Participation in mass screening for colorectal cancer: results of screening and rescreening from the Burgundy study

A controlled study was made in Burgundy (France) to assess the acceptability and efficiency of colorectal cancer screening using the Hemoccult test. A total of 91,000 people aged 45 to 74 years were included. The first screening campaign was made from January to July 1988 or 1989, and rescreening occurred from January to July 1990. During the first 4 months of the campaign, the General Practitioners (GPs) offered the test to their patients. It was then mailed to all subjects who had not completed it with a recall letter, if necessary, one month later. The overall compliance rate was 54.0% in the first campaign and 55.5% in the second campaign. A total of 63.7% subjects had completed at least one screening test over the two screening campaigns. Compliance was lower among men than women; compliance rate was also lower in the youngest and oldest age group than in the intermediate age groups. During the second screening campaign, the participation rate was 83.6% among participants in the first screening campaign and 20.9% among non-participants. Compliance during the medical offer phase was higher (81.4% during the first campaign, 82.9% during the second campaign) than during the postal offer phase (respectively, 33.8% and 28.5%). It was easier for GPs to propose the test when they had to offer it than when they had to prescribe it. These results suggest that a satisfactory participation rate can be obtained in France if GPs are actively involved in the screening programme. The final objective is to find a 25% difference in 5-year mortality by large bowel cancer between the screened and the test population.

Cerebral haemorrhage in a French prospective population study

The incidence of cerebral haemorrhage was studied from a population-based stroke registry. The incidence was 12.3 per 100,000 per year in women and 13.9 per 100,000 per year in men, with a peak in the eighth decade and a male preponderance. Haemorrhages were deep seated and mostly due to hypertension. Recognised clinical characteristics of haemorrhage are acute onset, convulsion, vomiting, and disturbed consciousness. This study showed that cerebral haemorrhage may present with pure motor deficit or transient deficit preceding the stroke. The mortality was 51% in the first month, and 61% by two years.

Epidemiological evidence for distinguishing subsites of colorectal cancer

The registry of digestive tract tumours established for the department of Cote d'Or (France) was used to study the epidemiological characteristics of large bowel cancer subsites for the period 1976-1983. Age standardised incidence rates for colon cancers were 18.9/100,000 for men and 14.2/100,000 for women. The corresponding rates for rectal cancers were 18.4/100,000 and 10.2/100,000. The sex ratio for right colon cancer (caecum, ascending colon, hepatic flexure, transverse, splenic flexure) was close to 1 and did not change with advancing age, while that for the left colon (sigmoid, descending colon) showed a male excess after 65. For rectal cancer (rectosigmoid junction, rectal ampulla) the male predominance was more marked and occurred earlier, after 55 years of age. There was no significant variation in incidence between rural and urban areas for the different sublocalisations. In males the risk was high in the highest social classes for left colon cancer (p less than 0.01), and among farmers for rectal cancer (p less than 0.01). The risk of left colon cancer in males increased with the comfort of housing (p less than 0.01), but this marker of social class had little influence on incidence for the other localisations in males, or for any localisation in females. No significant variation was found with education. The incidence of colon cancer tended to increase over the 8 years of study. The variations were significant for left colon cancer. For rectal subsites cancer incidence decreased in women (p less than 0.05). The observed differences suggest differences in the aetiological factors within large bowel cancers. Therefore right colon cancer, left colon cancer and rectal cancer should be considered separately in epidemiological analytical investigations.

[Trends in the incidence of colorectal cancer at the Department of Côte-d'Or between 1976 and 1985]

Colorectal cancer is the leading cause of cancer morbidity in France when both sexes are considered together. There are few available data on time trends, although such data would prove both necessary for planning screening programs and usefull to construct hypotheses on etiological factors. Data from the Registre des Tumeurs Digestives de Côte d'Or permitted to establish time trends for the different locations of colorectal cancer during the 1976-1985 period. Changes in incidence rates as based on the world reference population were studied using a log linear model as well as the Armitage test. Overall colon cancer rates have increased in both sexes. The mean annual increase of left colonic cancer was 3.1 p. 100 in men (p less than 0.05) and 4.0 p. 100 in women (NS), whereas rectal cancer decreased by 2.4 p. 100 in men and 3.3 p. 100 in women (NS). In men, left colonic cancer rates increased mainly in rural areas (+ 7.3 p. 100; p less than 0.05) whereas it increased mainly in urban areas in women (+ 6.0 p. 100; NS). In both sexes, the left colonic cancer increase was particularly noticeable in the 45-64 age group, which could indicate that the observed trend is likely to become more important in the next years. As for rectal cancer, the decrease was most important in the 65-74 age groups. That inversed trend for colon and rectum cancer has already been observed in other countries including the USA and Canada. As the trends we observed for right colon, left colon and rectal cancer differ, colorectal cancer etiology should be studied separately.