Patients with inflammatory bowel disease (IBD) have an increased risk of colorectal cancer, whether or not they are smokers. It is recommended to start screening 8-10 years after diagnosis of IBD (or earlier if primary sclerosing cholangitis or other events occur during this interval). The recommended techniques are colonoscopy with random biopsies (answer 3) and pancolonic chromoendoscopy with staining, which is currently the gold standard because it detects dysplasia better, although it requires more technical experience.

Patients with inflammatory bowel disease (IBD) have an increased risk of colorectal cancer, whether or not they are smokers. It is recommended to start screening 8-10 years after diagnosis of IBD (or earlier if primary sclerosing cholangitis or other events occur during this interval). The recommended techniques are colonoscopy with random biopsies (answer 3) and pancolonic chromoendoscopy with staining, which is currently the gold standard [HIDDEN], although it requires more technical experience.

A 60-year-old man with extensive ulcerative colitis of 15 years of evolution and in clinical remission for the last 3 years, comes to our office to be informed about the risk of colorectal cancer and about the possibility of participating in prevention programs. It is correct to inform him that:

Ulcerative colitis is only associated with an increased risk of colorectal cancer in smokers.

In her case, given that she is in long-term remission, the screening advised to the general population is considered appropriate.

In cases such as yours, it is considered appropriate to undergo periodic colonoscopies with multiple biopsies staggered along the entire colon.

In cases such as yours, screening with periodic fecal occult blood tests is considered appropriate, but with a higher frequency than that used in screening the general population.

[Effectiveness and costs of screening colonoscopy].

Screening colonoscopy is always indicated when rectosigmoidoscopy reveals an adenoma, since this lesion roughly doubles the patient's risk of contracting colonic cancer. Follow-up should be performed at intervals of about three years after endoscopic removal of all colorectal polyps. Repeated screening examinations are recommended for the following genetic diseases that carry an increased risk of colorectal carcinoma: familial adenomatous polyposis (FAP) and its genetic variant, hereditary non-polyposis colorectal cancer syndrome (HNPCC) and hamartomatous polyposis syndromes (e.g. Peutz-Jeghers). Also in the case of familial "sporadic" carcinoma of the colon, regular screening colonoscopies for first degree relatives are recommended. Although the use of regular screening colonoscopies in patients with a long history of extensive ulcerative colitis is controversial, the recent results support such examinations. While the benefit of screening colonoscopy or sigmoidoscopy of the general population from the age of 50 onward must be affirmed, it should be weighed against the costs involved in such an undertaking. At the present time, the American Cancer Society recommends that from the age of 50 onward, the annual fecal test for occult blood should be supplemented by sigmoidoscopy performed every three to five years.

[Prevention and early detection of colorectal carcinoma by endoscopic examinations].

People at average risk for colorectal cancer (asymptomatic, age > or = 45 years, no risk factors) are offered fecal occult blood testing each year and sigmoidoscopy every five years. In case of a positive fecal occult blood test, examination of the whole colon by colonoscopy should be performed. Colorectal cancer risk is significantly lowered by endoscopic polypectomy in patients with adenomas. After complete removal of adenomatous polyps a control colonoscopy is advised three years after the initial examination. People with a positive family history of colorectal cancer or adenomatous polyps, of inherited polyposis syndromes, of a hereditary non-polyposis colorectal cancer, after polypectomy, after resection of colorectal cancer and with inflammatory bowel disease possess an increased risk for the development of colorectal cancer. Surveillance recommendations in these cases are detailed. In order to increase the cost-benefit ratio in surveillance after curative resection of colorectal cancer the frequency of the surveillance procedures can be reduced. In patients with total or extensive ulcerative colitis colonoscopy with multiple biopsies should be performed after a disease duration of eight to ten years, further recommendations depend on the histopathologic results.

Screening for colorectal cancer and other GI cancers.

Most of the major advances in the screening for gastrointestinal cancers this year were in the area of colorectal cancer screening. Currently, screening is recommended for the prevention of colorectal cancer in average and high-risk populations. For average risk populations, large randomized trials support the use of screening fecal occult blood testing, and case-control studies support the use of screening sigmoidoscopy. This year, several investigators have addressed issues related to the probability of identifying advanced lesions in the proximal colon following a positive screening flexible sigmoidoscopy. Similarly, two studies identified that villous histology in an index polyp was associated with an increased risk of recurrent colonic polyps. Additionally, two large trials provided new insight about the prevalence of mutations in the MLH1 or MSH2 mismatch-repair genes among patients with colorectal cancer. Lastly, a case-control study from Sweden provided the best evidence to date that surveillance colonoscopies for patients with long-standing ulcerative colitis may reduce cancer-related mortality. Although further work is needed, these studies have served to advance our knowledge of colorectal cancer screening substantially.

