PROSTATE CANCER . . . SCREENING WORKS

There is striking new evidence that the standard blood test for prostate cancer is a good predictor of which men will develop it, according to a new study in Wednesday's issue of The Journal of the American Medical Association. Researchers say the blood test predicted almost three-quarters of the malignancies that developed within four years among thousands of middle-age and elderly men. Just as important, the test had a low rate of false positives, 9 percent. That means that the test will steer most patients away from unnecessary surgery.Many men with benign or slow-growing tumors decline surgery, since it may not lengthen their lives, but it often causes such unpleasant consequences as incontinence and impotence.