EFFECTIVENESS OF EARLY INFORMATION AND ENDORSMENT BY GP TO INCREASE COLONOSCOPY FOLLOW-UP AND REDUCE DELAYS IN PEOPLE WITH A POSITIVE COLORECTAL CANCER SCREENING TEST. (SUIVICOLO)

To be effective, organized colorectal cancer screening requires good adherence to diagnostic colonoscopy in the event of a positive test. In France, the rate of diagnostic colonoscopy following a positive colorectal cancer screening test is less than 85%, and the median delay is close to 90 days. After receiving their positive result from the laboratory, individuals with no known follow-up are contacted only six months later by the Regional Cancer Screening Coordination Centers (CRCDC) responsible for following up with individuals who have tested positive. To optimize follow-up with colonoscopy, earlier contact and information about colonoscopy appear to be necessary. The contribution of the general practitioner identified on the test could be an additional lever. The SUIVICOLO study aims to evaluate the effectiveness on the rate of colonoscopies performed at 6 months of two strategies for optimizing the follow-up of positive results in comparison with control group C (current procedures of the CRCDC Centre Val de Loire without early letter). The two strategies evaluated will be: * Group B1: Sending an early letter signed by the CRCDC accompanied by information leaflet about colonoscopy * Group B2: Sending an early letter co-signed by the CRCDC and the general practitioner (identified or provided by the patient on the test identification form) accompanied by information leaflet about colonoscopy. These strategies will be compared to the current follow-up strategy in a three arm randomized controlled arm.