (94.9%). Social media was the highest source of information regarding breast cancer 142 (37.8%) (Table The majority of the respondents reported that the main risk factor of breast cancer was family history (83.7%) followed by radiation exposure (50.0%), and old age and diet (30.9%). Nipple changes, nipple secretions, breast lumps, and changes in breast size and shape are the major symptoms of breast cancer Table .A breast lump was the most reported symptom of breast cancer (88.5%) followed by nipple changes (67.6%) and changes in breast size and shape (63.5%) Figure .Regarding knowledge of BSE, more than half of the respondents had heard about BSE but were without BSE practice 57.9%) because they had other reasons (46.0%). About 37% believe that the purpose of BSE practice is advice from a healthcare professional followed by a routine examination (37.3%). About 97% agreed that early detection of breast cancer increased the chance of recovery, and 82.1% agreed that females over 20 years should practice BSE frequently . The present study also confirmed that though most women have heard of breast self-examination, only a limited number perform it, and the reason was that they were too busy.Our result regarding knowledge of breast cancer was consistent with the Alshahrani study in that most of the participants were aware, and social media was the most common source of information . In the Regarding BSE, the majority of our respondents stated that they heard about it but only one-third practiced it. Additionally, the main reasons for practicing BSE were either advice from a healthcare professional or routine examination. A similar pattern of results was obtained in the Alshahrani and Alrawili studies ,15. SurpThe different results of this study have important implications for breast cancer studies, probably due to the different healthcare systems, social classes, sample distribution, age groups, regions, and qualifications. Furthermore, these differences, particularly in the recognition of risk factors and symptoms, suggest the need for further research to better understand the factors that contribute to differences in breast cancer knowledge and attitudes among different populations in Saudi Arabia. Such research could inform the development of more effective and culturally appropriate breast cancer awareness and early detection programs.The differences between the results of our study and others are likely due to variations in healthcare systems, social classes, sample distribution, age groups, regions, and educational levels. Moreover, differences in the recognition of risk factors and symptoms emphasize the need for further research to better understand the factors that contribute to variations in breast cancer knowledge and attitudes among different populations in Saudi Arabia.This study has some limitations. The generalizability of the study's findings may be limited due to the non-probability sampling method and the use of a self-reported online questionnaire, which could lead to recall and social desirability biases.This study showed a lack of knowledge and awareness regarding the risk factors and symptoms of breast cancer. In addition, BSE is believed to be a useful tool in conservative societies such as Saudi Arabia. However, they showed a poor practice of BSE. On the other hand, there is an excellent attitude toward it. Social media and relatives/friends were the main sources of information regarding breast cancer. We recommend including BSE as a subject in schools and universities for females and implementing community health campaigns in shopping malls and various public gatherings to increase knowledge and practice, which will decrease breast cancer morbidity and mortality rates.


High breast density on mammography is a well-established risk factor for a breast cancer diagnosis ,2. ThereIn this issue of The Breast, Dr Sturesdotter and colleagues investigate the first part of this question  in over 1100 women diagnosed with invasive cancer who were participating in the Malmö Diet and Cancer study . Using tLack of adjustment for stage and other unmeasured confounders may bias estimates of association between mammographic appearances and long-term prognosis. Figure 1 explores possible effects that unadjusted confounders may have for the case of screen detected cancers . UnmeasuThe method of measurement of breast density on mammography may also be important. Density measured using the “qualitative” 4 category Breast Imaging Reporting and Data System  has been found to predict risk of breast cancer diagnosis, with both as a single density measurement ,2, and cWith the transition to digital mammography , quantitThe overall negative findings from the current Malmo study offer some reassurance that while dense breast tissue is a risk factor for breast cancer, it may not affect prognosis once cancer is diagnosed. However, this should be interpreted with caution due to potential confounders and the possibility that breast-specific mammographic density changes over time may provide prognostic information on health outcomes beyond the cancer diagnosis. Future research seeking to investigate that hypothesis should include consideration of ways to account for potential confounders including cancer stage and overdiagnosis.10.13039/501100000925NHMRC Investigator Grant (#1174523). The funder played no role in the study design, in the collection, analysis and interpretation of data; in the writing of the manuscript; and in the decision to submit the manuscript for publication.KB is the recipient of an None declared.


Younger women are often diagnosed with advanced breast cancer. Beliefs about risk are instrumental in motivating many health protective behaviours, but there may be confusion around which behaviour is appropriate to detect breast cancer earlier. Breast awareness, defined as an understanding of how the breasts look and feel so changes can be identified early, is widely recommended. In contrast, breast self-examination involves palpation using a specified method. We aimed to investigate young women’s beliefs about their risk and experiences of breast awareness.Thirty-seven women aged 30–39 years residing in a North West region of England with no family or personal history of breast cancer participated in seven focus groups (n = 29) and eight individual interviews. Data were analysed using reflexive thematic analysis.“Future me’s problem” describes why women perceive breast cancer as an older woman’s disease. Uncertainty regarding checking behaviours highlights how confusion about self-checking behaviour advice has resulted in women infrequently performing breast checks. Campaigns as a missed opportunity highlights the potential negative effects of current breast cancer fundraising campaigns and the perceived absence of educational campaigning about breast cancer for this demographic.Three themes were generated. Young women expressed low perceived susceptibility to developing breast cancer in the near future. Women did not know what breast self-checking behaviours they should be performing and expressed a lack of confidence in how to perform a breast check appropriately due to limited knowledge about what to look and feel for. Consequently, women reported disengagement with breast awareness. Defining and clearly communicating the best strategy for breast awareness and establishing whether it is beneficial or not are essential next steps.The online version contains supplementary material available at 10.1186/s12905-023-02441-w. Epidemiological studies from the past decade have illustrated the growing burden of breast cancer in pre-menopausal women worldwide –4. CompaRecommendations for what behaviours women should be performing to facilitate early detection of breast cancer has changed over time. From 1950, teaching breast self-examination (BSE) to women by healthcare professionals was recommended. BSE is the palpation of a woman’s breasts for self-detection of breast cancer at a specific time each month according to a rigorous set method . The samHealthcare professionals have expressed concerns that the distinction between breast awareness and BSE is unclear, with references to both terms in the same guideline documents potentially causing confusion for both healthcare professionals and women . There iBreast awareness recommendations indicate women should be engaged in self-checking behaviour . To undeThe present analysis reports on data collected from a study which had the primary aim of investigating women’s views on, and requirements for, the delivery of breast cancer risk assessment . HoweverSpecific objectives were to:Explore women’s understanding of breast cancer risk.Identify the factors contributing to women’s beliefs about their own breast cancer risk.Explore women’s understanding and experiences of breast awareness.A cross-sectional qualitative design was used. As the topic of risk assessment and screening was theoretical to participants, focus groups were deemed the most appropriate method of facilitating discussion. Focus groups allow for reflection and clarification of perspectives, adding depth to the data . They alParticipants were recruited through responding to study advertisements outlining the topic and inclusion criteria. Participants were eligible if they were: [1] born female, [2] aged 30–39 years, [3] residing in Greater Manchester in England,  able to Advertising posters were shared on Facebook and Twitter and were also displayed on noticeboards in three local libraries and community centres. After seeing an advertisement on Twitter, the co-founder of a local ethnic minority organisation made direct contact with the research team and facilitated the recruitment of four members of their community. Prospective