Is the type of test used for mass colorectal cancer screening a determinant of compliance? A cluster-randomized controlled trial comparing fecal occult blood testing with flexible sigmoidoscopy

BACKGROUND: The efficacy of colorectal cancer screening has been proved, and three different screening tests are recommended by international guidelines: the faecal occult blood test, flexible sigmoidoscopy and colonoscopy. While the effectiveness of a screening program depends on the compliance obtained, the role of the type of test on compliance has not yet been sufficiently studied. Aims: To measure the effect of the type of screening test used, i.e. faecal occult blood test or flexible sigmoidoscopy, on the compliance to colorectal cancer screening programs. SUBJECTS AND METHODS: A cluster-randomized two-arm trial was conducted. We randomly assigned 20 GP's practices that had an average of 150 patients between 50 and 74 years old. RESULTS: 1449 individuals were referred to faecal occult blood test and 1538 to flexible sigmoidoscopy. The faecal occult blood test obtained higher compliance: 17.2% (95%CI 12.5-25.7) versus 7.0% (95%CI 5.7-9.0). The socio-economic status was an effect modifier of the test type: the effect of the type of test was smaller in low socioeconomic classes. CONCLUSIONS: The type of screening test used for colorectal cancer is a determinant of participation. In a low compliance area, better compliance will result from offering the faecal occult blood test than from the flexible sigmoidoscopy.     

Excellent performance of Hemoccult Sensa in organised colorectal cancer screening

BackgroundFaecal occult blood (FOB) testing is the most commonly chosen approach in organised population-based colorectal cancer screening programmes throughout the world. Several FOB tests are available which differ in their test qualities. While immunological tests are gaining popularity due to their lower labour intensive analysis and higher standardisation, they are heat labile and more expensive. We studied the real-life experience of a large population-based, organised, screening programme in Israel which employs FOB testing with Hemoccult Sensa, a guaiac test with increased sensitivity that is similar to that of the immunological tests for cancer.MethodsClalit Health Services is the largest health care provider in Israel. All eligible insurees are actively invited to perform a free-of-charge, home-based, faecal occult blood test, using Hemoccult Sensa. All tests with positive results are followed up and information on colonoscopy, surgical procedures and pathology findings is collected.ResultsDuring an 18 month period (July 2007–December 2008) 382,792 FOBT tests (in 325,851 people) were performed by the target population, of them 85% Jews and 15% Arabs. Seven hundred and eighteen colorectal cancers and 2652 adenomas were detected. The overall test positivity rate in repeatedly-tested people was 4.2%. The overall detection rate of colorectal cancer in the subsequent tests was 1.7/1000 reflecting 91% of the expected period-incidence of CRC. 70% of the cancers were detected at stages Duke’s B2 and lower. Left-sided cancers were detected at a significantly better stage than right-sided cancers (P < 0.001). Detection rates among Arabs were somewhat lower than among Jews but the screening programme led to a meaningful increase in national incidence rate in this subgroup by detecting tumours that were otherwise asymptomatic.ConclusionThe Clalit organised colorectal cancer screening programme, using low cost Hemoccult Sensa, has reached the targets of very high detection rate of cancers, most of them at low stage while keeping a low positivity rate. This approach demonstrates an efficient field-tested alternative to other, more costly, screening options.     

Relationships between a sign of rectal bleeding and the results of an immunochemical occult blood test, and colorectal cancer.

A cross-sectional study based on medical check-up was carried out to investigate the association between signs of rectal bleeding and colorectal cancer, and the results of an immunochemical faecal occult blood test. The 9625 patients received both an immunochemical faecal occult blood test using a two-consecutive-day method and colonoscopy. They were then divided into two groups, according to the results of a self-completed questionnaire on the signs of rectal bleeding. The positivity rate of the immunochemical faecal occult blood test as well as the positive predictive value for colorectal cancer were determined in these two groups. The faecal occult blood test was positive in 9.3% of patients with rectal bleeding and in 4.4% of patients without rectal bleeding, and the positive predictive value for colorectal cancer was 0.79 and 0.27 in patients with and without rectal bleeding, respectively. This indicates a significant difference in the positivity rate (P < 0.001) as well as the positive predictive value (P < 0.05) between these two groups. The results suggest that there are positive associations between the signs of rectal bleeding and the results of immunochemical faecal occult blood test, and between the patients presenting with rectal bleeding and colorectal cancer.     

