The exact cause of colorectal carcinoma in situ is not fully understood, but several risk factors have been identified. These include genetic predisposition, such as hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP), lifestyle factors such as a diet high in red and processed meats, smoking, excessive alcohol consumption, and a lack of physical activity. Chronic inflammatory conditions of the colon, like ulcerative colitis and Crohn's disease, may also contribute to the development of colorectal carcinoma in situ.