participants were screened against inclusion criteria via email/telephone and sent participant information sheets.The topic guide was developed to address the primary aim of the study, which was to investigate young women’s views on, and requirements for, the delivery of breast cancer risk assessment, and informed by a review of the literature . The lead author developed an initial draft and this was reviewed by public contributors and the rest of the research team who have expertise in medical oncology, breast cancer and screening services, health services research, health psychology and qualitative methods. The content and structure of the topic guide was revised in line with the feedback received. Data were collected between February and November 2020, at first in person then later via telephone and Zoom conferencing due to COVID-19 restrictions. Participants gave demographic information  prior to data collection. The full residential postcode of participants was used to extract the Index of Multiple Deprivation decile, a measure of relative deprivation for small areas in England, with 1 representing the most deprived 10% of small areas in England and 10 the least . Data wePublic contributors were involved in the design of this study. A research advisory group, consisting of five minority ethnic community leaders, advised on the research idea and intended recruitment procedures. Wording and terminology used in the recruitment poster and participant information sheet was revised following feedback from nine Black African women aged 30–39 years. During topic guide development, four White women aged 30–39 years advised on wording of questions, prompts and flow.The lead author (SH) was a White British female doctoral researcher with a background in Psychology. She has worked in cancer prevention and early detection research for six years, both reflecting and shaping her positive views of early cancer detection initiatives. SH is 31 years old meaning she was cognisant of the participant’s life stage and had life experiences in common with some of her participants, for example cervical screening. Other members of the research team were a breast cancer clinician working in cancer prevention and early detection and experienced academics who have reservations about the extent to which prevention and early cancer detection initiatives allow for informed choices about participation. The data resonated with feminist views of the team meaning that data analysis and interpretation were informed by a desire to legitimise and honour women’s absent or silenced experiences.The present analysis included responses to questions focused on comprehension of breast awareness, confidence in being breast aware, and awareness and thoughts about the current breast cancer incidence and mortality rates in younger women . This data was coded during the initial coding of the complete dataset but it did not form part of the framework for answering the primary aim of the study which was to understand women’s views on, and requirements for, the delivery of breast cancer risk assessment . The indData were analysed using reflexive thematic analysis as this allows the flexibility to combine multiple sources of data and is suited to research examining views about particular phenomena , 29. A cImportant techniques for ensuring quality reflexive thematic analysis are the researcher’s depth of engagement with the data and reflexive practice, rather than measures of accuracy or reliability . The leaThirty-seven women took part; seven focus groups (participant range n = 3–5) and eight interviews were conducted. Focus groups ranged from 71 to 90 min (median 85 min) with five conducted via Zoom conferencing and two face-to-face. Interviews lasted between 40 and 81 min (median 55 min) with five conducted by telephone and three face-to-face. Most participants were White British . Women attributed this perception to the organisation of the NHS breast screening programme which invites women aged 50–70 + years. Participants reported that given finite NHS resources, they assumed that breast screening is offered when the likelihood of developing breast cancer is greatest. The absence of a breast screening programme for younger women and lack of communication from healthcare professionals regarding breast awareness was perceived to indicate lesser risk for this age group, as women expected to be told by health authorities if they were at risk of developing a disease. Consequently, women expressed low perceived susceptibility to developing breast cancer.I thought the risk went up after 50 and that’s the whole reason that we have the screening after 50 .I think we believe innately that if we’re at medical risk, we’ll just be told about it. Yeah, or we would expect to hear from the doctors about it or, you know, it would be more present in our minds, yeah. Participants conceptualised breast cancer as an ‘older woman’s disease’. Many participants said they did not perceive breast cancer as an immediate health concern, for example one participant stated it was Some women considered healthcare interactions like cervical screening and antenatal appointments as missed opportunities to discuss breast awareness and whether breast cancer was a relevant health concern for their age group. In line with this, women reported accessing limited, if any, information about breast health.I went to a doctor once, I was about twenty-two, and said, “Oh, I’ve got weird lumps in my breasts” And she went, “No, that’s just water retention” and was really dismissive […] I just think that it would be better for doctors not to turn around and tell you you’re far too young when you have a genuine concern. I’ve got breast cancer on my dad’s side. And I asked the GP what – whether that meant anything. And he was really like, “Whatever. You know, don’t waste my time,” kind of thing. Breast cancer as an ‘older woman’s disease’ has been reinforced further when women reported consulting healthcare professionals with breast health concerns or concerns about risk. Some women reported feeling embarrassed about seeking help because they feared wasting NHS time. Women described feeling like a burden throughout the care pathway, in both primary and secondary care interactions. Participants who spoke about their experiences of seeking help reported an absence of reassurance following clinical interactions. They reported feeling as though their concerns had been dismissed in Primary Care because of their age.“the guy who did the biopsy was like, almost seemed annoyed that I’d been sent there” . Women reported that these types of experiences might have a negative impact on future help-seeking behaviour:the thought of if I did find something again, went again, again there was nothing there, that feeling of again I’ve, sort of, wasted a bit of NHS time, not that anyone ever made me feel like that but I suppose I used to think, you know, how many times can you do this. Women who had experienced being referred to secondary care reported feeling reassured after undergoing further investigations and receiving the all clear but conversely this was also seen to confirm their fears of having wasted NHS time and resources. One woman told us that a secondary care healthcare professional’s demeanour during their clinical interaction left her feeling as though she had been referred unnecessarily for a biopsy, when I was back home anyway growing up there, cancer was not a prevalent disease […] it wasn’t something that was common as it is over here so when people move over here […] you feel like cancer’s not a thing that affects people of your kind. When considering cultural differences in breast cancer prevalence and screening, some Black African participants expressed the view that breast cancer was more prevalent in the UK in comparison to their home countries in Africa. This was attributed to differences in diet and environment. Furthermore, these participants described very few instances of and conversations about breast cancer in their communities, which may adversely affect performance of breast self-checking behaviours.I’d say that term doesn’t really mean much to me . Some women believed breast checks should be performed monthly and that a specific technique should be used, resulting in the perception there was a ‘correct’ method of checking. Contrary to these beliefs, participants reported infrequently performing breast checks and being unaware of the recommended frequency for enacting this behaviour. Women tended to engage in this behaviour only when prompted by a trigger such as hearing about a relative or peer’s breast cancer diagnosis or media coverage about breast cancer. Different reasons were reported for infrequent engagement with breast checking behaviour. For some women, the anxiety and fear of potentially detecting breast cancer was a barrier to performing the behaviour:you still have that anxiety don’t you of “oh gosh, could it be?” and I sort of notice within myself that I feel reluctance to check because of that which I know is silly. When asked for their understanding of being breast aware, women believed they should be regularly checking their breasts to know how they normally look and feel so any changes that are not normal for the woman can be detected and reported to a GP. For one participant, being breast aware did not hold any meaning, you already know that you should do it you just don’t know what to do. I’m breastfeeding at the moment so my boobs change on a daily basis […] at the moment, I’d have no idea if something was to do with that or if it was to do with something more, kind of, nasty I suppose. I don’t know what I’m feeling for, I’ve watched a YouTube video, I’ve watched it and thought, okay, my boobs don’t look like her boobs, but she’s doing all this […]. It didn’t help me. Most participants reported not routinely engaging in breast checking due to a lack of confidence in how to perform the behaviour and limited knowledge about what to look and feel for. More specifically, participants expressed difficulty in distinguishing between a concerning and normal change, given natural variation during a menstrual cycle and the impact of breastfeeding. In addition, women mentioned the individuality of breasts, in terms of differences in size and consistency, rendering video demonstrations somewhat ineffective.Taken together, these comments highlight that women are finding it difficult to identify their own baseline normal, the reference point needed to make decisions about which changes require action. As a result, training on how to check and education about normal changes was desired in order to increase confidence.