Familiäres Kolonkarzinomrisiko – überschätzt oder real?

Background: Approximately15 % of colorectal cancer (CRC) patients have a positive family history, i.e. at least one first degree relative of these patients was also diagnosed with CRC. Available review articles regarding CRC risk among first degree relatives of CRC patients do not distinguish between familial and hereditary CRC risk. Objectives: This article provides a literature review of various studies that describe familial risk of CRC (as distinguished from the CRC risk in persons with hereditary CRC syndrome) and discusses aspects regarding CRC screening among patients with a familial CRC risk. Material and methods: This review article is based on a selective literature search, including current guidelines and recommendations. Results and discussion: Case control studies that focused on persons with a familial risk of CRC suggest an approximately twofold increased risk of developing CRC. It has also been described that advanced adenomas are more prevalent among these persons as compared to persons with no family history of CRC, which is also indicative of an increased CRC risk. This increased risk is considered in current S3 guidelines, which recommend persons with a familial risk of CRC to undergo complete colonoscopy (10 years before age at diagnosis of the first degree relative and no later than 40–45 years of age). To optimize this recommendation regarding the starting age for screening, studies that provide age-specific relative risk estimates for persons with a familial versus a hereditary CRC risk separately would be helpful. The distinction between both subgroups is also relevant for other research questions that are to be addressed regarding a familial CRC risk.