Screening for colorectal cancer in Uruguay with an immunochemical faecal occult blood test.

An observational prospective study was carried out in Uruguay to evaluate the feasibility of colorectal cancer screening using immunochemical faecal occult blood tests with no dietary restrictions in an average-risk population. An automated system was used for processing the samples with a cut-off haemoglobin level of 100 ng/ml. Of the 11,734 study participants who received an immunochemical test kit (OC-Hemodia), 10,573 (90.1%) returned samples for screening. The results of 1170 (11.1%) of the responders were positive. Subsequently, colonoscopy was performed on 879 (75.1%) of the participants with a positive test result and showed neoplasia in 330 participants. Fifty four had advanced cancer, 47 had early cancer, 131 had high-risk adenoma and 98 had low-risk adenoma. The detection rates and the positive predictive values were 0.95 and 8.6% for cancer, and 1.24 and 11.2% for high-risk adenoma, respectively. The high compliance and high detection rates for cancer and high-risk adenoma achieved in the colorectal cancer screening programme verifies the feasibility of an immunochemical faecal occult blood test in screening an average-risk population in Uruguay, a country with a small population, but with high morbidity and mortality rates for this disease.     

Overview of Colorectal Cancer Screening in the United States

Abstract

Because colorectal cancer is the second leading cause of cancer-related death in the United States, the disease meets the requirements of the World Health Organization for screening. In most instances, development of adenocarcinoma is preceded by a noninvasive adenomatous (dysplastic) phase that can be identified endoscopically or radiographically at the time of screening. Currently, four screening tests are in use: the fecal occult blood test, flexible sigmoidoscopy, the double contrast barium enema, and colonoscopy. A significant impediment to optimal screening is a low rate of use in the general population despite evidence that colorectal cancer is preventable and curable when detected early.     

Interval cancers in a community-based programme of colorectal cancer screening with faecal occult blood test.

Interval cancers represent the major limitation of screening for colorectal cancer with the faecal occult blood test. The aim of this study was to describe the characteristics of interval cancers and the sensitivity of the screening programme in a well-defined French population. During five screening rounds, 398 cancers were diagnosed in those of the population having performed at least one screening test; 57.8% of them were interval cancers. The proportion of interval cancers was higher among cancers of the rectal ampulla (72.2%) than among cancers of other sites (52.9%) (P < 0.001). The proportion of TNM stage I and II were higher among screen-detected cancers (73.8%) than among interval cancers (57.4%). The overall sensitivity of the screening programme was 62.9% within 1 year, and 48.7% within 2 years. An improvement in the sensitivity of the faecal occult blood test for colorectal cancer screening is needed, without an unacceptable loss of specificity.     