[Evaluation of various screening and surveillance methods in colorectal carcinoma].

Colorectal cancer is a common disease which is almost wholly preventable by early removal of adenomatous polyps. Screening should be offered to all persons without risk factors from the age of 50. Selection of the appropriate screening programme should take into account personal preference, local expertise and insurance coverage. Endoscopic screening and surveillance investigations should be strongly encouraged in all persons wit risk factors such as (1) previous treatment of colorectal adenomatous polyps or cancers, (2) ulcerative colitis, (3) patients with hereditary colorectal cancer syndromes and (4) first degree relatives of patients with colorectal cancer. The following four strategies are available for candidates > 50 years without risk factors: (1) faecal occult blood testing (annually), (2) flexible sigmoidoscopy (every 5 years), (3) a combination of both (1 + 2) strategies and (4) coloscopy (every 10 years). Coloscopy should be performed after a positive test result in strategy programs 1-3. Results from prospective randomized trials are available only for faecal occult blood testing, showing an approximately 15% reduction of mortality in the screening group. The potential for reduction of colorectal cancer mortality has been estimated at 30-70% and 60-90% for flexible sigmoidoscopy and coloscopy respectively. However, no results from prospective randomized trials are presently available. Cost-effectiveness analysis has not shown relevant differences between the four different screening strategies.

Screening for early colorectal cancer.

There is now solid evidence from randomized trials suggesting that it is possible to reduce mortality from colorectal cancer by 15% to 25% by screening with fecal occult blood tests (FOBTs). The major benefit results from detection of early cancer in average-risk persons above 50 years of age who have a positive test followed by colonoscopy. However, it has to be demonstrated that the same acceptability can be reached in the general population as that obtained in trials. Many countries must establish a screening organization in a limited area to learn how satisfactory quality assurance can be obtained before a country-wide screening program is set up. So far, screening has not resulted in a reduced incidence of colorectal cancer in true population studies despite removal of two to three times as many possible precursors compared to controls. Cost-effectiveness will probably be as good as that known from screening for breast cancer with mammography and better than that for cervical cancer. However, the calculations are based on the unhydrated Hemoccult-II test in randomized trials. More sensitive methods would be attractive, but none has yet been evaluated properly in average-risk persons. There is no general agreement how to screen high risk groups such as patients with previous colorectal adenomas and carcinomas, one or two first-degree relatives with colorectal neoplasia, or ulcerative colitis. Families with familial adenomatous polyposis or hereditary nonpolyposis colorectal cancer, however, are presented with firm guidelines. Genetic screening has been helpful in no more than these two small groups in the colorectal carcinoma universe.

[Screening and early diagnosis of colorectal cancer].

Screening and early diagnosis of colorectal cancer Colorectal cancer, major health problem in industrialised countries, fulfils the conditions required for mass screening. Data from controlled studies indicate that it is possible to reduce colorectal cancer mortality at a population level using faecal occult blood testing. Population-based studies rely on biennial testing in subjects between 50 and 74 and total colonoscopy in case of positive test. The colorectal cancer mortality decrease in this case varies between 15 and 28% in the general population, 33 and 39% among participants to screening. In order to decrease significantly colorectal cancer mortality compliance has to be over 50%. On the basis of available data, the European Commission recommended to organise colorectal cancer screening in the EU. Epidemiological studies allow us to define subjects at high risk for colorectal cancer. Colonoscopy screening is recommended in first degree relatives of patients with colorectal cancer diagnosed before 60 or 65 or with two affected first-degree relatives, in subjects with an extended ulcerative colitis or Crohn disease or with a personal history of large bowel cancer or large adenoma.

[Individual screening for colorectal cancer: which strategy for which patient?].

Currently, more than 4,000 newly colorectal cancer are diagnosed each year in Belgium. The individual average-risk for developing colorectal cancer is about 5%. 90% of colorectal cancer occurred after the age of 50, and in 70% of the cases in patients without particular risk factors (average-risk population). Personal and/or familial history of colorectal adenoma, colorectal cancer, inflammatory bowel disease localised to the colon, familial polyposis syndrome or Hereditary Non Polyposis Colorectal Cancer (HNPCC) increase the risk of colorectal cancer. An individual appropriate screening of high-risk patients and average-risk asymptomatic patients older than 50, together with endoscopic resection of adenoma decrease the incidence and the mortality of colorectal cancer. Usual screening methods are fecal occult blood testing which is not proven to be efficient alone for individual screening (but still recommended for general population's screening), sigmoidoscopy (which has to be completed by a colonoscopy, if lesions founded), and colonoscopy. Virtual colonoscopy and genetic testing need further evaluation. Currently, colonoscopy seems to be the goldstandard method providing complete examination of the whole colon and being the most cost-effective method. Screening strategy should be decided on an individual basis considering the patient's benefit with respect to the informed consent.

