Colorectal Cancer/Colon and Rectal Cancer

The colon and rectum are parts of the body's digestive system. The digestive system consists of a group of organs where the food is processed to create energy and the waste material is stored until it passes out of the body as stool. Together, the colon and rectum form a long, muscular tube called the large intestine. The colon is the first 6 feet of the large intestine, and the rectum is the last 8 to 10 inches.

Cancer occurs when cells in a part of the body begin to grow out of control. This uncontrollable growth of abnormal cells crowds out the normal cells and replaces them. The walls of the colon and rectum have several layers of tissues. Colorectal cancer begins in the innermost layer and slowly spreads to the other layers as the disease progresses.

Cancer cells can sometimes break away from a tumor and spread to other parts of the body through the blood or lymph system. Cancer that has spread in this way is called metastatic cancer. When cancer comes back in a person who appeared to be free of the disease after treatment, it is called a recurrence.

Most colon cancers are adenocarcinomas, which are cancers that begin in cells lining the inner layer of the colon. They may not manifest until they either bleed or grow in size to the extent that they block the lumen of the intestine. Treatment of these cancers may involve surgery, chemotherapy, biological therapy or radiation therapy. Some people have a combination of treatments.

There seems to be an increasing incidence of these cancers in the older age group and in some patients who have a strong family history of the disease. There are now simple tests that can help in early diagnosis and cure of these cancers.