上海市社区居民大肠癌筛查便隐血检测效果分析

背景与目的：上海市为符合条件的居民提供免费的大肠癌筛查服务,通过对上海市居民大肠癌筛查中两次便隐血检测和后续诊断检查结果的分析,评价筛查中两次便隐血检测的效果,为基于人群的疾病筛查项目提供科学依据。方法：筛查的目标人群为50~74岁的上海居民,使用两次免疫法便隐血检测和危险度评估为初筛,初筛阳性者进行肠镜检查。结果：筛查期间,共有809 528人完成了两次便隐血检测,便隐血检测阳性者共有104 953人,其中第一次阳性的人数为47 421人,阳性率为5.9%,第二次阳性的人数为36 462人,阳性率为4.5%,两次阳性的人数为21 070人,阳性率为2.6%。便隐血检测阳性的筛查对象中,有49 339人接受了肠镜检查,肠镜检查顺应性为47.0%。两次阳性的筛查对象的肠镜参与率明显高于单次阳性的筛查对象（P<0.001）。在所有筛查出的大肠癌和癌前期病变中,仅进行一次便隐血检测可以诊断出大肠癌1 200例,占79.5%;发现癌前期病变3 777例,占68.1%。进行第二次便隐血检测可以多诊断出大肠癌310例,占20.5%;发现癌前期病变1 767例,占31.9%。结论：相比于单次便隐血检测, 进行两次便隐血检测的初筛可以更有效地检测出阳性对象,两次便隐血检测可提高后续肠镜检查的参与率,所检出的大肠癌和癌前期病变数量也均有所提高且增量成本较低。因此建议在以人群为基础的大肠癌筛查中采用两次或更多次数的便隐血检测,以提高筛查效率。     

Risk of perforation after colonoscopy and sigmoidoscopy: a population-based study

BACKGROUND: Although the risk of bowel perforation is often cited as a major factor in the choice between colonoscopy and sigmoidoscopy for colorectal screening, good estimates of the absolute and relative risks of perforation are lacking. METHODS: We used a large population-based cohort that consisted of a random sample of 5% of Medicare beneficiaries living in regions of the United States covered by the Surveillance, Epidemiology, and End Results (SEER) Program registries to determine rates of perforation in people aged 65 years and older. We identified individuals who were cancer-free and had undergone colonoscopy or sigmoidoscopy between 1991 and 1998, calculated both the incidence and risk of perforation within 7 days of the procedure, and explored the impact on incidence and risk of perforation of age, race/ethnicity, sex, comorbidities, and indication for the procedure. We also estimated the risk of death after perforation. Risks were calculated with odds ratios (ORs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: There were 77 perforations after 39 286 colonoscopies (incidence = 1.96/1000 procedures) and 31 perforations after 35 298 sigmoidoscopies (incidence = 0.88/1000 procedures). After adjustment, the OR for perforation from colonoscopy relative to perforation from sigmoidoscopy was 1.8 (95% CI = 1.2 to 2.8). Risk of perforation from either procedure increased in association with increasing age (P(trend)<.001 for both procedures) and the presence of two or more comorbidities (P(trend)<.001 for colonoscopy and P(trend) =.03 for sigmoidoscopy). Compared with those who were endoscopied and did not have a perforation, the risk of death was statistically significantly increased for those who had a perforation after either colonoscopy (OR = 9.0, 95% CI = 3.0 to 27.3) or sigmoidoscopy (OR = 8.8, 95% CI = 1.6 to 48.5). The risk of perforation after colonoscopy, especially for screening procedures, declined during the 8-year study period. CONCLUSIONS: The risk of perforation after colonoscopy is approximately double that after sigmoidoscopy, but this difference appears to be decreasing. These observations should be useful to clinicians making screening and diagnostic decisions for individual patients and to policy officials setting guidelines for colorectal cancer screening programs.     

Evaluation of the accuracy of serum MMP-9 as a test for colorectal cancer in a primary care population

Background  

Bowel cancer is common and is a major cause of death. Meta-analysis of randomised controlled trials estimates that screening for colorectal cancer using faecal occult blood (FOB) test reduces mortality from colorectal cancer by 16%. However, FOB testing has a low positive predictive value, with associated unnecessary cost, risk and anxiety from subsequent investigation, and is unacceptable to a proportion of the target population. Increased levels of an enzyme called matrix metalloproteinase 9 (MMP-9) have been found to be associated with colorectal cancer, and this can be measured from a blood sample. Serum MMP-9 is potentially an accurate, low risk and cost-effective population screening tool. This study aims to evaluate the accuracy of serum MMP-9 as a test for colorectal cancer in a primary care population.     

