Doctors may be overdoing it a bit on colonoscopies, even though they can save lives, researchers reported on Monday

Patients who had a low-risk polyp removed in a first colonoscopy do not need to have repeat colonoscopies as often as many doctors are prescribing them, the researchers report in this week’s issue of the Annals of Internal Medicine.

“We believe colonoscopy can be a life-saving procedure, but it shouldn’t be done more often than necessary,” said Dr. Pauline Mysliwiec, an assistant professor of gastroenterology at the University of California Davis.

“When it’s used inappropriately, it strains health care resources and puts patients at unnecessary risk.”

Colonoscopies involve threading a flexible fiber-optic tube through the rectum into the colon and are the most accurate way to screen for colon cancer. People over 50 are advised to undergo the procedure every 10 years.

The American Cancer Society estimates that 147,000 Americans will be diagnosed with colorectal cancer this year and 57,000 will die from the disease.

Mysliwiec and colleagues at the National Cancer Institute surveyed gastroenterologists and general surgeons about their colonoscopy recommendations in 1999 and 2000.

Medical guidelines on how often patients should have a followup colonoscopy do not call for surveillance after removal of a hyperplastic polyp, a benign growth not believed to become cancerous.

People with such growths should only have the recommended colonoscopy every 10 years after age 50.

Yet they found that 24 percent of the gastroenterologists and 54 percent of the general surgeons surveyed recommended surveillance colonoscopy every three to five years for a small, hyperplastic polyp.

“Overuse of colonoscopy taxes the health care system and may compromise the quality of care,” the researchers wrote.

“Long waiting times of several months are already occurring in some parts of the country and could mean reduced access for symptomatic patients and those with limited means.”

A colonoscopy costs between $1,500 to $1,700 in the United States.

In a second report, the American Society of Clinical Oncology issued new recommendations saying patients who have been successfully operated on for stage II colon cancer do not need any chemotherapy.

Writing in the Journal of Clinical Oncology, they said patients who get chemotherapy after surgery have only about a 4 percent to 5 percent greater chance of survival five years after surgery, compared with patients who had surgery alone.

“It is critical for each patient to weigh the risk of therapy and any potential benefit,” said Dr. Al Benson, director of the Robert H. Lurie Comprehensive Cancer Center’s Clinical Investigations Program at Northwestern University.

SOURCE: Annals of Internal Medicine, August 17, 2004.