Rectal cancer (also known as colorectal cancer) is a type of cancer that originates in the lining of the rectum. The rectum is situated at the end of the large intestine and connecting to the anus. Abnormal growth of cells in the inner lining of the rectum can form cluster of cells called polyps, which can either be benign (noncancerous) or malignant (cancerous).
The types of polyps include: Adenomatous polyps, hyperplastic and inflammatory polyps, and Sessile serrated polyps (SSP) and traditional serrated adenomas (TSA). Adenomatous polyps are more likely to develop into cancer than the other types of polyps. Rectal cancer is more common in people over 50 years of age. About 1 out of every 23 men and 1 out of every 25 women will develop rectal cancer.
Lifestyle-related factors, such as diet, weight and exercise, are associated to colorectal cancer risks. Being overweight, having sedentary lifestyle, and eating high amount red meats and processed meats can increase the risk of developing rectal cancer.