Colorectal cancer screening with the addition of flexible sigmoidoscopy to guaiac-based faecal occult blood testing: A French population-based controlled study (Wintzenheim trial)

ObjectiveTo assess the feasibility, participation and neoplasia yield of adding a flexible sigmoidoscopy (FS) once in a lifetime to a colorectal cancer screening programme with guaiac-based faecal occult blood test (gFOBT).MethodsA total of 4771 average risk residents aged 50–74 of a canton of the Haut-Rhin, a French administrative area, were invited every other year to participate in an organised screening programme with gFOBT. Of them, those aged 55–64 (1824 people) were, in addition, invited once by mail to visit their general practitioner (GP) for a screening with FS performed by a gastroenterologist.ResultsIn all, 2717 people (56.9%) (95% confidence interval (CI) 55.5–58.4) were screened with one or other of the two tests or with both tests. Compliance was 56.7% (55.3–58.1) with gFOBT and 20.9% (19.1–22.8) with FS. Both tests were performed by 20.2% (18.4–22.1) of people. Compliance with FS was 1.9% in people who had not complied with gFOBT and 31.9% in people who complied. The latter was ?50% in patients of 26 motivated GPs. The detection rate for advanced neoplasia was 17.7 per 1000 people screened (12.7–22.6) with the combined procedure, more than three times higher than that with gFOBT alone.ConclusionA population-based screening programme with the addition of FS to gFOBT is feasible and safe through an organisation involving GPs. The performances of the two screening tools are complementary: high compliance – low yield for gFOBT and vice versa for FS. The addition of a single FS screening in people aged 55–64 to an organised programme with biennial gFOBT in people aged 50–74 is a colorectal cancer screening option that deserves further exploration.     

Screening colonoscopy before prostate cancer treatment can detect colorectal cancers in asymptomatic patients and reduce the rate of complications after brachytherapy

PurposeTo investigate the incidence of undiagnosed, asymptomatic synchronous colorectal cancer (CRC) by using screening colonoscopy before brachytherapy, and to compare the subsequent rates of CRC and rectal toxicity in this screened population with those rates in unscreened patients after brachytherapy.Methods and MaterialsPatient, disease, and treatment characteristics, including history of colonoscopy and CR malignancy, were extracted from the medical records of all men who had undergone brachytherapy as monotherapy for low- or intermediate-risk prostate cancer at a single tertiary cancer care center between January 2000 and December 2009. The frequency of biopsy or polypectomy at screening colonoscopy, incidence of CR malignancy before and after prostate cancer diagnosis, and rate of brachytherapy toxicity including rectal bleeding were compared between men who had had screening colonoscopy before brachytherapy and men who had not.ResultsOf the 451 men identified, 268 had undergone screening colonoscopy during the 36 months before brachytherapy and 183 had not. Of the 268 men who had had screening colonoscopy, 117 (44%) underwent biopsy or polypectomy, and 6 (3.2%) were found to have asymptomatic CRC. After brachytherapy, CRC was diagnosed in 3 (1.6%) of the 183 men who had not had screening colonoscopy before treatment versus 0 of the 268 men who had had screening colonoscopy (P = 0.035). Rectal toxicity was more common and more severe among men who had not undergone screening colonoscopy compared with those who had had screening colonoscopy before brachytherapy (14% vs 6%, P = 0.003). More unscreened patients (18% vs 5%) underwent postbrachytherapy colonoscopy (P < 0.001), with the potential of subjecting the irradiated rectum to biopsy.ConclusionsMore than 3% of men with newly diagnosed prostate cancer in this study presented with undiagnosed, asymptomatic CRC, and the rate of postbrachytherapy rectal complications was higher among unscreened than among screened patients. We recommend screening colonoscopy for men who have not had CRC screening within the 3 years preceding prostate cancer diagnosis before radiation therapy to avoid unnecessary rectal biopsies and the associated risk of major complications.     

A pilot study of participation in faecal occult blood testing and screening colonoscopy after health education in Hong Kong.

