Definition

     Colon cancer is cancer that starts in the large intestine (colon) or the rectum (end of the colon). Such cancer is sometimes referred to as "colorectal cancer."

     Other types of colon cancer such as lymphoma, carcinoid tumors, melanoma, and sarcomas are rare. In this article, use of the term "colon cancer" refers to colon carcinoma and not these rare types of colon cancer.

Risk Factors

• Adenomatous polyps

• Age over 50

• Family history of Colorectal Cancer

• Ulcerative colitis

• History of gynecologic cancer

• Barrett's esophagus syndrome

• Genetic nonpolyp syndromes

• Familial polyposis syndromes (i.e., genetic diseases with multiple Colon Polyps)

Symptoms

• May be none

• Fatigue

• Weakness

• Change in bowel habits

• Diarrhea -- new

• Constipation -- new

• Abdominal pain

• Pain in rectum after a bowel movement

• Blood in bowel movements

Screening and Diagnostics

1. Colonoscopy

2. CT scan of abdomen to check for spread of cancer

3. Rectal Ultrasound for rectal cancer

Treatment

• Surgical removal of the cancer

• Surgical removal of metastases (tumor spread) to liver and lung may be considered.

• Chemotherapy and/or radiation treatment for more advanced Colorectal Cancer.

Prognosis

     How well a patient does depends on many things, including the stage of the cancer. In general, when treated at an early stage, more than 90% of patients survive at least 5 years after their diagnosis. (This is called the 5-year survival rate.) However, only about 39% of colorectal cancer is found at an early stage. The 5-year survival rate drops considerably once the cancer has spread.

     If the patient's colon cancer does not come back (recur) within 5 years, it is considered cured. Stage I, II, and III cancers are considered potentially curable. In most cases, stage IV cancer is not curable.

Complications  

• Cancer spreading to other organs or tissues (metastasis)

• Recurrence of carcinoma within the colon

• Development of a second primary colorectal cancer

Prevention 

     The death rate for colon cancer has dropped in the last 15 years. This may be due to increased awareness and screening by colonoscopy. Colon cancer can almost always be caught in its earliest and most curable stages by colonoscopy. Almost all men and women age 50 and older should have a colonoscopy. Colonoscopy is almost always painless and most patients are asleep for the entire procedure.

     Dietary and lifestyle modifications are important. Some evidence suggests that low-fat and high-fiber diets may reduce your risk of colon cancer.

     Some evidence suggests that non-steroidal anti-inflammatory drugs (NSAIDs) may help prevent colon cancer.