[Screening coloscopy: when and how?].

Screening colonoscopy aims at a reduction of colorectal cancer mortality. The efficacy is undetermined due to lack of controlled trials. However, screening colonoscopy is generally accepted in asymptomatic patient with a considerably increased risk for carcinoma in particular in case of familial adenomatous polyposis coli, hereditary nonpolypous colorectal cancer syndrome and adenomas detected by sigmoidoscopy. A positive cost/benefit ratio can also be expected in first-degree relatives of patients with familial sporadic colorectal carcinoma. To date the efficacy of colonoscopic surveillance of patients with extensive ulcerative colitis remains undetermined in spite of an increased risk of cancer in the long-term course. In people with an average risk for colorectal cancer the probability of a development of carcinoma might be reduced by about 45% by once-only sigmoidoscopy performed at the age of 50-60 years. Further reduction can theoretically be expected from routine colonoscopy. However, before a general recommendation can be given, the efficacy must be proved in a randomised controlled trial.

Colorectal cancer

Pathogenic Escherichia coli may increase the risk of colorectal cancer by producing the genotoxic metabolite, colibactin. Inflammatory bowel disease People with inflammatory bowel disease (ulcerative colitis and Crohn's disease) are at increased risk of colon cancer. The risk increases the longer a person has the disease, and the worse the severity of inflammation. In these high risk groups, both prevention with aspirin and regular colonoscopies are recommended. Endoscopic surveillance in this high-risk population may reduce the development of colorectal cancer through early diagnosis and may also reduce the chances of dying from colon cancer. People with inflammatory bowel disease account for less than 2% of colon cancer cases yearly. In those with Crohn's disease, 2% get colorectal cancer after 10 years, 8% after 20 years, and 18% after 30 years. In people who have ulcerative colitis, approximately 16% develop either a cancer precursor or cancer of the colon over 30 years.

Colonoscopy

Fecal occult blood is a quick test which can be done to test for microscopic traces of blood in the stool. A positive test is almost always an indication to do a colonoscopy. In most cases the positive result is just due to hemorrhoids; however, it can also be due to diverticulosis, inflammatory bowel disease (Crohn's disease, ulcerative colitis), colon cancer, or polyps. Colonic polypectomy has become a routine part of colonoscopy, allowing quick and simple removal of polyps during the procedure, without invasive surgery. Colon cancer screening Colonoscopy is one of the colorectal cancer screening tests available to people in the US who are 45 years of age and older. The other screening tests include flexible sigmoidoscopy, double-contrast barium enema, computed tomographic (CT) colongraphy (virtual colonoscopy), guaiac-based fecal occult blood test (gFOBT), fecal immunochemical test (FIT), and multitarget stool DNA screening test (Cologuard).

High prevalence of undetected ulcerative colitis: data from the Nottingham fecal occult blood screening trial.

Inflammatory bowel disease (IBD) is usually diagnosed as a result of symptoms but occasionally is found during investigation for other conditions. An earlier report from Nottingham had found a high prevalence of previously undetected "asymptomatic" IBD detected as a result of colorectal cancer screening, and the aim of this study was to reassess the prevalence, symptoms, and outcome in these patients. We investigated subjects found to be fecal occult blood (FOB) positive in a randomized trial of FOB screening for colorectal cancer. All FOB-positive subjects were investigated by colonoscopy or flexible sigmoidoscopy and barium enema. Subjects with IBD were referred back to their general practitioner for any further investigation and treatment. Seventy-five thousand two hundred fifty-three subjects (aged 45-74) were sent FOB tests and 44,838 (60%) completed a series of tests on one or more occasions. Of 133,000 test series, 1.5% were positive. During investigation 53 cases of previously undetected IBD (52 of ulcerative colitis) were found; 52% (27/52) had proctosigmoiditis only, whereas 25% (13/52) had pancolitis. Only 17% (9/52) were completely asymptomatic, with a half or more reporting some rectal bleeding (54%) or diarrhea (50%). The overall prevalence of undetected ulcerative colitis was 69/10(5) (95% CI = 50-88/10(5)) in people offered screening and 116/10(5) (95% CI = 85-147/10(5)) in people accepting screening and was higher in men. Of 32 subjects followed up 2-12 yr after diagnosis, 91% (29) continued to have few or no symptoms, with only 12 currently receiving any treatment for their colitis. In comparison with detected disease, undetected ulcerative colitis is relatively common but does usually cause some symptoms. It generally appears to follow a benign course, but a significant proportion have extensive colitis and may therefore be at an increased risk of colorectal cancer.

