Lifewatch: Colon cancer study

Reported by Claire Hosmann - email
Posted by Debra Worley - email

(WECT) - Colon Cancer is the third most common form of cancer with 150,000 diagnoses each year.

Now, doctors are investigating drugs that may stop the disease before it begins.

38-year-old Ivelisse Page is a mother of four, and colon cancer was not part of her plan.

Half of those over 50 years old will develop a colon polyp at some point in their lives.  Over time, the clumps of cells may turn into cancer.

"If we could stop them presumably, the mortality due to colon cancer will also go down by more than 50%," said Dr. Eugene Gerner.

The anti-inflammatory drug Sulindac and the cancer-fighting compound DFMO were tested on people with a history of polyps.

Results showed it stopped them from returning up to 95% of the time.

The University of Arizona and University of California are collaborating on this colon cancer research project.  They say more clinical trials are planned for 2009.

For more information, please contact:
Sara Hammond, Director of Public Affairs
Arizona Cancer Center
(520) 626-2277

BACKGROUND: Approximately 150,000 people are diagnosed with colon cancer a year, according to the American Cancer Society. It's the third most common form of cancer. Colon cancer affects the colon (large intestine), or the lower part of the digestive system. The disease usually starts as small, benign clumps of cells known as polyps. Several types of polyps exist, but three occur with the most frequency. Adenomas are polyps that have the potential to become cancerous. They tend to be removed during screening tests. Hyperplastic polyps hardly ever pose a risk of developing into colon cancer. The third most common type of polyp, inflammatory polyps, may become cancerous. Such polyps are associated with Crohn's disease and ulcerative colitis. Colon polyps develop when chromosomal damage occurs in the cell's inner lining of the colon. Usually healthy and undamaged chromosomes control cell growth in an orderly manner, but when chromosomes are damaged, cell growth results in masses of extra tissues (polyps). Benign polyps form from this process, but over the years, the non-cancerous polyps can acquire further chromosome damage and become cancerous.

Doctors believe most colon cancers develop in colon polyps. Therefore, removing and preventing the development of colon polyps may also prevent colorectal cancer. Polyps may be small and produce very few symptoms. Having colonoscopies done regularly can help identify cancerous polyps. Signs of colon cancer include bowel habit changes, blood in stool, abdominal pain, eight loss, fatigue and persistent cramping. Risk factors include age, polyps of the colon, diet, heredity, smoking, alcohol and environmental factors. Those who are over age 50, have a diet high in red meats, smoke, drink and a family history of cancer increases the possibility of getting colon cancer.

PREVENTING POLYPS: A new combination of drugs has been shown to reduce the risk of colon cancer by preventing the recurrence of polyps. The treatment combines a low dose targeted cancer-fighter known as diflouromethylorinithine (DFMO) with a non-steroidal, anti-inflammatory drug known as sunlindac (NSAID). In a study of the therapy, 375 patients with a history of at least one colorectal polyp were randomly assigned to either the drug treatment or placebo treatment.

For three years, doctors monitored these patients to measure polyp reoccurrence. Results of the study were promising. Doctors found it reduced the risk of recurrent colorectal polyps by up to 95 percent. "It's the first example of a combination chemo prevention for cancer that really works," Eugene Gerner, Ph.D., director of the Gastrointestinal Cancer Center at the Arizona Cancer Center in Tucson, Ariz., was quoted as saying. "This trial is the biggest possible prevention ever detected for any cancer trial."