Too Many Repeat Colonoscopies Performed
Screening Those Who Don't It Need May Put Others at Risk, Experts Say
Aug. 16, 2004 -- Doctors are performing too many follow-up colonoscopies on patients who have had benign colon polyps removed. This may make the procedure less available for others and may delay the diagnosis of colorectal cancer, a nationwide survey suggests.
After a precancerous colon polyp is removed, guidelines call for a follow-up or surveillance colonoscopy to check for precancerous polyps that may develop later. Surveillance colonoscopy is done every three to five years.
In the National Cancer Institute-funded survey, led by researchers at the University of California at Davis, roughly a quarter of the gastroenterologists -- doctors that commonly perform colonoscopies -- and half of the general surgeons reported deviating from these guidelines.
They reported performing follow-up colonoscopies on patients with small, benign growths called hyperplastic polyps. No repeat colonoscopy is recommended for these patients. In addition, they were also likely to perform repeat procedures on patients with small, single lesions -- called adenomas -- more often than recommended.
"Colonoscopy is a potentially limited resource from both a manpower and financial standpoint," study researcher Pauline Mysliwiec, MD, tells WebMD. "If physicians are over-performing surveillance, it can certainly impact the availability of screening for those who either haven't been screened or are symptomatic and need to be screened in a timely fashion."
An estimated 12 million to 18 million Americans have colon polyps, but some of these growths are more dangerous than others. A colonoscopy involves a lighted tube that is able to view the entire colon to check for any abnormal growths.
Long Waits Reported
An estimated 147,000 Americans are diagnosed with colorectal cancer each year, and nearly 57,000 die from the disease. Just about all of these deaths could be avoided, experts say, if existing screening guidelines were universally followed.
Colonoscopy is a highly effective tool for both the diagnosis and prevention of colorectal cancer. Not only does it help identify early colorectal cancer, but the doctor can also remove precancerous growths before they become larger or turn into cancer.
Mysliwiec and colleagues surveyed a nationally representative sample of 349 gastroenterologists and 316 general surgeons for the study, published in the Aug. 17 issue of the Annals of Internal Medicine.
They report that 24% of the gastroenterologists and 54% of the general surgeons said they recommended surveillance colonoscopy for hyperplastic polyps, even though they guidelines say every 10 years is fine.
Half of those questioned also recommended follow-up colonoscopy every three years or less for patients with a single, small, low-risk adenoma instead of every five years, as the guidelines call for.
"Overuse of colonoscopy taxes the health care system and may compromise the quality of care," the researchers write. "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."
Mysliwiec tells WebMD she hopes the findings will lead to better scrutiny of colorectal screening practices nationwide.