‘pink and pretty’  in comparison with other cancers. Some believed this portrayal had the inadvertent consequence of lessening the seriousness of breast cancer:I think it’s interesting around how breast cancer is portrayed as well, it’s given a bit of a different thing like then say lung cancer or bowel cancer. It does seem a bit pink and fluffier and therefore a bit less scary in a way so therefore people don’t take it as seriously .It [breast cancer] feels like it’s the less serious of the cancers if that makes any sense [laughs]. It’s like you’ve got your cervical cancer and your bowel cancer and your prostate cancer, and breast cancer is somewhere down the list. Breast cancer was perceived to have a high profile in the media. Women were familiar with fundraising campaigns such as Race for Life  and Wearyou get like breast cancer awareness month but besides people wearing ribbons I don’t know really what that’s saying to the world, it’s just oh breast cancer exists which we all know but we don’t know how to avoid that or what we can do about that, so there’s nothing, as far as I’m aware, there’s nothing preventative that’s being put out there .In contrast to fundraising campaigns, women reported limited exposure to educational campaigns aimed at their age group for raising awareness of breast cancer symptoms, risk-reducing measures and preventive strategies. This was evidenced further by a lack of knowledge about preventive measures. Many women were familiar with CoppaFeel! , a breasyou have sex education why aren’t you having some sort of like body education like here is how you check yourself .When asked what an effective campaign would look like, women expressed a desire for campaigns focused on effecting behaviour changes relevant to breast health such as advice to reduce risk and checking breasts to increase help-seeking behaviour. Women recommended that campaigns should be delivered in line with their target audience’s preferred means of interaction. For this reason, social media was regarded as the platform of choice for delivery for women in this age group. Several women recalled having seen the ‘Cervical Screening Saves Lives’ national campaign from 2019 which included significant amounts of social media advertising. In addition, women thought it would be important to have a ‘face’ for any campaign in the form of a relevant celebrity or influencer who their age group could identify with and relate to in order to increase the likelihood of paying attention. Instagram was considered a particularly favourable platform because it would lend itself to more engaging visual content such as videos. Some women thought breast awareness should be taught in schools alongside sex education to form a habit of being breast aware from a younger age. The perceived benefit of this was to help normalise and encourage discussions about breast health with peers so it would become part of mainstream conversation.Participants perceived breast cancer as a distant future health concern and expressed low perceived susceptibility to developing the disease because of the focus of breast screening at 50 years and above. This perception has been reinforced further by women’s experiences of help-seeking whereby they felt their breast health concerns have been dismissed because of their age. Uncertainty about what women should be doing with respect to breast health was apparent resulting in infrequent reports of performing breast checks and hesitancy towards seeking help for breast health concerns. Women described the potential negative effects of current breast cancer fundraising campaigns in terms of lessening perceptions of the seriousness and severity of breast cancer and perceived absence of educational campaigning about breast cancer targeted at their age group.In the present study, women expressed low perceived susceptibility to developing breast cancer in the near future. Although women aged 30–39 years are at a lower absolute risk of developing breast cancer than older age groups, breast cancer is more frequently fatal in younger women than in those diagnosed aged over 50 years . As a reRisk perception has been found to influence the symptom interpretation process of help-seeking behaviour with those expressing low perceived susceptibility to breast cancer delaying help-seeking . FurtherWomen reported more exposure to fundraising campaigns compared to educational campaigns. This is consistent with breast cancer awareness messaging in recent years, which has shifted from a focus on diagnosis and prevention to fundraising efforts . For thiWomen reported infrequently performing breast checks despite believing they should be enacting the behaviour. In this study, lack of confidence in how to perform a breast check, distinguishing between normal and concerning changes, limited knowledge about what to look and feel for and fear of potentially detecting breast cancer were identified as contributing factors to women’s disengagement with breast checking behaviours. Additionally, aspects of BSE were evident in women’s understanding of breast awareness such as believing there was a recommended frequency to perform breast checks and a ‘correct’ method of checking. Inaccurate understandings of current recommendations for self-checking behaviour have also been found amongst women older than 50 years, whereby women explicitly cited engaging in BSE and only alluded to engaging in breast awareness . These fThe data analysed were responses to the broad introductory questions about breast awareness that were asked to ease participants into conversation before exploring the topic of primary interest which was the delivery of breast cancer risk assessment. Therefore, we did not ask any direct questions regarding beliefs about breast cancer risk. Nevertheless, women spontaneously chose to discuss this indicating it was an important topic to them and further probing of initial responses was conducted to obtain more in-depth information.Ethnic minority groups and those from a low socio-economic background are underrepresented in cancer prevention and early detection research despite being disproportionately affected by cancer . TherefoThis research has demonstrated that women aged 30–39 years report uncertainty about what they should be doing with respect to breast health and a lack of confidence in how to perform a breast check appropriately due to limited knowledge about what to look and feel for. Consequently, women reported disengagement with breast awareness. To what extent this disengagement is concerning remains unknown as breast awareness continues to be promoted without any evidence of benefit. In the absence of clear evidence of benefit, future research should attempt to define the best strategy, in terms of recommended behaviours, for breast awareness. This could facilitate consistent messaging so women know what they should be doing.In the meantime, breast cancer charities should consider delivering and evaluating an educational campaign targeted at this demographic which clearly specifies which breast changes to be concerned about if identified. This is particularly important given current interest in offering breast cancer risk assessment to young women which will be highlighting the importance of remaining breast aware and performing breast checks in risk feedback. Further research with minority and marginalised groups including transgender individuals should be conducted to inform the design of future campaigns, as they are likely to have different needs and therefore recommendations for breast awareness communication . The rolThe present study also highlighted that young women do not perceive breast cancer as a relevant and immediate health concern. This perception has been reinforced by clinical interactions with healthcare professionals who were dismissive about breast health concerns. Therefore, future qualitative research should examine primary healthcare professionals’ understanding of breast cancer risk and referral decision-making for young women to inform the development and evaluation of educational interventions aimed at improving consultations about breast health concerns amongst this age group.Women aged 30–39 years perceived breast cancer as a future health concern. They reported not knowing what breast self-checking behaviours they should be performing and expressed a lack of confidence in how to perform a breast check appropriately due to limited knowledge about what to look and feel for. Consequently, women reported disengagement with breast awareness. Defining and clearly communicating the best strategy for breast awareness and establishing whether it is beneficial or not are essential next steps.Below is the link to the electronic supplementary material.Additional file 1: Focus group and interview topic guide.


