Score one against conventional wisdom: Those cancer screening tests for early detection that are constantly urged? Turns out they don't save lives in most cases.Patients may consider them fighting words, but unfortunately, the research backs it up when it comes to most cancers beyond cervical and colorectal. In fact, research shows screening for other cancer types can wind up doing more harm than good. In our summer issue of CURE, Dr. Len Lichtenfeld of the American Cancer Society explained the latest controversy over PSA (short for prostate-specific antigen) screening for prostate cancer. We're taking this subject a step further in our upcoming fall issue, laying out the benefits versus harms, and why in some cases screening doesn't make a difference. As for one of those reasons, contributing writer Laura Beil summed it up this way in the upcoming article: "Screening can fail partly because of the nature of cancer, and the shortcomings of current technology. Because aggressive tumors--the ones you most want to find--tend to grow rapidly, screening is less likely to pick them up. And slow-moving tumors are generally less deadly and may never even clinically manifest during a person's lifetime."It's a complicated (and delicate) subject. So to dig a little deeper, we asked Dr. Barnett S. Kramer, the associate director for disease prevention at the National Institutes of Health, to author the fall issue's Speaking Out column. He writes: "It has been estimated that as many as 50 percent of prostate cancers detected by PSA screening are so slow-growing that they never would have caused any medical problems, had they not been detected by screening."Until the fall issue drops in September, check out recent coverage of the screening debate from the New York Times and Newsweek.