Ulcerative colitis

Colorectal cancer The risk of colorectal cancer is significantly increased in people with ulcerative colitis after ten years if involvement is beyond the splenic flexure. People with backwash ileitis might have an increased risk for colorectal carcinoma. Those people with only proctitis usually have no increased risk. It is recommended that people have screening colonoscopies with random biopsies to look for dysplasia after eight years of disease activity, at one to two year intervals. Mortality People with ulcerative colitis are at similar or perhaps slightly increased overall risk of death compared with the background population. However, the distribution of causes-of-death differs from the general population. Specific risk factors may predict worse outcomes and a higher risk of mortality in people with ulcerative colitis, including: C. difficile infection and cytomegalovirus infection (due to reactivation).

Colorectal cancer

Several screening methods are recommended including stool-based tests every 2 years, sigmoidoscopy every 10 years with fecal immunochemical testing every two years, and colonoscopy every 10 years. It is unclear which of these two methods is better. Colonoscopy may find more cancers in the first part of the colon, but is associated with greater cost and more complications. For people with average risk who have had a high-quality colonoscopy with normal results, the American Gastroenterological Association does not recommend any type of screening in the 10 years following the colonoscopy. For people over 75 or those with a life expectancy of less than 10 years, screening is not recommended. It takes about 10 years after screening for one out of a 1000 people to benefit. The USPSTF list seven potential strategies for screening, with the most important thing being that at least one of these strategies is appropriately used.

Cancer and inflammatory bowel disease: bias, epidemiology, surveillance, and treatment.

Individuals with chronic ulcerative colitis are at increased risk of developing colorectal carcinoma, particularly if there is long-standing disease or extensive colitis. It is generally accepted that the risk of colorectal cancer does not begin until 8 to 10 years after the time of diagnosis of ulcerative colitis. Thereafter it increases by approximately 0.5% to 1.0% per year. In patients with Crohn's disease, the risk of malignancy is smaller and less well defined. The most significant predictor of the risk of malignancy in patients with inflammatory bowel disease is the presence of dysplasia in colonic biopsies. There is considerable controversy in the literature regarding the efficacy of colonoscopic surveillance programs and the role of prophylactic surgery to prevent colorectal cancer. Surveillance certainly fails to detect carcinoma in some patients who are having regular colonoscopy. Concerns have also been raised as to the cost-benefit of colonoscopic surveillance in patients with colitis. Randomized controlled trials of surveillance programs are highly unlikely in view of the low prevalence of IBD in the population, the long period of observation required, and the probability of contamination of surveillance programs by colonoscopy for assessment of disease activity. Despite the lack of clear guidelines, surveillance colonoscopy and biopsy continues to be widely practiced. Research is proceeding to identify genetic and biochemical markers that may prove clinically useful for predicting cancer risk. At present, however, surveillance programs are likely to continue according to institutional practice. It is important for those participating in such programs to be aware of the limitations of colonoscopy and biopsy as a means of reducing the risk of cancer in inflammatory bowel disease.

Evaluation of surveillance programmes for colorectal cancer in ulcerative colitis patients by case-control studies: methodological considerations.

The evaluation of the efficacy of colonoscopy screening in patients with ulcerative colitis for colorectal cancer is associated with methodological difficulties. Case-control studies can, however, be used to determine the efficacy of such a programme and the outline of the methodology in such a programme is presented. The randomised controlled trial provides perspective for case-control studies of screening efficacy. Cases are selected from persons who have ulcerative colitis with manifestations of colorectal cancer: for example, those who have died of colorectal cancer or have symptomatic metastases. Controls are selected from persons who have ulcerative colitis, who had been alive when the case died of colorectal cancer, and who had been subject to the risk of dying from, but had not had, colorectal cancer diagnosed when the case was diagnosed with colorectal cancer. The relevant screening history for cases begins with the case's diagnosis of ulcerative colitis and ends with the cases diagnosis of colorectal cancer; that for controls should be comparable to that for cases to avoid bias. Cases and controls are compared with respect to their "exposure" to colonoscopy during their screening histories: the occurrence of any screening, which took place during the period of time that an occult tumour (or an identifiable lesion) may plausibly have been present. The proposed methodology can evaluate the efficacy of a screening programme rapidly, practically, and ethically.