Epithelial-to-mesenchymal transition (EMT) is an important cause of high mortality in breast cancer. Twist1 is one of the EMT transcription factors (EMT-TFs) with a noticeably short half-life, which is regulated by proteasome degradation pathways. Recent studies have found that USP13 stabilizes several specific oncogenic proteins. As yet, however, the relationship between Twist1 and USP13 has not been investigated.Co-Immunoprecipitation, GST-pulldown, Western blot, qRT-PCR and immunofluorescence assays were used to investigate the role of USP13 in de-ubiquitination of Twist1. Chromatin immunoprecipitation and Luciferase reporter assays were used to investigate the role of Twist1 in inhibiting USP13 reporter transcription. Scratch wound healing, cell migration and invasion assays, and a mouse lung metastases assay were used to investigate the roles of USP13 and Twist1 in promoting breast cancer metastasis.We found that Twist1 can be de-ubiquitinated by USP13. In addition, we found that the protein levels of Twist1 dose-dependently increased with USP13 overexpression, while USP13 knockdown resulted in a decreased expression of endogenous Twist1. We also found that USP13 can directly interact with Twist1 and specifically cleave the K48-linked polyubiquitin chains of Twist1 induced by FBXL14. We found that the effect of USP13 in promoting the migration and invasion capacities of breast cancer cells can at least partly be achieved through its regulation of Twist1, while Twist1 can inhibit the transcriptional activity of USP13.Our data indicate that an interplay between Twist1 and USP13 can form a negative physiological feedback loop. Our findings show that USP13 may play an essential role in breast cancer metastasis by regulating Twist1 and, as such, provide a potential target for the clinical treatment of breast cancer.The online version contains supplementary material available at 10.1007/s13402-023-00779-9. Breast cancer is a highly heterogeneous disease and the most common malignancy among female cancer patients worldwide, with a high incidence rate  and second only to lung cancer in mortality  in 2022 .Twist1 (twist family bHLH transcription factor 1) is an efficient EMT-TF . This trUSP13 (ubiquitin specific peptidase 13), a member of the de-ubiquitinating enzyme (DUB) superfamily , has beeHere, we investigated a potential physical/functional interaction between Twist1 and USP13 in human breast cancer. We found that USP13 promotes breast cancer metastases through Twist1 de-ubiquitination. Targeting the USP13/Twist1 axis may provide an option to treat this fatal disease effectively.2 at 37 °C, and the media were supplemented with 10% FBS (NQBB), 100 μg/ml streptomycin, and 100 μg/ml penicillin (Solarbio).The use of human HEK293T, mouse 4T1/Luc and human breast cancer  cells has been reported in our previous studies , 37. T47The commercial antibodies used for Western blot analysis are as follows: anti-Twist1 , anti-USP13 , anti-RNF8 , anti-FBXL14 , anti-βTrcp1 , anti-E-cadherin , anti-N-cadherin , anti-Vimentin , anti-MMP9 , anti-Ubiquitin , anti-Flag , anti-GFP , anti-HA , anti-c-Myc , anti-GST , anti-GAPDH , anti-tubulin , and anti-Ubiquitin K48-specific antibody . Anti-Flag Affinity Gel (B23102), Poly Flag Peptide (B23111) and Protein A/G mix magnetic beads (B23202) were obtained from Bimake Chemicals. Cycloheximide (S7418) and MG132 (S2619) were obtained from Selleck Chemicals. TGF-β1 (100–21) was obtained from Peprotech.pcDNA3.1-Flag-Twist1 was kindly provided by Dr Cheng Yang , pRK-GFP-USP13 and pRK-GFP-USP13AE were kindly provided by Dr Bo Zhong , pcDNA3.1-HA-FBXL14 was kindly provided by Dr Bin Wang . The GFP-Twist1 plasmid was generated by inserting a Twist1 DNA fragment into a pEGFP-C1 vector at the BglII and BamHI sites by standard PCR using specific primers and Flag-Twist1 as template. The GST-USP13 and GST-USP13AE plasmids were generated by inserting USP13 or USP13AE DNA fragments into a pGEX-GST vector at the EcoR1and XhoI sites by standard PCR using specific primers and GFP-USP13 as template. Deletion mutants of GFP-Twist1 and GFP-USP13 were generated by standard PCR using specific primers and GFP-Twist1 and GFP-USP13 as templates separately. The USP13-promoter-Luc plasmid was constructed by inserting a 1,701 bp DNA fragment upstream of the USP13 transcriptional start site into a pGL3-basic vector at the KpnΙ and NheΙ sites. The fragment was cloned from SUM159PT cell DNA using sense primer 5′-TCTTTTCAATGGTACTGTATTTTAACC-3′ and antisense primer 5′-GGCGACGCTATTTTTAATCCAATGGCG-3′. shRNAs specific for USP13 and Twist1 were inserted into a pRNAT-U6.1/Hygro cloning vector. The sequences used were as follows: 5′-GTGATTGAGATGGAGAATA-3′ (#1), 5′-GGGAACATGTTGAAAGACA-3′ (#2) for shUSP13 and 5′-CTGAACAGTTGTTTGTGTT-3′ (#1), 5′-GGACCCATGGTAAAATGCA-3′ (#2) for shTwist1. The pcDNA3.1–3 × Flag empty vector, as well as the HA-Ub, HA-K48 and HA-K63 plasmids were used in our previous studies . Cells wCo-Immunoprecipitation (CoIP), Western blot (WB) and chromatin immunoprecipitation (ChIP) assays were performed as previously described . For theGST-pulldown assay and immunofluorescence (IF) were carried out as reported before , 39. For−ΔΔCT method [Total RNAs were extracted by RNAios Plus  after which reverse transcription was carried out to synthesize cDNA as previously reported . QuantitT method  with GAPHEK293T cells were transfected with Flag-Twist1 and HA-Ub plasmids after which immunoprecipitation was carried out to obtain ubiquitinated Twist1 from the indicated cells using Anti-Flag Affinity Gel. Next, the immunoprecipitates were eluted by Poly Flag Peptide (0.5 