[Estimate of regional prevalence of colorectal cancer in France].

Background: Colorectal cancer prevalence is an important determinant of the health demand that completes information provided by cancer incidence. Current estimations established from data for the years 1985 and 1995 can be used to establish a precise description of changing healthcare needs for colorectal cancer.
Method: Prevalence estimates method were based on incidence data computed on the regional scale by the FRANCIM network and mortality data provided by INSERM. We used the relationship that exists between the net risk of cancer, the net risk of dying of the given cancer and the age-specific prevalence of cancer.
Results: In 1995, the prevalence of patients who had a diagnosis of colorectal cancer amounted to 200 000 persons. The estimated number of prevalent cases was never lower than 3500 in any region and in 7 regions this number was higher than 10 000. From 1985 to 1995, there has been an increase of 35% in the prevalence rates.
Conclusion: The evaluation of the number of persons who have had a diagnosis of colorectal cancer provides knowledge for health care planning. Such information on the regional scale is very useful for the health organisation (SROS). This geographical level induces difficulties not encountered at the national level.