-Diagram of the large bowel and colon.

Facts About Colorectal Cancer

• The American Cancer Society estimates 106,100 new cases of colon cancer in the United States in 2009.
• Colorectal cancer is the third most common cancer in both men and women.

General Risk Factors for Colorectal Cancer

The greatest risk factor is age. More than 90 percent of all colorectal tumors are found in patients over age 50. However, the disease can happen at any age, so it is important to know your family history and the following risk factors:

• Personal history of colorectal cancer, polyps in the colon, ulcerative colitis or Crohn's disease.
• Obesity, physical inactivity, smoking, drinking alcohol in excess and eating too much red meat and not enough fruits and vegetables may also put you at risk of developing the disease.

Signs of Colorectal Cancer

Often there are no obvious signs of colorectal cancer, but some symptoms can include:

• Change in bowel frequency, such as alternating episodes of diarrhea and constipation.
• Bloody bowel movements or rectal bleeding.
• General abdominal discomfort.
• Bloating.
• Unexplained weight loss.
• Chronic fatigue.
• Unexplained anemia.

Diagnosing Colorectal Cancer

Special tests to evaluate the colon and rectum are used to detect and diagnose colorectal cancer. Your physician may perform the following to help diagnose colorectal cancer:

• A physical exam to assess your overall health, including a digital rectal exam to evaluate the rectum for abnormal masses.
• A test for blood in your stool.
  
• A sigmoidoscopy to look inside the rectum and sigmoid colon for polyps or other abnormal areas that may be cancerous. Your doctor uses a thin, lighted tube.
  
• A double-contrast barium enema, in which the colon and rectum are examined with X-rays showing the inside of the bowel.
  
• A colonoscopy using a long, flexible lighted tube to look inside the rectum and the entire colon. Your doctor is looking for polyps or other abnormal areas that may be cancerous.
  
• To determine for sure whether you have cancer, some tissue will be removed during sigmoidoscopy or colonoscopy and examined under a microscope. This test is called a biopsy.
  
• Patients with colorectal cancer often require additional scans to see whether the cancer has spread.
  

Treating Colorectal Cancer

For rectal cancer, radiation therapy is usually given with chemotherapy. It can be given before or after surgery. Depending on your tumor, radiation therapy before surgery may allow the surgeon to spare your anus. This would avoid the need for a permanent colostomy and may reduce the chance of the cancer coming back.

Additional Information