Why Cancer Screening Isn’t Always a Good Idea Cancer screening sounds like the kind of the thing we should all be behind — “Go out there and get tested!” And some screenings, such as pap smears and colonoscopies, are indeed a great way to catch cancers and stop them before they turn deadly. But the wrong kind of cancer screening can actually do more harm than good. Last week, a panel of experts convened by the federal government suggested that, for men 75 and older, the risks of prostate cancer screening outweigh the benefits. Prostate cancer is often a slow-growing disease that doesn’t wind up causing any problems. So screening often leads to treatments (and side effects) for conditions that wouldn’t have caused any harm if they’d been left alone. For older men, the panel concluded, these risks outweigh the benefits of catching tumors that would have caused health problems — including death — if left alone. But as this morning’s New York Times reminds us, it can be difficult to communicate the subtleties of this message. “We’re uncomfortable with the notion that some screening tests work and others don’t,” Peter Bach of Memorial Sloan-Kettering tells the NYT. “That seems mystifying to people.” In Japan, the NYT notes, a screening program for neuroblastoma in infants was abandoned after it became clear the program wasn’t saving lives, but was causing risky treatments of tumors that weren’t life-threatening. Screening smokers for lung cancer is another one that sounds good but remains unproved. And the risk-benefit balance for screening middle-aged men for prostate cancer remains unclear, the panel said last week. Some clarity on that question should be coming soon, though, when the evidence from a huge, federally funded trial is reported.