Cancer Screening... or Not

Here's one I don't get. If you're 50 or older, get a check-up every year or two because it will protect you against cancer, says the study in the March 26 issue of Archives of Internal Medicine. No question that the more you see a health-care provider, the more health care you'll be provided with. (Patients who had regular check-ups were more than three times as likely to follow up with a cancer screening.)

But is this a good thing? Only if the cancer screenings that result from these check-ups "the study focused on screening for breast, prostate and colon cancer "are themselves worthwhile. That's the rub: for a number of cancers, the impact of cancer screening on reducing cancer mortality remains very much unproved. Last year, another study threw cold water on the popular prostate specific antigen (PSA) test for prostate cancer: published in the Archives of Internal Medicine, it found that PSA screening doesn't improve a man's chance of surviving prostate cancer. And earlier this month, the Journal of the American Medical Association published a study finding that CT screening for lung cancer found lots more cancers that would otherwise have escaped notice, but produced no decline in lung-cancer deaths.

How can this be? Part of the reason is that many tumors are so "indolent," or slow to grow, that they can stick around in an organ for decades without hurting you. Screenings that detect indolent cancers don't save anyone's life because the cancer wouldn't have done them in even if remained undetected.

For colon cancer, the fecal occult blood test does decrease the risk of dying of this cancer. The evidence is less persuasive for colonoscopy and sigmoidoscopy. Both pick up polyps earlier, but not all polyps become life-threatening cancers. So before we celebrate yet another way to sends millions of people for cancer screening, the medical establishment would do well to take a good hard look at whether it's really doing what it should to "save lives."