mg/ml) after which the eluates were incubated with GST-USP13 or GST-USP13AE at 37 °C for 2 h followed by incubation at 16 °C in the presence of ATP (1 μM) overnight. Finally, the co-incubated samples were analyzed by Western blotting.6 cells per well) in 6-well plates. After 24 h, a pipette tip (200 μl) was used to create a scratch wound. Next, the cell cultures were washed using phosphate-buffered saline (PBS) and incubated afterwards. The wounds were photographed under a microscope at 0 and 24 h in situ to compare the number of cells that migrated into the wound areas.For the scratch wound healing assay, cells were seeded  or empty Transwell inserts. The Matrigel was also diluted in serum-free medium to 5 mg/ml. The bottom compartments of the chambers contained complete medium as chemoattractant. The inserts were removed and rinsed with PBS after 24 h after which the cells on the bottom side were stained with crystal violet and evaluated by microscopy.Migration and invasion assays were carried out using Transwell inserts containing 8-μm polycarbonate membranes . 1 × 106 stably transfected 4T1/Luc cells in 0.2 ml normal saline were subcutaneously injected into the mice through the tail vein. After 14 days, metastatic lung foci were detected using bioluminescence imaging before all mice were sacrificed to collect the lungs. According to standard protocols, the lungs of each group were processed for Western blot and immunohistochemistry (IHC) assays and for hematoxylin–eosin (HE) staining, respectively.7-week-old female BALB/c mice were purchased from Liaoning Changsheng Biotechnology company and divided into four groups randomly (5 mice per group) before injection, and fed in the same environment. 2 × 10p-value. Differences were considered significant when p < 0.05 (*p < 0.05), and extremely significant when p < 0.01 (**p < 0.01).All data were analyzed by GraphPad Prism 8.0.1 software and are presented as mean ± standard deviation (SD). Each experiment was conducted at least three times with consistent results. Statistical analyses were performed using a two-tailed t-test to evaluate statistical significance, expressed as http://ualcan.path.uab.edu/) [https://xenabrowser.net/) and analyzed by the R package survival [The authors declare that the data supporting the findings of this study are available within the paper. The USP13 expression level analyses between normal breast tissues and different subclasses of carcinomatous breast tissues are available in ULACAN (ab.edu/) , and thesurvival  and survsurvival  tools.All animal experiments were performed according to the regulations set by the Ethics Committee for Biology and Medical Science of Dalian University of Technology.http://ualcan.path.uab.edu/), we found a significantly higher USP13 expression (p < 0.01) in highly metastatic triple-negative breast cancers compared to the other two breast cancer subclasses  at different time intervals to block new protein synthesis. Compared with the empty vector control group, we found that the protein level of Twist1 was significantly stabilized in the presence of USP13 Fig. , rather In light of the known capability of Twist1 to link K48 and K63 ubiquitin chains, we speculated that USP13 may be able to deubiquitinate K48 or K63 ubiquitinated Twist1. In fact, we found that USP13 overexpression caused a drop in K48 levels, but not of K63 ubiquitination on Flag-Twist1 Fig. . As mentTo fully explore the interplay between USP13 and Twist1, we examined the role of USP13 in inducing breast cancer cell migration and invasion through Twist1. We found that in two cell lines, T47D and ZR-75–30, which represent typical luminal cells with undetected endogenous Twist1 expression, the expression of USP13 significantly increased the levels of Twist1 and its downstream proteins Fig. . In addiWe also assessed the effects of USP13 expression on lung metastasis of breast cancer to further substantiate the above in vitro findings. We found that BALB/c mice injected with USP13 overexpressing 4T1/Luc cells had more lung metastatic nodules than those in the control group. The results of HE staining showed an increased proportion of nuclear atypia in lung sections of mice injected with USP13-overexpressing 4T1/Luc cells, including abnormal nuclear size and darker nuclear staining, revealing the severity of lung metastases from mammary tumors , 45. MeaWith Twist1 being a transcriptional factor and sequence analysis of the USP13 promoter from position -1850 to + 49 showing three putative Twist1 binding sites , we assumed that Twist1 may affect the transcription of the USP13 gene Fig. . Using lBreast cancer is the most common cancer in women worldwide, ranking second in the global female cancer mortality rate . Most brDuring the initial stages of EMT, the expression of EMT-TFs is abnormally activated, which inhibits the expression of E-cadherin and promotes tumor progression . EMT-TFsAs an important EMT-TF, Twist1 is highly expressed in breast cancer patients. Its expression is further elevated in highly aggressive triple-negative breast cancer cells compared to other breast cancer cells . Next toAs a typical transcription factor, Twist1 can recognize and bind to the E-box region of downstream gene promoters to activate or inhibit the transcription of target genes . By analWe found that USP13 and Twist1 can form a negative feedback loop to jointly regulate the migration and invasion of breast cancer cells. This finding may facilitate the identification of new therapeutic targets to treat patients with breast cancer.Supplementary file1 (PDF 792 KB)Below is the link to the electronic supplementary material.