Colorectal cancer

The three main screening tests are colonoscopy, fecal occult blood testing, and flexible sigmoidoscopy. Of the three, only sigmoidoscopy cannot screen the right side of the colon where 42% of cancers are found. Flexible sigmoidoscopy, however, has the best evidence for decreasing the risk of death from any cause. Fecal occult blood testing (FOBT) of the stool is typically recommended every two years and can be either guaiac-based or immunochemical. If abnormal FOBT results are found, participants are typically referred for a follow-up colonoscopy examination. When done once every 1–2 years, FOBT screening reduces colorectal cancer deaths by 16% and among those participating in screening, colorectal cancer deaths can be reduced up to 23%, although it has not been proven to reduce all-cause mortality. Immunochemical tests are accurate and do not require dietary or medication changes before testing.

Colorectal Cancer Screening and Surveillance in Individuals at Increased Risk.

Individuals at increased risk of developing colorectal cancer include those with a personal or family history of advanced adenomas or colorectal cancer, a personal history of inflammatory bowel disease, or genetic polyposis syndromes. In general, these persons should undergo more frequent or earlier testing than individuals at average risk. Individuals who have a first-degree relative with colorectal cancer or advanced adenoma diagnosed before 60 years of age or two first-degree relatives diagnosed at any age should be advised to start screening colonoscopy at 40 years of age or 10 years younger than the earliest diagnosis in their family, whichever comes first. In individuals with ulcerative colitis or Crohn disease with colonic involvement, colonoscopy should begin eight to 10 years after the onset of symptoms and be repeated every one to three years. Individuals who have a first-degree relative with hereditary nonpolyposis colorectal cancer should begin colonoscopy at 25 years of age and repeat colonoscopy every one to two years. In persons with a family history of adenomatous polyposis syndromes, screening should begin at 10 years of age or in a person's mid-20s, depending on the syndrome; repeat colonoscopy is typically required every one to two years. Screening colonoscopy should begin at eight years of age in individuals with Peutz-Jeghers syndrome. If results are normal, colonoscopy can be repeated at 18 years of age and then every three years. Persons with sessile serrated adenomatous polyposis should begin annual colonoscopy as soon as the diagnosis is established.

Fecal occult blood

Colorectal cancer screening An estimated 1–5% of large tested populations have a positive fecal occult blood test. Of those, about 2–10% have cancer, while 20–30% have adenomas. Screening methods for colon cancer depend on detecting either precancerous changes such as certain kinds of polyps or on finding early and thus more treatable cancer. The extent to which screening procedures reduce the risk of gastrointestinal cancer or deaths depends on the rate of precancerous and cancerous disease in that population. gFOBT (guaiac fecal occult blood test) and flexible sigmoidoscopy screening have each shown benefit. Other colon cancer screening tools such as iFOBT (immunochemical fecal occult blood test) or colonoscopy are also included in guidelines.

Asymptomatic inflammatory bowel disease with special reference to ulcerative colitis in apparently healthy persons.

We examined cases of asymptomatic inflammatory bowel diseases, particularly asymptomatic ulcerative colitis, which were found in apparently healthy Japanese persons who underwent general health screening. Patients with positive immunological fecal occult blood test (IFOBT) among approximately 236,000 persons participating in the health screening program at the Aichi Prefectural Center for Health Care for the past 9 yr underwent total colonoscopy. In patients with ulcerative colitis, we investigated the sex and age distributions, extent of lesion, endoscopic activity, incidence rate, and clinical course. In all, 35 cases of inflammatory bowel disease were detected, and 274 cases of colorectal cancer (not discussed here) were detected in the same population. The 35 cases of inflammatory bowel disease consisted of 19 cases of ulcerative colitis (12 of asymptomatic and minimally symptomatic ulcerative colitis, and seven of symptomatic or with past history of ulcerative colitis); five of intestinal tuberculosis; two of Crohn's disease; two of amebic colitis; and seven of endoscopic colitis. The 12 patients with asymptomatic and minimally symptomatic ulcerative colitis consisted of 11 men and one woman aged 36-63 yr (mean 46.2 yr). We classified these cases into three grades of severity according to endoscopic findings: four cases were mild, eight moderate, and none severe. Of these 12 cases, three were found endoscopically because of positive IFOBT, although barium enema was normal. Anatomic types of colitis cases included three of total colitis, three left-sided colitis, two proctitis, and four right-sided or segmental colitis. In one case, the disease extended proximally during the course of observation. We found 35 cases of inflammatory bowel disease because of positive IFOBT performed as part of a general health screening. Of these, 19 cases were ulcerative colitis. These included many asymptomatic and minimally symptomatic cases, which could be very important in helping to elucidate the natural history of ulcerative colitis; thus, long-term follow up is necessary.

