There are four stages of colorectal cancer, and stage 3 is among the most serious. When a person has stage 3 colorectal cancer, this means he has cancer of the part of the intestine that is referred to as the colon or the rectum, and the diseased cells have spread beyond the part of the intestine in which the cancer developed. Stage 3 colorectal cancer means the cancerous cells have spread beyond the outer muscular layer of the colon and perhaps to nearby lymph nodes, but have yet to progress to other organs in the body.
The stages of colorectal cancer start with stage 0 and extend through stage 4. The stages indicate how far the cancer has progressed or spread, with stage 0 being a very early stage of the cancer and stage 4 being the most serious. Doctors also use staging to determine which courses of treatment will prove best for their patients. For example, a person with stage 4 colorectal cancer may benefit from such treatments as surgery, radiation therapy, and chemotherapy while a person with stage 0 colorectal cancer may only need surgery.
When a person has stage 3 colorectal cancer, the cancer has progressed outside the inner wall of the colon or rectum to which it was limited in early stages of the disease. Once the cancer has reached this stage, it has moved through a muscle layer of the intestine called the muscularis propria and has begun to affect the outer layers of the patient's colon or rectum. While cancer in this stage has moved to the outermost layer, it has not gone beyond it. Other organs in the body are not yet affected at this stage, though the cancer may have spread to lymph nodes nearby.
The fact that stage 3 colorectal cancer has not yet reached other body organs is an important consideration. When cancer is confined to one part of the body, it is easier to treat, and the patient's diagnosis is better than in stage 4 when the cancer invades other body tissues and organs. Still, stage 3 colorectal cancer is very serious and associated with a poorer prognosis than the earlier stages of this type of cancer.
Treatment for stage 3 colorectal cancer may include surgery as well as chemotherapy and radiation treatments. Surgery is typically used to remove the diseased parts of the colon or rectum. Chemotherapy and radiation therapy are used to destroy the cancer cells.