Women with BRCA1 and BRCA2 (BRCA1/2) pathogenic/likely pathogenic (P/LP) variants have a higher risk to develop breast and ovarian cancer. In structured high-risk clinics, risk-reducing measures are adopted. This study aimed at characterizing these women and identify factors that may have influenced their choice between risk reduction mastectomy (RRM) and intensive breast surveillance (IBS).This study reviewed retrospectively 187 clinical records of affected and unaffected women with P/LP variants of the BRCA1/2 genes, from 2007 to 2022, of which 50 chose RRM, while 137 chose IBS. The research focused on personal and family history and tumor characteristics and their relation with the preventive option chosen.p = 0.049), with younger age determining the option for RRM . Among women with personal history of ovarian cancer, a higher proportion opted for RRM compared to those without that history , with younger age determining the option for RRM . Women who had bilateral salpingo-oophorectomy were more likely to choose RRM than those who did not . Family history was not associated with preventive option .Among women with personal history of breast cancer, a higher proportion opted for RRM compared to those asymptomatic (34.2% vs 21.3%, The decision for the preventive option is multifactorial. In our study, personal history of breast or ovarian cancer, younger age at diagnosis, and previous bilateral salpingo-oophorectomy were associated with the choice of RRM. Family history was not associated with the preventive option.The online version contains supplementary material available at 10.1007/s00432-023-04663-9. BRCA1 and BRCA2 (BRCA1/2) genes. These variants also increase the risk of developing cancer in other organs, especially in the ovary  or intensive breast surveillance (IBS). RRM has been shown to reduce breast cancer risk by more than 95% .The increased risk of breast cancer at earlier ages leads to particular concern about preventive strategies in carriers of P/LP variants in BRCA1/2 genes who are followed in a High-Risk Breast Clinic, and to identify the factors that influence their choice for one of these breast cancer preventive options: RRM or IBS.The aim of this study is to characterize women with P/LP variants in BRCA1/2 genes were retrospectively identified at the Breast Center of the Centro Hospitalar Universitário de São João. The cohort consisted of women with BRCA1/2 P/LP variants diagnosed in the context of the Oncogenetic Clinics of the Centro Hospitalar Universitário de São João (genetic studies were carried out in the Genetic Department) and observed in a High-Risk Breast Clinic at the Breast Center from 30th November 2007 to 12th July 2022, who opted for a breast cancer preventive option: RRM or IBS, according to National Comprehensive Cancer Network guidelines . None of them was treated with chemo-preventive agents.Women with known P/LP variants in BRCA1/2 P/LP variants; parity; marital status; education level; smoking status; body mass index (BMI); age at genetic testing; personal history of breast cancer; personal history of ovarian cancer; personal history of other types of cancer; family history of breast cancer; family history of ovarian cancer; and breast cancer preventive option. In case of death, the date and cause of death was recorded.Clinical information was obtained through the patients’ digital records: age at the first appointment at the High-Risk Breast Clinic; Women with a personal history of breast cancer were considered symptomatic. In this group of women, more details concerning the breast cancer characteristics were collected: age at diagnosis, histologic type of cancer, type of surgery, other treatments, recurrence, and vital status.® SPSS® Statistics 27 program. Descriptive statistics were used to summarize the main characteristics of the sample. Quantitative variables were summarized by measures of central tendency  and dispersion (standard deviation) and qualitative variables were summarized by absolute (N) and relative (%) frequency. The Chi-square or Fisher’s exact test, as appropriate, was used for comparison of proportions, while Student’s t test or Mann–Whitney test was used for comparison of means or medians, respectively. A p value < 0.05 was considered statistically significant. Groups of patients who chose IBS or RRM were compared to identify factors related to the preventive option taken.The data collected from the clinical records were analyzed using the IBMThis study was approved by the Ethics Committee of Centro Hospitalar Universitário de São João and Faculdade de Medicina da Universidade do Porto (CE 124-22). The retrospective nature of the analysis supported the informed consent waiver, for the sake of feasibility. This research ensured the privacy of patient data, since any sort of personal information that allows identification was not used or shown in the database built.BRCA1/2 P/LP variants were included, with a median follow-up time of 37 months (0–168 months) from 2007 to 2022.Overall, 187 carriers of BRCA1 P/LP variants and 122 (65.2%) were carriers of BRCA2 P/LP variants.Table BRCA1/2, 79 (42.2%) had a personal history of breast cancer with the median age at diagnosis of this cancer of 42 (range 24–81) and 8 (4.3%) had a personal history of ovarian cancer with the mean age at diagnosis of this cancer of 50.1 (standard deviation: 12.4). Bilateral salpingo-oophorectomy was performed in 83 (44.4%) women in this group of carriers, of which 68 (81.9%) were for risk reduction purpose. A total of 9 (4.8%) had personal history of another type of cancer (apart of breast and ovarian), including kidney, pancreas, uterus, lung, brain, and colorectal. Regarding family history, 154 (82.4%) women had a family history of breast cancer, and 18 (9.6%) women had a family history of ovarian cancer.Of the 187 women with P/LP variants in BRCA1/2 P/LP variants was faced with the need to choose the preventive option for breast cancer, with 50 (26.7%) women choosing RRM and 137 (73.3%) women opting for IBS. Of the 50 women who chose RRM, 48 (84.2%) performed breast reconstruction, and of these, only one did not opt for immediate breast reconstruction. Of the women who opted for IBS, six (4.4%) developed breast cancer, with all of them being submitted to RRM of the contralateral breast. Of the asymptomatic women who opted for RRM, two (4%) developed breast cancer later.Following genetic diagnosis, this population of 187 women with Of the entire cohort, four (5%) women died. This corresponds to an overall survival of 95.7% (95% CI 88.3–98.5). Three deaths were not breast cancer related. The other woman died because of breast cancer progression. She belonged to the IBS group. This corresponds to a breast cancer-related mortality of 0.85% (95% CI 0.12–6.07).Table No significant sociodemographic differences were observed between the two groups.p = 0.049). These women were younger at breast cancer diagnosis in the group that chose RRM compared to those who selected IBS .Among those women with personal history of breast cancer, there was a higher proportion who opted for RRM compared to those without personal history of breast cancer . Younger age at diagnosis in women with a history of ovarian cancer also influenced the choice of RRM .Likewise, among carriers with personal history of ovarian cancer, there was a higher proportion of women who opted for RRM compared to those without personal history of ovarian cancer .Women who had bilateral salpingo-oophorectomy also opted for RRM in a higher proportion compared to those who had not been submitted to bilateral salpingo-oophorectomy , although this was a borderline result.Among carriers of n = 79). Of the 79 women with a personal history of breast cancer, 52 (65.8%) had P/LP variants in BRCA2 gene, while 27 (34.2%) had P/LP variants in BRCA1 gene. Regarding the breast cancer preventive option, 27 (34.2%) opted for RRM, while 52 (65.8%) opted for IBS. Of the 79 breast cancers, 61 (77.2%) were invasive and 18 (22.8%) were ductal in situ. Concerning laterality of the breast cancer, 62 (78.5%) were unilateral and 17 (21.5%) were bilateral.Table n = 52), three mastectomies had an initially risk reduction intention, considering that only in the final pathology result of the surgical specimen, the cancer diagnosis was revealed. In addition to surgical treatment, 67 (84.8%) of the symptomatic women performed chemotherapy, 51 (64.6%) radiotherapy, and 49 (62.0%) hormone therapy.All these symptomatic women underwent surgery, with 52 (65.8%) having therapeutic mastectomy and 27 (34.2%) having breast-conserving surgery. Of the 52 women who underwent therapeutic mastectomy, 36 (69.2%) had reconstruction, and of these, 25 (69.4%) were immediate reconstructions. In the group who underwent mastectomy as treatment for their breast cancer  had disease recurrence, three of them with local recurrence, one with regional recurrence, and three with distant recurrence . Of these seven patients, five chose RRM after the initial diagnosis of breast cancer, therefore before recurrence, and two opted for RRM only after recurrence.Table p = 0.008). While all carriers with more than one second-degree relative with ovarian cancer also opted for IBS, only 25% of those with only one second-degree relative with ovarian cancer chose the same breast cancer preventive approach (p = 0.033).All of those who had male family members with breast cancer chose IBS . This was not predictable considering some studies that showed a 15-year actuarial risk of contralateral breast cancer of 36.1% for women with P/LP variants BRCA1/2 in Portugal, regarding the choice for the preferred breast cancer preventive option.To the best of our knowledge, this is the first characterization of women with P/LP variants in These women were diagnosed, followed, and treated at a certified center, annually audited with several quality indicators Below is the link to the electronic supplementary material.


