Rectal cancer occurs when a malignant tumor grows in the lower part of the large intestine, also called the rectum. Often, cancers that affect both the rectum and the main portion of the large intestine (the colon) are grouped together and referred to as colorectal cancer.
Colorectal cancer is the fourth most common type of cancer in all people, after skin, prostate and lung cancer. Most rectal cancers are adenocarcinomas, meaning they begin in the cells that line the rectum.
Causes and Symptoms of Rectal Cancer
Certain risk factors for rectal cancer cannot be controlled. These include things like family history, old age or the presence of rectal polyps, which are growths on the inner walls of the rectum. Crohn’s disease, ulcerative colitis, a poor diet, smoking and a family or personal history of cancer can also increase risk for colorectal cancer.
Rectal cancer often presents few symptoms in its early stages, so the most important tool for fighting it is regular screening by a qualified health care professional. This should begin at about age 50 for most men.
The most common treatment for rectal cancer is surgery to remove a portion of the rectum. Generally, the healthy portions of the rectum and colon will then need to be reconnected. Follow-up treatments are often needed to rid the body of cancer cells in surrounding tissues. This process is accomplished through such treatments as chemotherapy and radiation therapy. Biological therapy may be suggested for some with advanced rectal cancer. It involves the injection of an antibody that binds to cancer cells and halts their growth and spread.
SOURCES: American Cancer Society; U.S. National Cancer Institute