Rectal Cancer Overview
The rectum is the lower part of the colon that connects the large bowel to the anus. The rectum's primary function is to store formed stool in preparation for evacuation. Like the colon, the3 layers of the rectal wall are as follows:
In addition to these 3 layers, another important component of the rectumis the surrounding lymph nodes (also called regional lymph nodes). Lymph nodes are part of the immune system and assist in conducting surveillance for harmful materials (including viruses and bacteria) that may be threatening the body. Lymph nodes surround every organ in the body, including the rectum.
Of the 150,000 cases of colorectal cancer diagnosed each year in the United States, more than 40,000 people are diagnosed with rectal cancer. The most common type of rectal cancer is adenocarcinoma, which is a cancer arising from the mucosa. Cancer cells can also spread from the rectum to the lymph nodes on their way to other parts of the body.
Like colon cancer, the prognosis and treatment of rectal cancer depends on how deeply the cancer has invaded the rectal wall and surrounding lymph nodes. However, although the rectum is part of the colon, the location of the rectum in the pelvis poses additional challenges in treatment when compared with colon cancer.
This article only discusses issues related to rectal adenocarcinoma.
Medically Reviewed by a Doctor on 4/8/2014
Timothy Kuo, MD
George Fisher, MD, PhD
Winston W Tan, MD
Mary L Windle, PharmD
Koyamangalath Krishnan, MD, FRCP
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