Breast cancer risk models guide screening and chemoprevention decisions, but the extent and effect of variability among models, particularly at the individual level, is uncertain.To quantify the accuracy and disagreement between commonly used risk models in categorizing individual women as average vs. high risk for developing invasive breast cancer.Comparison of three risk prediction models: Breast Cancer Risk Assessment Tool (BCRAT), Breast Cancer Surveillance Consortium (BCSC) model, and International Breast Intervention Study (IBIS) model.Women 40 to 74 years of age presenting for screening mammography at a multisite health system between 2011 and 2015, with 5-year follow-up for cancer outcome.Comparison of model discrimination and calibration at the population level and inter-model agreement for 5-year breast cancer risk at the individual level using two cutoffs (≥ 1.67% and ≥ 3.0%).A total of 31,115 women were included. When using the ≥ 1.67% threshold, more than 21% of women were classified as high risk for developing breast cancer in the next 5 years by one model, but average risk by another model. When using the ≥ 3.0% threshold, more than 5% of women had disagreements in risk severity between models. Almost half of the women (46.6%) were classified as high risk by at least one of the three models  for the threshold of ≥ 1.67%, and 11.1% were classified as high risk for ≥ 3.0%. All three models had similar accuracy at the population level.Breast cancer risk estimates for individual women vary substantially, depending on which risk assessment model is used. The choice of cutoff used to define high risk can lead to adverse effects for screening, preventive care, and quality of life for misidentified individuals. Clinicians need to be aware of the high false-positive and false-negative rates and variation between models when talking with patients.The online version contains supplementary material available at 10.1007/s11606-023-08043-4. These risk models differ in the number and weighting of variables included in their calculations. While age is the strongest predictor in all models, other components are variable and may include family history, genetic carrier status, and nongenetic risk factors such as breast density and previous breast biopsy.2 These commonly used risk prediction models have similar accuracy and good discrimination when assessed in large populations.5Breast cancer risk models estimate a woman’s risk of developing invasive breast cancer over a defined period, most commonly 5 years. These models have been developed and validated at a population level,11 and supplemental MRI screening.15 In 2019, the US Preventive Services Task Force recommended that clinicians offer risk-reducing medications, such as tamoxifen, raloxifene, or aromatase inhibitors, to women who are at high risk for breast cancer in the next 5 years and at low risk for adverse medication effects.10 While prior recommendations and clinical trials have supported using a 5-year risk cutoff of 1.67%, the Task Force in 2019 recommended a new cutoff of 3%. Previous publications have not adequately assessed the variation in risk estimates for the ≥ 3.0% 5-year threshold at the level of the individual. The few studies evaluating differences in model performance at the level of the individual woman have used small sample sizes and only evaluate lifetime risk,17 or report results for a 5-year threshold of ≥ 1.67%.18 Since key screening and medical intervention decisions are based on a woman’s estimated risk of developing invasive breast cancer, a consistent and accurate risk estimate is essential.While current breast cancer risk assessment tools work well at a population level, little attention has been paid to how they perform at an individual level or to the impact of different thresholds for defining high risk. As we move toward a precision medicine approach in healthcare, these risk models are increasingly being used to identify women who would benefit from chemoprevention19 the Breast Cancer Surveillance Consortium (BCSC),21 and the International Breast Intervention Study .22 The BCRAT and IBIS are thought to be the two most commonly used models in clinical practice in the USA.24 Moreover, these three models all have readily accessible simple online calculators and are recommended for use in primary care.25 In addition to assessing inter-model disagreement at the level of the individual, we used a subset of women with long-term cancer outcomes from cancer registry linkage to assess the accuracy of the risk models, as well as model calibration and discrimination at the population level.The objective of this study was to evaluate the accuracy and extent of disagreement of three common clinical risk models at the individual level when using these two different cutoffs (≥ 1.67% and ≥ 3.0%) to define high risk of breast cancer at 5 years. We focused on the models most likely to be used across all clinical specialties including, importantly, primary care and general internal medicine providers. The three risk models evaluated in this paper are the Breast Cancer Risk Assessment Tool ,26 Women participated at the time of mammography screening by completing informed consent and digital surveys that assessed their health history, lifestyle behaviors, and family history of cancer (IRB #10-001083). If a woman had multiple mammography examinations during the study period and thus filled out multiple surveys, the earliest most complete survey with the least amount of missing information was used. Overall, 50 variables were extracted from the survey and electronic health record to generate a dataset to use for the three risk models in this study. The key variables are listed in Table TM) was acquired from the mammography report. If multiple mammography screening exams were available for a woman, we used the one closest to the date when the woman completed the survey.Data from UCLA Health, a diverse, multisite US health system serving a large geographic region of Southern California, were used for this study. Data were collected as part of the Athena Breast Health Network, a statewide quality improvement initiative across the University of California medical and cancer centers.cer IRB #0-001083.29All women aged 40 to 74 years presenting for screening mammography between January 1, 2011, and December 31, 2015, were considered for inclusion for the primary analysis. For a subgroup of women who entered the study from 2011 to 2013, a minimum of five full years of follow-up data were available and breast cancer outcome data for these women were collected from the health system and regional cancer registry linkage. For women with invasive breast cancer, the last follow-up date is the date of diagnosis. For non-cancer cases, a full 5 years of follow-up data were available from the date of their survey. We identified 382 cases of invasive cancer in these asymptomatic women presenting for screening mammograms, of which 16 women died within 5 years, making the 5-year survival 97%. This 5-year survival is similar to that reported in other studies reporting the survival of women with invasive breast cancer detected by screening mammography.The study population included a mix of women on annual and biennial screening intervals, with more women screened in the health system in later years as capacity expanded. Patients were offered enrollment into the Athena Breast Health Network at each screening exam; therefore, patients may have only answered the survey questionnaire once but may still have had more than one subsequent screening exam during the study period. Women were excluded from our analysis if they had a previous diagnosis of invasive breast cancer or ductal carcinoma in situ (DCIS), prior breast augmentation, or prior mastectomy.30 BCSC software was downloaded from the Breast Cancer Surveillance Consortium.31 IBIS software  was downloaded from the Wolfson Institute of Preventative Medicine.32 Missing data for the IBIS model were prepared according to the instructions provided on the IBIS website .BCRAT software  was downloaded from