Study title

Background Most cases of colorectal cancer develop from polyps. A study conducted in Telemark from 1983-1996 (Telemark Polyp Study no. I, TPS-I) showed that systematic endoscopic examinations (sigmoidoscopy) with removal of polyps (wart-like growths on the intestinal mucosa) could reduce the incidence of colorectal cancer. Other studies have shown that mass screening for blood in the stool can reduce mortality from colorectal cancer through early detection of cancer, i.e., before the patient has symptoms. The advantage of endoscopy over stool blood tests is that endoscopy can more easily detect (and simultaneously remove) polyps before they can potentially develop into cancer. The greatest benefit is expected from the detection of high-risk adenomas. Adenomas are a type of polyp that can develop into cancer, but the risk is likely very small. High-risk adenomas, however (five percent of all adenomas), have a high risk of developing into cancer. Objective The main objective of the project is to investigate whether early detection and removal of polyps can reduce the incidence and mortality of colorectal cancer. The results from TPS-I are very promising, but we know little about how such mass screening works in a larger population group. Organization NORCCAP is a prospective randomized study in which 21,000 men and women aged 50-64, residing in Oslo or Telemark, were randomly selected from the population registry and offered a screening examination with sigmoidoscopy or a combination of sigmoidoscopy and fecal occult blood test. The screening phase was conducted over 3 years (1999-2001). There are several sub-studies associated with the project aimed at simplifying and optimizing any potential future screening programs. The project is funded by the Cancer Society and the Ministry of Health and Care Services via the Cancer Registry.