Colonoscopy proves cost-effective for younger patients but questionable in older ones

Conducting colonoscopies for people in their midfifties saves money, but screening in those older than 75 may not be beneficial, according to a government policy group.

Research presented in September at the 2008 American College of Gastroenterology’s meeting showed that screening for colon cancer at age 55 would save at least two dollars for every dollar spent.

The U.S. Preventive Service Task Force (USPSTF), a unit of the Department of Health and Human Services’ Agency for Healthcare Research and Quality (AHRQ), reiterated its long-standing support for colon cancer screening beginning at age 50 but recommended screening cease when individuals reach 75.

At the ACG meeting in Orlando, Dr. Jianjun Li and colleagues from Maimonides Medical Center in Brooklyn reported results of a study involving free screening colonoscopies for 248 consecutive patients. Their average age was 55, and nearly 45% had polyps. Follow-up testing demonstrated that five individuals had early-stage colon cancer, and 22 had polyps larger than 1 cm. The screening program cost $390,000.

If these patients had not been screened, their cancers and polyps would have progressed undetected, according to Dr. Judy Yee, vice chair of radiology at the University of California, San Francisco.

It is more cost-effective to catch cancer early. If colon cancer treatment had been delayed until the Medicare eligibility age of 65, the cost would have been nearly $1.3 million, Li said.  

It makes sense to begin screening earlier because the older people get, the greater their risk of developing polyps, Yee said. About one in four people older than age 50 have a polyp.

“Almost all polyps will be insignificant, but we would miss all of them if we didn’t screen,” she said.

In March, the American Cancer Society, the U.S. Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology jointly recommended screening for colorectal cancer beginning at 50 years of age. For many uninsured patients in the U.S., however, lack of coverage poses a barrier to screening. Medicare coverage doesn’t begin until age 65, creating a coverage gap.

Only half of all adults in the U.S. age 50 and older have undergone a colonoscopy to screen for colorectal cancer, which is the second leading cause of cancer death in the U.S., according to the AHRQ. About 77% of uninsured adults between the ages of 50 and 64 have never been tested.

Though the Maimonides Medical Center study highlights the cost-effectiveness and life-saving potential of screening 10 years before Medicare coverage, some authorities have concluded screening is less beneficial later in life.  

The USPSTF recommends fecal occult blood testing, sigmoidoscopy. or colonoscopy to screen for colorectal cancer among adults beginning at age 50 but concludes that screening should cease after an individual reaches age 75. Its recommendations were published Oct. 7 in an online version of the Annals of Internal Medicine and will appear in print Nov. 4.

The task force selected 75 as an age to cease screening because it considered the net benefits of screening after that age to be small. After age 85, the possible harms from screening outweigh the benefits, the USPSTF said.

The age ceiling does not sit well with some sources. Dr. Perry Pickhardt, an associate professor of radiology at the University of Wisconsin School of Medical School, noted the standard age to stop routine screening has generally been 79. This can be shifted up or down on a case-by-case basis depending upon the health of the patient.

“Screening may be worthwhile in a healthy 80-plus-year-old but not for-a 70-year-old with multiple comorbidities,” he said.

Yee also disagreed with an age limit.

“We are an aging population, and as people live longer, we don’t know how long they’ll be alive. How can you come up with a hard and fast age?” she said.

For more information from the Diagnostic Imaging archives:

PET meets universal cancer screening

Radiology societies seek Medicare coverage for CT colonography

CMS commences national coverage analysis for CT colonography