When elderly Medicare (search) patients are diagnosed with colon cancer (search), it’s often the first time they’ve ever been tested for the disease. That defies screening guidelines, say the Cleveland researchers who report the finding.

Gregory Cooper, MD, is on staff at University Hospitals of Cleveland. Jonathan Payes, MS, works at Case Western Reserve University. Their study is scheduled to appear in the Feb. 15 issue of the journal Cancer.

Colorectal cancer (search) is the second leading cause of cancer death in the U.S. Most colorectal cancers and deaths from the disease are preventable through screening.

Across the board, medical professional organizations recommend colon cancer screening every 10 years for adults with average risk. Methods include colonoscopy (search), sigmoidoscopy (search), fecal occult blood test (search), barium enema (search), and virtual colonoscopy. Colonoscopy is currently considered the best but no test is perfect.

Typically, people are advised to get their first test at age 50. But that doesn’t always happen, as Cooper and Payes learned.

They studied 5,800 people age 70 or older. All had been diagnosed with cancer of the colon or rectum in 1999 and were eligible for Medicare for at least five years before their diagnosis. Data came from a Medicare database.

More than half of the group -- 56 percent -- hadn’t had one of the screening procedures until within six months of their diagnosis. That means those patients missed at least two decades of colon cancer screening, by current recommendations.

In many of the patients, their colon cancers were probably caught the first time they were screened, say the researchers.

The remaining participants had a better track record. Forty-four percent had been tested, at least once, more than six months before their diagnosis. Their cancers were caught at earlier stages, which are often easier to treat.

Fecal occult blood test was used by most participants (36 percent) who had been screened for colon cancer more than six months before their diagnosis. But very few participants (6 percent) had ever had colonoscopy before that.

The researchers didn’t get a chance to talk to participants about why they avoided screening. Many people are squeamish about colonoscopy, which involves inserting a thin, flexible, lighted scope into the colon to look for signs of cancer.

In this particular group, money might also have been a factor. Before 1998, routine colorectal cancer screening wasn’t reimbursed for Medicare beneficiaries, write the researchers. The results might not apply to younger patients and those not using Medicare, they add.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Cooper, G. Cancer, Feb. 15, 2005; vol 103. WebMD Public Information from the CDC: “Facts on Screening.” News release, American Cancer Society.