Colorectal polyp

Inflammatory polyp These are polyps that are associated with inflammatory conditions such as ulcerative colitis and Crohn's disease. Prevention Diet and lifestyle are believed to play a large role in whether colorectal polyps form. Studies show there to be a protective link between consumption of cooked green vegetables, brown rice, legumes, and dried fruit and decreased incidence of colorectal polyps. Diagnosis Colorectal polyps can be detected using a faecal occult blood test, flexible sigmoidoscopy, colonoscopy, virtual colonoscopy, digital rectal examination, barium enema or a pill camera. Malignant potential is associated with degree of dysplasia Type of polyp (e.g. villous adenoma): Tubular Adenoma: 5% risk of cancer Tubulovillous adenoma: 20% risk of cancer Villous adenoma: 40% risk of cancer Size of polyp: <1 cm =<1% risk of cancer 1–2 cm=10% risk of cancer >2 cm=50% risk of cancer Normally an adenoma that is greater than 0.5 cm is treated. Gallery

Colorectal cancer

There is tentative evidence for calcium supplementation, but it is not sufficient to make a recommendation. Vitamin D intake and blood levels are associated with a lower risk of colon cancer. Screening As more than 80% of colorectal cancers arise from adenomatous polyps, screening for this cancer is effective for both early detection and for prevention. Diagnosis of cases of colorectal cancer through screening tends to occur 2–3 years before diagnosis of cases with symptoms. Any polyps that are detected can be removed, usually by colonoscopy or sigmoidoscopy, and thus prevent them from turning into cancer. Screening has the potential to reduce colorectal cancer deaths by 60%.

Ulcerative colitis

The risk of cancer arising from a ileal pouch anal anastomosis is low. However, annual surveillance with pouchoscopy may be considered in individuals with risk factors for dysplasia, such as a history of dysplasia or colorectal cancer, a history of PSC, refractory pouchitis, and severely inflamed atrophic pouch mucosa. Bacterial recolonization In a number of randomized clinical trials, probiotics have demonstrated the potential to be helpful in the treatment of ulcerative colitis. Specific types of probiotics such as Escherichia coli Nissle have been shown to induce remission in some people for up to a year. A probiotic called VSL#3 may be effective in inducing remission in active ulcerative colitis, and may be as effective as 5-ASAs in preventing relapse of quiescent UC.

Strategies for detecting colon cancer and/or dysplasia in patients with inflammatory bowel disease.

