Colon Cancer

The colon and rectum are part of the digestive tract. Together, they comprise the large intestine, or large bowel, which is located in the abdomen between the small intestine and the anus. Cancer that originates in the colon or rectum may be called colon cancer, rectal cancer, or colorectal cancer. Colon cancer is the term most commonly used to refer to this type of cancer.

Most (over 95%) colon cancers are adenocarcinomas that develop when a change (i.e., mutation) occurs in cells that line the wall of the colon or rectum. The disease often begins as an intestinal polyp, also called an adenoma, which is an abnormal growth of tissue. Polyps gradually can become precancerous and then cancerous.

Risk Factors

Age - Age is the primary risk factor. Incidence of the disease increases significantly after the age of 50.

Genetic - Some people have a genetic predisposition to carcinogenic (i.e., cancer causing) effects of the diet on the digestive tract, which increases the risk for colorectal cancer. When this predisposition is combined with a high dietary intake of fat and red meat and a low dietary intake of fiber (e.g., bran), vitamins (e.g., folate), and minerals (e.g., calcium), the risk is even higher. Ashkenazi Jews have a higher incidence of a specific genetic mutation (called I1307K) that increases the risk for colorectal cancer.

Lifestyle factors - Lifestyle factors that increase the risk include the following:

• Daily alcohol use (may double the risk)
• Eating a high-fat, low-fiber diet
• Obesity
• Sedentary lifestyle
• Smoking

Recent studies have shown that a high intake of dietary fiber may not significantly reduce the risk for colon cancer.

Hereditary - A family history of intestinal polyps or colorectal cancer (especially before the age of 60) results in an increased risk for the disease. Other diseases and medical conditions that increase the risk include the following:

• Diabetes
• Genetic disorders such as familial polyposis syndromes and hereditary non-polyposis colon cancer syndrome (HNPCC)
• Inflammatory bowel disease (e.g., ulcerative colitis, Crohn's colitis, granulomatous colitis)
• Personal history of intestinal polyps or colorectal cancer

Prostate Cancer Treatments

Chemotherapy - Chemotherapy is a systemic treatment (travels throughout the body via the bloodstream) that often uses a combination of drugs to slow tumor growth and destroy cancer cells. Drugs may be administered orally or intravenously (through a needle in a vein). In some cases, chemotherapy drugs can cause an allergic or hypersensitivity reaction. These reactions, which may be severe and are triggered by an immune system response, can occur immediately or within hours or days of treatment.

Chemotherapy is often used as a first-line treatment for metastatic colorectal cancer to destroy cancer cells that have metastasized (spread). It also may be used prior to surgery (called neoadjuvant therapy) to shrink the tumor, may be administered following surgery (called adjuvant therapy), and may be combined with biological therapy (also called immunotherapy) and radiation therapy.

Immunotherapy - Immunotherapy, or b