Colorectal cancer is the second commonest cancer in Hong Kong. The screening behaviour of the Chinese population has not been assessed. The aim of this study is to report a pilot study of educating and subsequent evaluation of colorectal cancer screening behaviour in the Hong Kong Chinese population. Subjects were invited to attend a free health talk on colorectal cancer. Both self-paid faecal occult blood testing (FOBT) and free screening colonoscopy were offered after the education programme. Of the participants taking part in the education programme 113/119 (95%) completed the FOBT. Of the FOBT 8/113 (7%) showed positive result and three patients had neoplasia at colonoscopy. Twenty-five patients with negative FOBT also completed colonoscopy; two had adenomas. Screening colonoscopy after FOBT was accepted by 28% of subjects. Those younger than 65 years and those with a positive FOBT (7/8 versus 25/105 for those with negative FOBT, P=0.0003) were more likely to agree to screening colonoscopy. In conclusion, health education is important for ensuring high acceptance and implementation of colorectal cancer screening in Hong Kong Chinese. FOBT is an acceptable and feasible screening method in Hong Kong.     

Use of faecal markers in screening for colorectal neoplasia: a European group on tumor markers position paper

Several randomized controlled trials have shown that population‐based screening using faecal occult blood testing (FOBT) can reduce mortality from colorectal neoplasia. Based on this evidence, a number of countries have introduced screening for colorectal cancer (CRC) and high‐risk adenoma and many others are considering its introduction. The aim of this article is to critically review the current status of faecal markers as population‐based screening tests for these neoplasia. Most of the available faecal tests involve the measurement of either occult blood or a panel of DNA markers. Occult blood may be measured using either the guaiac faecal occult blood test (gFOBT) or a faecal immunochemical test (iFOBT). Although iFOBT may require a greater initial investment, they have several advantages over gFOBT, including greater analytical sensitivity and specificity. Their use results in improved clinical performance and higher uptake rates. Importantly for population screening, some of the iFOBTs can be automated and provide an adjustable cutoff for faecal haemoglobin concentration. However, samples for iFOBT, may be less stable after collection than for gFOBT. For new centres undertaking FOBT for colorectal neoplasia, the European Group on Tumour Markers recommends use of a quantitative iFOBT with an adjustable cutoff point and high throughput analysis. All participants with positive FOBT results should be offered colonoscopy. The panel recommends further research into increasing the stability of iFOBT and the development of improved and affordable DNA and proteomic‐based tests, which reduce current false negative rates, simplify sample transport and enable automated analysis.     

2006～2015年中国大肠癌筛查人群依从性的Meta分析

[目的]系统评价中国大肠癌筛查人群的依从性,为开展相关预防与控制工作提供基础数据.[方法]计算机检索中国生物医学文献数据库(光盘版)、中文期刊全文数据库(光盘版)、万方电子期刊、PubMed、EBSCO等数据库,并辅以参考文献追溯和手工检索方法,查找大肠癌初筛人群数量在5000～300 000人的研究文献,且采用的筛查方法为问卷调查与大便潜血检测(FOBT)进行初筛,发现高危人群再接受肠镜检查.检索时限为建库时间至2016年6月.由2位评价员按照纳入与排除标准独立筛选文献、提取资料和评价纳入研究的方法学质量后,采用R3.3.1软件进行Meta分析.[结果]最终纳入25篇文献,共827 904人接受初筛.Meta分析结果显示,问卷调查、FOBT、肠镜的依从率分别为56％ (95％CI:40％～72％,P＜0.0001)、50％ (95％CI:33％～67％,P＜0.0001)、44％ (95％CI:33％～56％,P＜0.0001).对肠镜依从率分层分析发现,农村地区肠镜依从率为64％(95％CI:52％～75％,P＜0.0001),高于城市地区33％ (95％CI:22％～45％,P＜0.0001);北方为44％(95％CI:27％～70％,P＜0.0001),略高于南方42％(95％CI:29％～55％,P＜0.0001);初筛人数≥10 000人的大样本研究依从率为49％(95％CI:34％～64％,P＜0.0001),高于小样本研究的35％(95％CI:16％～57％,P＜0.0001);与职工体检结合的大肠癌伺机性筛查的肠镜依从率为83％(95％CI:32％～98％,P＜0.0001),高于一般社区人群筛查的40％ (95％CI:29％～52％,P＜0.0001).[结论]中国大肠癌筛查人群依从性较低,因此需从筛查方式的选择、筛查流程设计、筛查过程的质量控制、健康宣传等多方面入手提高依从性.     