Patients with longstanding ulcerative colitis and colonic Crohn's disease have an increased risk of colorectal cancer compared with the general population. This review assesses the evidence that endoscopic surveillance may prolong life by allowing earlier detection of colon cancer or its pre-cursor lesion, dysplasia, in patients with inflammatory bowel disease. To assess the effectiveness of cancer surveillance programs in reducing the death rate from colorectal cancer in patients with ulcerative colitis and colonic Crohn's disease. The following strategies were used to identify relevant studies:1. MEDLINE and the Cochrane Central Register of Controlled Trials were searched from 1966 to August 2005. The medical subject headings "Ulcerative Colitis", "Crohn Disease" or "Inflammatory Bowel Disease" and "Surveillance" or "Cancer" were used to perform key-word searches of the databases.2. Hand searching of reference lists from papers. Potentially relevant articles were reviewed independently and unblinded by three authors to determine if they fulfilled the selection criteria. Each article was rated as being eligible, ineligible, or without sufficient information to determine eligibility. Any disagreement between reviewers was resolved by consensus. Any trials published in abstract form were only considered if it was possible to obtain full details of the protocol and results from the authors. Eligible articles were reviewed in duplicate and the results of the primary research trials were abstracted onto specially designed data extraction forms. The proportion of patients dying from bowel cancer or other causes in the control and surveillance groups of each study was derived from life tables, survival curves or where possible, by calculating life tables from the data provided. Data from the original research articles were converted into 2x2 tables (survival versus death x surveillance versus control) for each of the individual studies for comparable follow-up intervals. The presence of significant heterogeneity among studies was tested by the chi-square test. Because this is a relatively insensitive test, a P value of less than 0.1 was considered statistically significant. Provided statistical heterogeneity was not present, the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled relative risk (RR) and 95% confidence intervals as described by Cochrane and Mantel and Haenszel. Karlen 1998a in a nested case-control study comprising 142 patients from a study population of 4664 UC patients, found that 2/40 patients dying of colorectal cancer had undergone surveillance colonoscopy on at least one occasion compared with 18/102 controls (RR 0.28, 95% CI 0.07 to 1.17). One of 40 patients who died from colorectal cancer had undergone surveillance colonoscopies on two or more occasions compared with 12/102 controls (RR 0.22, 95% CI 0.03 to 1.74) in contrast to a more modest effect observed for patients who had only one colonoscopy (RR 0.43, 95% CI 0.05 to 3.76). Choi 1993 found that carcinoma was detected at a significantly earlier stage in the surveilled patients; 15/19 had Duke's A or B carcinoma in the surveilled group compared to 9/22 in the non-surveilled group (P = 0.039). The 5-year survival rate was 77.2% for cancers occurring in the surveillance group and 36.3% for the no-surveillance group (P = 0.026). Four of 19 patients in the surveillance group died from colorectal cancer compared to 11 of 22 patients in the non-surveillance group (RR 0.42, 95% CI 0.16 to 1.11). Lashner 1990 found that four of 91 patients in a surveillance group died from colorectal cancer compared to 2 of 95 patients in a non-surveilled group (RR 2.09, 95% CI 0.39 to 11.12). Colectomy was less common in the surveillance group, 33 compared to 51 (P < 0.05) and was performed four years later (after 10 years of disease) in the surveillance group. For the pooled data analysis 8/110 patients in the surveillance group died from colorectal cancer compared to 13/117 patients in the non-surveillance group (RR 0.81, 95% CI 0.17 to 3.83). There is no clear evidence that surveillance colonoscopy prolongs survival in patients with extensive colitis. There is evidence that cancers tend to be detected at an earlier stage in patients who are undergoing surveillance, and these patients have a correspondingly better prognosis, but lead-time bias could contribute substantially to this apparent benefit. There is indirect evidence that surveillance is likely to be effective at reducing the risk of death from IBD-associated colorectal cancer and indirect evidence that it may be acceptably cost-effective.

Knowledge of colorectal cancer and use of screening tests among higher-risk persons.

Colorectal cancer is a major cause of cancer mortality in the United States, and certain risk factors have been identified. Random samples (N = 893) of residents between 40 and 74 years old in two areas (ie, Long Island, New York and the state of Connecticut) with relatively high rates of colorectal cancer were surveyed by telephone in 1988. Prevalence of certain risk factors for colorectal cancer was estimated, including family history of colorectal cancer and personal history of "ulcerative colitis" and "polyps." Knowledge of dietary risk factors for cancer (ie, cured meat and low fiber intake), daily use of fiber cereals, and frequency of medical checkups did not differ significantly among those in higher-risk groups v other respondents. In multivariate analyses a family history of colorectal cancer was a significant independent predictor of knowledge of the frequency of colorectal cancer relative to stomach cancer, and of ever having heard of a fecal occult blood test, but not of having had an occult blood test or procto(sigmoido)scopy. Persons reporting a history of "ulcerative colitis" had a lower assessment of the curability of colorectal cancer, and the frequency of recent procto(sigmoido)scopic examination was not increased. Findings are discussed with reference to potential educational programs in the primary and secondary prevention of colorectal cancer.

Cancer prevention

Colorectal cancer Colorectal cancer is most often screened with the fecal occult blood test (FOBT). Variants of this test include guaiac-based FOBT (gFOBT), the fecal immunochemical test (FIT), and stool DNA (sDNA) testing. Further testing includes flexible sigmoidoscopy (FS), total colonoscopy (TC), or computed tomography (CT) scans if a TC is non-ideal. A recommended age at which to begin screening is 50 years. However, this is highly dependent on medical history and exposure to CRC risk factors. Effective screening has been shown to reduce CRC incidence by 33% and CRC morality by 43%.

Cancer screening

The US Preventive Services Task Force recommends screening for colorectal cancer using fecal occult blood testing, sigmoidoscopy, or colonoscopy, in adults, beginning at age 50 years and continuing until age 75 years. For people over 75 or those with a life expectancy of less than 10 years screening is not recommended. A new enzyme method for colorectal cancer screening is the M2-PK Test, which is able to detect bleeding and non-bleeding colorectal cancers and polyps. In 2008, Kaiser Permanente Colorado implemented a program that used automated calls and sends fecal immunochemical test kits to patients who are overdue for colorectal cancer screenings. The program has increased the proportion of all eligible members screened by 25 percent. Multi-Target Stool DNA Test (Cologuard) and Plasma SEPT9 DNA Methylation Test (Epi proColon) have been FDA-approved.

