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6 Common Cancers - Colorectal Cancer

White House Press Secretary Tony Snow

White House Press Secretary Tony Snow has returned to work following surgery for a recurrence of colon cancer.
Photo: AP Photo/Ron Edmonds

Colorectal Cancer

Cancer of the colon (large intestine) or rectum (end of the colon) is called colorectal cancer. In the United States, it is the third most common cancer in men and women. Caught early, it is often curable. It is more common in people over 50, and the risk increases with age. Deaths from colon cancer have fallen nearly 9 percent in the past decade. Better and earlier screening gets much of the credit, along with better treatments, but the cause of the disease is still unknown.

Screening and Diagnosis

You are more likely to get colorectal cancer if you have polyps, growths inside the colon and rectum that may become cancerous. A family history of colon or rectal cancer puts you at higher risk, as does ulcerative colitis or Crohn's disease (also known as inflammatory bowel disease). Symptoms can include blood in the stool, narrow stools, a change in bowel habits, and general stomach discomfort. However, you may not have symptoms at first, so screening is important. Everyone who is 50 or older should be screened for colorectal cancer. The most thorough examination of the colon is done with a colonoscope, which is inserted into the rectum. A colonoscope is a thin, tube-like instrument, with a light and a lens for viewing. It may also have a tool to remove tissue (polyps) to be checked under a microscope for signs of disease.


Standard treatments include surgery, chemotherapy, radiation therapy, or a combination of these methods. Treatment depends partly on the stage of the cancer. At the earliest stage (stage 0), doctors may treat colon cancer with localized surgery, possibly by removing the cancer cells during a colonoscopy. For stages I, II, and III cancer, more extensive surgery is needed. With advanced colorectal cancer, your doctor will most likely prescribe chemotherapy. While radiation therapy is occasionally used in patients with colon cancer, it is usually used in combination with chemotherapy for patients with advanced rectal cancer.

Research: What's New

  • Combination chemotherapy: Until recently, standard chemotherapy for colorectal cancer usually consisted of treatment with just two drugs, 5-fluorouracil (5-FU) and leucovorin. A third drug, irinotecan, was approved by the FDA in 1996 for use in combination with 5-FU and leucovorin in treating metastatic colorectal cancer (cancer that has spread to other parts of the body). Since then, the drug oxaliplatin has also been approved for use in combination with 5-FU and leucovorin to treat metastatic colorectal cancer and post-surgical treatment of this cancer. Unfortunately, traditional chemotherapy agents often affect healthy cells, in addition to cancer cells, leading to a variety of side effects.
  • Monoclonal antibodies: Targeted monoclonal antibody therapies — bevacizumab (Avastin) and cetuximab (Erbitux) — have been available since 2004. One advantage of these targeted therapies is that they usually have fewer side effects than chemo drugs. Bevacizumab targets a protein that tumors use to help them grow new blood vessels. The blood vessels let the tumors get the oxygen and nutrients they need to keep growing. Cetuximab targets a protein found on the surface of tumor cells that helps promote cell growth and multiplication. Both antibodies are approved only for people with cancer that has metastasized, and they haven't yet been shown to work in earlier stages of the disease. In addition, bevacizumab may increase the risk of heart attacks and strokes, making it unsafe for certain people.

Read More "6 Common Cancers" Articles
Lung Cancer / Breast Cancer / Prostate Cancer / Colorectal Cancer / Skin Cancer / Gynecologic Cancers

Spring 2007 Issue: Volume 2 Number 2 Page 11