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Background & Aims: Several randomized population-based studies have shown that screening for colorectal cancer (CRC) by fecal occult blood tests (FOBTs) can reduce CRC mortality. The aim of this French population-based study was to assess whether a similar benefit could be obtained in countries characterized by high performances in the diagnosis and management of CRC., Methods: Small-sized geographic areas, including 91,199 individuals aged 45-74 years, were allocated to either FOBT screening or no screening. Six screening rounds were performed. The FOBT was performed without diet restriction and was sent to a central analysis center and processed without rehydration. Screening group participants who had a positive test result were offered a full colonoscopy. The entire population was followed up for 11 years after study entry., Results: Acceptability of the test was 52.8% at the first screening round and varied between 53.8% and 58.3% in the successive rounds. Positivity rates were 2.1% initially and 1.4% on average in the successive rounds. CRC mortality was significantly lower in the screening population compared with the control population (mortality ratio, 0.84; 95% confidence interval, 0.71-0.99). The reduction in CRC mortality was more pronounced in those who participated at least once (mortality ratio, 0.67; 95% confidence interval, 0.56-0.81)., Conclusions: Our findings, together with the results of other trials, suggest that biennial screening by FOBTs can reduce CRC mortality regardless of the quality of the health system and support attempts to introduce large-scale screening programs into the general population.

Objectives: The aim of this population-based study was to specify the positivity rate, the positive predictive value of Hemoccult test as well as the characteristics of the cancers and adenomas screened during the successive colorectal cancer screening campaigns., Methods: This study focused on five colorectal cancer mass screening campaigns by Hemoccult test carried out between 1988 and 1996. The test was offered every two years to a cohort of subjects born between 1914 and 1943 and living in some districts of the Saône-et-Loire administrative area., Results: The positivity rate of the test was higher in the first campaign (2.1%) than in the subsequent ones (mean 1.3%). It was also higher in males than in females and it increased with age. After a positive test, 85.4% of the subjects had a colonic exploration. The exploration rate was higher when the test was offered by general practitioners (88.0%) than when it was mailed (77.8%) (P < 0.01). Through this test, cancer was detected in 168 patients, and one adenoma or more in 414 patients. The positive predictive value was 11.4% for cancer, 17.1% for adenoma > or = 1 cm and 11.1 for adenoma < 1 cm. It was higher in males than in females and it increased with age. Depending on the campaigns, 35.9% to 47.3% of the subjects explored after a positive test had a cancer or an adenoma. The screened cancers or adenomas were more often localized in the sigmoid or the rectum. Three quarters of screened cancers were stage I or II (TNM classification). All together, 82.7% of cancers were treated with surgical resection for cure and 10.1% with endoscopic resection., Conclusions: This work confirms the feasibility of carrying out regular colorectal cancer screening campaigns, through which a few subjects can be selected for undergoing colonic explorations. These latter can detect a cancer or adenoma in 40% of cases.

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.

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.

Our aim was to study the relationship between the level of positivity of the Hemoccult colorectal cancer screening test and the positive predictive value on one hand, and the characteristics of the screened neoplasms on the other. This study focuses on four successive colorectal cancer screening campaigns in a population of 45,642 subjects born between 1914 and 1943. There were 1 or 2 positive slides in 50.1% of cases, 3 or 4 in 30.7% of cases and 5 or 6 in 19.2% of cases. The positive predictive value was 11.1% for cancer, 17.4% for adenoma > or = at 1 cm and 10.1% for adenoma < 1 cm. For a cancer or adenoma > or = at 1 cm, the positive predictive value varied between 18.6% when there were 1 or 2 positive slides, and 52.5% when there were 5 or 6 positive slides. Dukes A cancers are less likely to have 5 or 6 positive slides than more advanced cancers. On the contrary, neither cancer localisation nor characteristics of adenomas > or = at 1 cm (localisation, size, degree of dysplasia) influenced the number of positive slides. Owing to intermittent colorectal cancer bleeding, it seems necessary to take several successive samples. Two samples per stool over three successive stools seem like a good compromise. The informative value of the test increases with the number of positive slides.

Objective: To evaluate the influence on compliance of demographic variables and of the way of proposing a faecal occult blood test in a colorectal cancer mass screening programme., Setting: Well defined population in Burgundy (France)., Methods: From 1988 to 1996 five screening rounds were conducted in people aged 45 to 74 on entering the study. The screening test was provided free of charge by primary care physicians over a four month period, then mailed to non-consultants, followed by a potential reminder letter. The whole population was invited to participate in each screening campaign., Results: During the five successive rounds, compliance was 52.8%, 54.0%, 57.3%, 58.3%, and 56.2%. It was higher in women than in men, in those initially aged 50 to 69 than in the extreme age groups, and in urban than in rural areas. Overall, 68.7% of the invited population completed at least one screening test and 37.2% completed the five rounds. Among those who participated once in a screening campaign, between 79.6% and 87.6% participated in the succeeding ones. Compliance was higher when the test was proposed by GPs (varying between 85.2% and 94.0% according to the screening campaign) than when it was sent by post (varying between 26.0% and 33.7%)., Conclusion: In France, a participation rate of over 50% can be achieved in colorectal cancer screening by means of a faecal occult blood test. To achieve this, primary care physicians have to play an active part in the programme and the test must be mailed to non-consultants.

Considering the present state of knowledge on the question, only the strategy of screening for intestinal tumours at the asymptomatic stage would seem capable of reducing such a problem as colorectal cancer. Detection of occult blood in stool is currently being evaluated through a mass screening test. Methods used to obtain a high participation rate are now well-defined. In France, to achieve this goal, the test must be proposed by GPs and then mailed to those who do not consult GPs. Four case-control studies and one randomized study conducted among volunteers suggest the efficacy of screening with faecal occult blood testing to reduce mortality from colorectal cancer but they do not indicate effectiveness within a population. Four population-based studies have been set up in Europe (Denmark, England, Sweden and France). Results will be available within one to three years. They should lead to a national screening strategy.

Considering the present state of knowledge, only the strategy of screening for intestinal tumours at the asymptomatic stage could reduce such a problem as colorectal cancer. Data from case-control studies provide evidence of the efficacy of screening by rigid proctosigmoidoscopy. But compliance with such a strategy is not known. The effectiveness of screening by sigmoidoscopy has yet to be demonstrated. A European controlled study of flexible sigmoidoscopy in association with the Hemoccult test versus the Hemoccult test alone has been set up. Evaluation by a randomized screening trial with a single flexible sigmoidoscopic examination at age 55 to 60 years has also been suggested. Case-control studies and a randomized study conducted among volunteers demonstrate that it is possible to reduce mortality from colorectal cancer in people who accept screening with faecal occult blood testing, using the Hemocult test. Four population-based studies have been set up in Europe (in England, Denmark, France and Sweden). They are based on a biannual Hemoccult test. Compliance in the test group ranges between 55% and 65% in the first screening campaign and remains high in the following screening campaigns. In France, to achieve this goal, the test must be proposed by GPs and then mailed to those who do not consult GPs. Reliable mortality data will be available within 1 to 3 years. The results of the European trials must be awaited to know if screening biennually is effective in reducing colorectal cancer mortality.