Testing Shown to Cut Colon Cancer Deaths

A major study shows for the first time that screening older people yearly with a widely used test can reduce the risk of dying from colon cancer by one-third.

Researchers who conducted the study estimate that giving the $5 fecal blood test to everyone over 50 could prevent 20,000 deaths annually from colon cancer, the nation’s second leading cancer killer after lung cancer.

“We are the first study to have a conclusive result to show that the test is effective for reducing mortality,” said Dr. Jack S. Mandel, who directed the research at the University of Minnesota.

However, experts differed over whether the study is the proof needed to urge everyone over age 50 to get the test yearly, as the American Cancer Society recommends.

At issue is the test’s accuracy in diagnosing colon cancer. Ominous results almost always turn out to be false alarms.

Overall, 10% of those tested are found to have blood in their stools, a possible sign of colon cancer. Fewer than three in 100 of those actually have colon cancer. Yet the 97 others must undergo costly, unpleasant follow-up tests to prove they are cancer free.

Because of the high cost of the follow-up tests to rule out cancer, mass screening of older Americans could cost more than $3 billion a year, according to one estimate.

But in an editorial published with the study in Thursday’s New England Journal of Medicine, Dr. Sidney J. Winawer of Memorial Sloan-Kettering Cancer Center in New York City wrote: “We now have an effective screening method, and I believe we should use it.”

The study, begun in the mid-1970s, was conducted on 46,551 people ages 50 to 80. They were randomly assigned to have the test annually, every other year, or not at all.

During 13 years of follow-up, six of every 1,000 people tested died each year from colon cancer, compared with nine of every 1,000 who did not get tested. Those tested every other year had only a slightly reduced death rate.