what is the most common type of rectal cancer ?
From Medscape: “Background Almost all rectal cancers are primary adenocarcinomas. Adenocarcinoma of the rectum is a major cause of mortality and morbidity in North America and Western Europe. Rectal cancers are, after colon cancers, the second most common gastrointestinal (GI) carcinoma, and have the best prognosis. The 5-year survival rate is approximately 50%. Screening for and removing adenomatous polyps may improve survival rates. Adenocarcinoma of the rectum arises as an intramucosal epithelial lesion, usually in an adenomatous polyp or gland. As cancers grow, they invade the muscularis mucosa, lymphatic structures, and vascular structures and involve regional lymph nodes, adjacent structures, and distant sites, especially the liver. Many factors increase the risk for rectal cancer, including the following: High-fat, low-fiber diet Age greater than 50 years Personal history of colorectal adenoma or carcinoma (3-fold greater risk) First-degree relative with colorectal cancer (3-fol