Faecal occult blood screening and reduction of colorectal cancer mortality: a case-control study

To estimate the efficacy of screening on colorectal cancer mortality, a population-based case-control study was conducted in well-defined areas of Burgundy (France). Screening by faecal occult blood test prior to diagnosis in cases born between 1914 and 1943 and who died of colorectal cancer diagnosed in 1988-94 was compared with screening in controls matched with the case for age, sex and place of residence. Cases were less likely to have been screened than controls, with an odds ratio (OR) of 0.67 [95% confidence interval (CI) 0.48-0.94]. The negative overall association did not differ by gender or by anatomical location. The odds ratio of death from colorectal cancer was 0.64 (95% CI 0.46-0.91) for those screened within 3 years of case diagnosis compared with those not screened. It was 1.14 (95% CI 0.50-2.63) for those screened more than 3 years before case diagnosis. There was a negative association between the risk of death from colorectal cancer and the number of participations in the screening campaigns. The inverse association between screening for faecal occult blood and fatal colorectal cancer suggests that screening can reduce colorectal cancer mortality. This report further supports recommendations for population-based mass screening with faecal occult blood test.     

反向被动血凝法检测粪便潜血对大肠癌人群筛检的效果评价

Evaluation of reverse passive hemagglutination (RPHA) fecal occult blood (FOB) test in screening for colorectal cancer was carried out in a group of subjects (3034 persons) with history of rectal polyp and ulcer. All subjects were examined by 60 cm fiberoptic colonoscopy, RPHA and benzidine (BT) FOB tests. Among this high risk population, 10 cases of colorectal cancer and 1 case of rectal carcinoid were detected by colonoscopy and pathology. Regarding the findings under fiberoptic colonoscopy as a reference standard, the sensitivity of RPHA and BT in screening for colorectal cancer was 63.6% and 72.7%; the specificity was 81.9% and 61.7%; the general indicator--Youden index was 0.46 and 0.34, respectively. In 7 cases of colorectal cancer with both FOB tests positive, 5 (71%) had lesions in early stages (Dukes A and B). The results indicate that comparing with BT, RPHA has slightly lower sensitivity but higher specificity. RPHA fecal occult blood test could be used as preliminary screening for colorectal cancer.     

Effect of faecal occult blood testing on colorectal mortality: Results of a population-based case-control study in the district of Florence,Italy

The aim of our case-control study was to estimate the effect on mortality from colorectal cancer (CRC) of a population-based screening with a faecal occult blood test started in 1982 in a rural area of the district of Florence. We examined the relationship between mortality and the interval since the most recent screening. The cases in the study were 206 individuals who had died from CRC after the age of 41 years. Five controls were selected randomly from the list of individuals alive at the time of diagnosis of the corresponding case and were matched by sex, age and place and length of residence. After adjustment for potentially confounding factors, the odds ratio (OR) for death from CRC for screened persons vs. those not screened was 0.60 [95% confidence interval (CI), 0.4–0.9]. The OR was lowest in the first 3 years after the most recent test (OR = 0.54; 95% CI, 0.3–0.9) and increased towards unity subsequently. Our results suggest that screening for CRC by biennial faecal occult blood testing can reduce mortality from the disease. Int. J. Cancer 73:208–210, 1997. © 1997 Wiley-Liss, Inc.     