the National Institute of Health, Division of Cancer Epidemiology & Genetics.10 The “average-risk” group includes what are likely to be both low- and average-risk women, two terms that are not well defined for 5-year risk by the existing models. Therefore, for the purpose of this study, we have grouped any women who were not high risk under the term “average risk.”Five-year breast cancer risk was calculated using the three different models for each woman. Women were divided into average- or high-risk groups for 5-year risk estimates using the cutoffs of ≥ 1.67% and ≥ 3.0%, the two values used by clinicians when considering chemoprevention treatment recommendations.We describe self-reported demographics and key breast cancer risk factors obtained at the time of imaging. Two-sided hypothesis testing on descriptive statistics employed chi-squared testing for categorical variables and non-parametric Wilcoxon test for continuous variables. We calculated population-level model performance based on calibration and discrimination for the subset of women with full cancer outcome data at 5 years. We assessed each model’s ability to discriminate between women who did and did not develop invasive breast cancer within 5 years by estimating and testing for differences in the C-statistic and plotting ROC curves. Calibration was assessed using both observed probability and predicted scores for 5-year breast cancer outcome from three models and plots by risk decile. Expected value is calculated as the sum of the predicted 5-year absolute risk estimated from each risk model. Observed value and the 95% confidence interval were calculated for a Poisson distribution. To compare binary 5-year risk between breast cancer risk models, we describe pairwise comparison in 2 × 2 tables. SAS version 9.4  was used to perform all statistical analyses.N = 11,589), 382 (3.3%) had an invasive breast cancer diagnosis within 5 years.Over the 5-year study period, 48,980 women presenting for mammography were surveyed, of which 36,438 women met the eligibility criteria for risk models, with 85.4% 31,115) of eligible women having the minimum recorded risk data to run all three models  for both the BCRAT and BCSC models. The percentages of 5-year high risk from this complete data were similar to that from the full data .The accuracy of classifications when using these risk models is shown in Table 34 our analyses highlight marked disagreement between models in who they identify as “high risk.” For example, more than 20% of women would be classified as high risk of developing invasive breast cancer in the next 5 years by one model but average risk by a second model if using the ≥ 1.67% threshold. We found that if all three models were used, almost half of women would be considered at high 5-year risk by at least one model when using the ≥ 1.67% cutoff. However, most women will not be diagnosed with breast cancer within 5 years, thus leading to many women being incorrectly classified as high risk.Breast cancer risk models are increasingly used in clinical care to provide more personalized, risk-based screening and prevention recommendations. In our analysis, we found substantial variability in categorizing individuals as high risk for developing invasive breast cancer based on the risk model and the 5-year cutoff used. Thus, women are likely receiving vastly different recommendations depending on which breast cancer risk model is used and which cutoff is used to define “high risk.” While these models perform similarly at the population level, as noted in our study and in prior studies,These findings highlight the tradeoff of sensitivity and inaccurate classification as being “high risk” when using the two different thresholds currently recommended to define high risk. For example, when using the ≥ 1.67% cutoff for considering chemoprevention, about half of the women diagnosed with a future breast cancer might be correctly identified as high risk, yet many more women will be falsely classified as high risk. When using the more conservative ≥ 3.0% cutoff, there will be a much smaller number of women incorrectly classified as high risk, yet most of the women with a future breast cancer diagnosis will be missed.25 In contrast, more specialized models such as BOADICEA (CanRisk) and BRCAPRO, while well validated, are recommended for use by genetics specialists or designed to assess the probability of specific genetic risk factors.38 Whether or not our findings of variable high-risk categorization at the individual level holds across these additional models should be explored in future studies.We focused on the BCRAT, BCSC, and IBIS models as they are commonly used models, readily accessible online, and recommended for use in primary care.42 Risk prediction based on objective imaging-based deep learning breast cancer risk models has the potential to remove the subjectivity involved with the use of self-reported risk information that currently drives risk-based screening and prevention practices.44 However, these new tools require having had a screening mammography examination and thus may not be useful to assess risk in the context of deciding what age to start screening.45While the current practice of shared decision-making based on women’s breast cancer risk estimates from these commonly used risk models is not precise, newer risk models are being developed. Some models are now including information on breast cancer susceptibility genes and genetic susceptibility variants, while several recent studies suggest that quantitative imaging biomarkers and artificial intelligence algorithms might also supplement or supplant the current, subjective clinical risk assessment tools.47 Finally, BCRAT and BCSC were developed to evaluate risk of invasive breast cancer, yet IBIS was developed to evaluate risk of invasive or ductal carcinoma in situ. In order to compare across models, we used the outcome of invasive breast cancer only for all three models.49This study has several limitations. The cohort was drawn from women enrolled in a longitudinal screening study. Although we had extensive risk factor data on many participants, some family history was missing as was data on polygenetic risk scores. Despite this, the percentage of women identified as high risk was similar for both those with complete and incomplete (minimum required) data for the BCRAT and BCSC models, suggesting that the most impactful risk factors were recorded for most women. Moreover, we suspect that the results based on the minimum number of risk factors required to calculate each model are more representative of how these models are likely used in real-world clinical practice, where risk factor data are typically self-reported. Several prior studies have demonstrated inconsistencies in a woman’s accuracy at remembering age of menstruation and other historical data.Our study has multiple strengths. First, we considered the differences in model performance at the individual level. The few studies that have done this are limited by small sample size, did not evaluate disagreement between models when a woman uses more than one risk model, or did not provide comparative evaluation using the more conservative 5-year risk threshold of ≥ 3.0%. Our analysis also uses data from a large racially and ethnically diverse population of women.In summary, we noted substantial discordance in how three commonly used clinical risk models predicted 5-year invasive breast cancer risk, especially when using the cutoff of ≥ 1.67% to define high risk. While risk models are generally considered useful in determining eligibility for high-risk screening and intervention at the population level, they may be less useful for guiding discussions about screening and interventions at the individual level. Our findings highlight the risk of a blanket approach to using risk prediction models to inform individual-level medical screening and treatment decisions. Future research efforts are necessary to improve on the ability of these risk models to inform shared decision-making for individual patients.ESM 1(DOCX 105 kb)