Rectal examination

Although the DRE is commonly used as a way to obtain a stool sample for a FOBT (fecal occult blood test) in an office based setting, this is an insufficient way of screening for colorectal cancer and is not recommended. A single office-based FOBT (fecal occult blood test) performed following a digital rectal examination (DRE) is not an adequate screen due to low sensitivity for advanced tumor and colorectal cancer. Screening for colon cancer this way does not meet HEDIS, Medicare or American Cancer Society standards. The FOBT has never been validated for any purpose other than as a take home colon cancer screening test. A paper published in the Journal of General Internal Medicine states, "While FOBT done appropriately (taken home and used according to the instructions) is an important screening option, in-office FOBT may be worse than no screening at all because it misses 95% of cases of advanced tumor, giving many patients a false sense of reassurance."

Fecal occult blood

The American College of Gastroenterology has recommended the abandoning of gFOBT testing as a colorectal cancer screening tool, in favor of the fecal immunochemical test. Though the FIT test is preferred, even the guaiac FOB testing of average risk populations may have been sufficient to reduce the mortality associated with colon cancer by about 25%. With this lower efficacy, it was not always cost-effective to screen a large population with gFOBT. If colon cancer is suspected in an individual (such as in someone with an unexplained anemia), fecal occult blood tests may not be clinically helpful. If a doctor suspects colon cancer, more rigorous investigation is necessary, whether or not the test is positive.

InternalMed_Harrison

540 SCREENING The rationale for colorectal cancer screening programs is that the removal of adenomatous polyps will prevent colorectal cancer, and that earlier detection of localized, superficial cancers in asymptomatic individuals will increase the surgical cure rate. Such screening programs are particularly important for individuals with a family history of the disease in first-degree relatives. The relative risk for developing colorectal cancer increases to 1.75 in such individuals and may be even higher if the relative was afflicted before age 60. The prior use of proctosigmoidoscopy as a screening tool was based on the observation that 60% of early lesions are located in the rectosigmoid. For unexplained reasons, however, the proportion of large-bowel cancers arising in the rectum has been decreasing during the past several decades, with a corresponding increase in the proportion of cancers in the more proximal descending colon. As such, the potential for proctosigmoidoscopy to

Colorectal cancer

Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel movements, weight loss, and fatigue. Most colorectal cancers are due to old age and lifestyle factors, with only a small number of cases due to underlying genetic disorders. Risk factors include diet, obesity, smoking, and lack of physical activity. Dietary factors that increase the risk include red meat, processed meat, and alcohol. Another risk factor is inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis. Some of the inherited genetic disorders that can cause colorectal cancer include familial adenomatous polyposis and hereditary non-polyposis colon cancer; however, these represent less than 5% of cases. It typically starts as a benign tumor, often in the form of a polyp, which over time becomes cancerous.

Wendy Atkin

From 1994 she worked with Jane Wardle on a trial of flexible sigmoidoscopy that included endoscopic examination of the colon, reporting that 40% of colorectal cancers could be prevented by this intervention. She compared the screening to a Faecal occult blood (FOB) test. In 2008 she moved to St Mary's Hospital, London, where she established the Cancer Screening and Prevention Research Group. The group researches bowel cancer and, ultimately, aims to reduce the number of people who die from the disease. Their 2010 paper outlining the results of the UK Flexible Sigmoidoscopy Screening Trial was the most frequently cited paper in The Lancet that year. The landmark study was a randomised controlled trial of almost 400,000 adults across 14 areas in the UK. If there were any polyps, people were referred for a colonoscopy. The strategy was rolled out by the UK National Screening Committee in 2011 and was expected to achieved complete population coverage in 2016. This was achieved with a £60

Colonoscopy

Medicare coverage In the United States, Medicare insurance covers the following colorectal-cancer screening tests: Colonoscopy: average risk — every 10 years beginning at age 50, high risk — every 2 years with no age restriction Flexible sigmoidoscopy — every 4 years beginning at age 50 Double-contrast barium enema: average risk — every 4 years beginning at age 50, high risk — every 2 years (CT) colongraphy: not covered by Medicare gFOBT: average risk — every year beginning at age 50 FIT: average risk — every year beginning at age 50 Cologuard: average risk — every 3 years beginning at age 50 Risks About 1 in 200 people who undergo a colonoscopy experience a serious complication. Perforation of the colon occurs in about 1 in 2000 procedures, bleeding in 2.6 per 1000, and death in 3 per 100,000, with an overall risk of serious complications of 0.35%.