Colorectal Cancer

What It Is

Colorectal cancer is a cancer that has developed in the large intestine, either in the colon or the rectum. The colon makes up the first 6 feet of the large intestine, while the rectum makes up the last 8 to 10 inches. These cancers may be referred to as colon cancer or rectal cancer, depending on their specific location, but because there are many similarities between the two cancers, they are often referred to as simply colorectal cancer.

 

Colorectal Cancer Stages

When someone is diagnosed with colorectal cancer, his or her doctor needs to determine the extent of the cancer and whether cancer cells have spread to other parts of the body. This determines the stage of the cancer and helps determine treatment.

Colorectal cancer typically starts in the innermost lining of the digestive tract. Staging of colorectal cancer is based on how far the tumor penetrates through the wall of the colon or rectum, whether the cancer has spread to nearby lymph nodes, and whether the cancer has metastasized to other parts of the body. The following stages are used to describe colorectal cancer:

• Stage 0: The cancer is a very early cancer and is confined to the innermost lining of the colon or rectum.
• Stage I: The cancer spreads within the colon or rectal wall but has not gone through it.
• Stage II: The cancer has spread outside the colon or rectum to nearby tissue but has not spread to the lymph nodes.
• Stage III: The cancer has spread to the nearby lymph nodes but not to other parts of the body.
• Stage IV: The cancer has spread to other parts of the body, most commonly the liver or lungs.

Recurrent: Colorectal cancer is said to be recurrent if it has come back after it has been treated. It can reappear in the colon or rectum, or in other parts of the body, such as the lower abdomen, liver, lungs.

 

Who Is More At Risk

According to the American Cancer Society, colorectal cancer is the third most common cancer diagnosed in men and women in the United States, excluding skin cancers. It estimates that about 106,370 new cases of colon cancer and 40,570 new cases of rectal cancer will be diagnosed in 2004.

Colon cancer is most often found in people who are over the age of 50. However, it can occur at younger ages, and in rare cases, has been reported in teenagers.

The causes of colorectal cancer are unknown. However, several factors have been shown to be associated with an increased risk for this type of cancer. These include:

Older age: Colorectal cancer is more common in people over the age of 50.

Dietary factors: An increased risk for colorectal cancer has been suggested in people who consume a diet that is high in fat and calories and low in fiber.

History of polyps: Polyps are non-cancerous (benign) growths found on the inner walls of the digestive and respiratory tracts. Polyps in the colon and rectum are common in people over the age of 50 and some are associated with an increased risk of colon cancer.

Certain hereditary conditions: Certain inherited conditions increase a person's risk of developing colorectal cancer. One of these conditions is familial adenomatous polyposis, a rare disorder that causes hundreds of polyps to form in the colon and rectum. These polyps often develop into cancer.

Personal history of cancer: A person who has had colorectal cancer in the past is at increased risk of developing it again. A woman who has had cancer of the ovaries, uterus, or breast also has an increased chance of developing colorectal cancer.

Family history of cancer: A person who has a first-degree relative (ie, parent, sibling, or child) with colorectal cancer is somewhat more likely to develop colorectal cancer.

Ulcerative colitis: Having a condition known as ulcerative colitis increases a person's risk of developing colorectal cancer. Ulcerative colitis is a condition whereby the lining of the colon is chronically inflamed.

It is important to remember that having one or more of these risk factors does not mean a person will develop colorectal cancer. It just increases a person's risk.

 

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