Debate on screening for cancer is complex

It seemed like a good idea at the time.

In 1984, Japan began screening the urine of 6-month-old infants for neuroblastoma, the most common type of solid tumor in young children. The test was simple and could show signs of cancer long before clinical symptoms arose.

Hundreds of infants went through the ordeal of diagnosis and treatment, but it didn't reduce the number of tumors found later, including deadly ones. Almost none of the tumors caught by screening turned out to be dangerous — and more of the screened children died of complications from surgery and chemotherapy than from the cancer itself.

In 2004, health officials ended the program.

The United States is grappling with the same type of problem today. After decades of focus on the upside of cancer screening, public health experts are re-evaluating the wisdom of administering routine cancer screening tests to millions of asymptomatic people.

Although screening certainly saves lives, recent studies make it clear that it also leads to biopsies, surgeries, chemo and radiation — even some deaths — that otherwise would not have occurred.

That screening has a downside is not easy to accept, as evidenced by the furor over last week's recommendation from the U.S. Preventive Services Task Force that most women wait until 50 to start routine mammograms, and then get them only every other year.

Although the decision was based on new scientific evidence that many more women are harmed than helped by annual tests starting at 40, it swiftly was attacked by physicians and policymakers who said they would ignore it.

The message that we're over-screening for cancer isn't necessarily a welcome one to the American public either.

A whopping 87 percent of U.S. adults believe that routine screening is "almost always a good idea," and 74 percent believe early detection saves lives "most or all of the time," according to a 2004 survey in the Journal of the American Medical Association. Most said they'd continue to get their screening tests even if their doctors advised against it.

Indeed, in the days following release of the task force's recommendations, irate breast cancer survivors lighted up message boards to vent their anger at the notion that their lives were not worth saving.

Complicating matters is that it's easy to identify cancer survivors whose tumors were caught by screening, but it's nearly impossible to put a face on the woman or man who is hurt by over-screening.