Rectal Cancer

Abstract

In the last year, approximately 140,000 new cases of colorectal cancer were diagnosed, of which, 28 % were in the rectum. The rectum is defined as the area extending from where the taenia coli band together (rectosigmoid junction) to the anorectal junction, about 3.5 cm from the anal verge. This area measures approximately 12–16 cm and is divided into the lower rectum (3.5–8 cm), the middle rectum (8–12 cm), and the upper rectum (12–16 cm). From an oncologic standpoint, tumors in the mid to distal rectum, which are below the peritoneal reflection, hence extraperitoneal, behave differently than those of the upper rectum, which act similar to colon cancer. There are many different histological types of rectal cancer including squamous cell, neuroendocrine, sarcoma, lymphoma, and adenocarcinoma, the most common subtype and the focus of this chapter.