A cost-effective analysis of the optimum number of stool specimens collected for immunochemical occult blood screening for colorectal cancer

This study was carried out to assess, from the viewpoint of cost-effectiveness, the optimum number of faecal specimens to collect for use in immunochemical occult blood testing as a means of screening for colorectal cancer. 3300 asymptomatic individuals were subjects of this study. They gave samples for an immunochemical faecal occult blood test, monohaem and colonoscopy was carried out during a medical check-up. For evaluation of the optimum number of sampling specimens, the results of the first day of sampling, those of the first and second days, and those of samples taken for 3 consecutive days were considered as the single-day method, the 2-day method and the 3-day method respectively. The average cost to detect 1 patient with colorectal cancer, the detection rate and the false-positive rate of these three faecal sample collection methods were evaluated. The average costs for one cancer case detected were calculated as $3,630.68 for the single-day method, $3,350.65 for the 2-day method and $4,136.36 for the 3-day method, respectively. The detection rate and the false-positive rate were calculated as 47 and 3.5% for the single-day method, 82 and 4.7% for the 2-day method and 88 and 5.3% for the 3-day method, respectively. This detection rate was significantly different between the single- and the 2-day methods, as well as between the single- and the 3-day methods (P<0. 05). No significant differences in the false-positive rate amongst the three testing methods were observed. This analysis suggests that a 2-day faecal collection method is recommended for immunochemical occult blood screening by Monohaem from the aspects of cost-effectiveness and diagnostic accuracy.     

Diagnostic yield of a one sample immunochemical test at different cut-off values in an organised screening programme for colorectal cancer

BackgroundQuantitative immunochemical faecal occult blood tests have become the recommended tests for colorectal cancer screening. The aim of this study was to complete our knowledge on the performance of one of the quantitative immunochemical tests available, FOB-Gold, and to propose a possible strategy for an organised screening programme.Patients and methodsWithin the French organised screening programme, 23,231 average-risk individuals, aged 50–74 performed both a 3-day Hemoccult test and a 1-day FOB-Gold test. Performances of the immunochemical test were evaluated at different cut-off levels.ResultsThe positivity rate for the Hemoccult was 2.1% and for the FOB-Gold varied between 4.6% (cut-off value of 100 ng/mL, the lowest studied cut-off) and 2.1% (cut-off value of 352 ng/mL). The number of colonoscopies decreased with increasing cut-off values by 21.5% (150 ng/mL), 35.4% (200 ng/mL) and 53.3% (352 ng/mL). The corresponding miss rate for CRC was respectively 6.4%, 11.1% and 22.2%, and for advanced adenoma respectively 16.3%, 29.2% and 43.6%. Compared with the reference cut-off for the FOB-Gold (100 ng/mL) the miss rate for Hemoccult was 53% for CRC and 77% for advanced adenoma.ConclusionThe study suggests that in countries with colonoscopy facilities compatible with a screening test positivity rate of up to 5%, use of a 1-day test with a cut-off value between 100 and 150 ng/mL could be the recommended strategy. Further increasing the cut-off value up to the same positivity rate as Hemoccult could be used in areas with limited access to colonoscopy.     

Facteurs psychologiques d’adhésion au dépistage du cancer colorectal par le test Hémoccult® II

In French people aged over 50 years, colorectal cancer is a major cause of morbidity and mortality. For an asymptomatic population at average risk of developing this somatic disease, the test usually used is the Hemoccult II® Test, which can detect the presence of occult blood in the stool. It is clear that using this test remains today below the recommended standards despite health campaigns that encourage efficient use. Several practical reasons and socio-economic obstacles can be invoked to explain these findings. Anyway, the doctor’s recommendations against screening for colorectal cancer seem to be decisive. But fear and embarrassment may deter some patients from talking openly with their doctors about colorectal cancer and its screening. The possible role of these disturbing emotions in the adoption of cancer screening has been the subject of a growing number of researches over the past thirty years. But, it still remains very unclear whether anxiety inhibits or motivates colorectal cancer screening. To promote equal access to it, we think it is important to better describe the psychological attitudes displayed toward it, to maximize the impact of campaigns that recommend the use of the Hemoccult II® test.