Men hate the digital rectal examination -- so much so, in fact, that the desire to avoid it may lead them to put off follow-up visits to the doctor after radical prostatectomy. From a medical standpoint, in turn, the rectal exam is only as good as the physician performing it. Similarly, another test often used in follow-up monitoring of prostate cancer patients after surgery, the radionuclide bone scan, is expensive and also may lead to further tests if the findings are inconclusive.

Is there a better way? A Hopkins study led by urologist Charles R. Pound, M.D., found that PSA is such a sensitive marker of prostate cancer that if the PSA is undetectable, men don't need a digital rectal examination or further imaging studies at that time. In other words, they're off the hook. (However, men still need careful follow-up with a PSA test every year.)

In the investigation, scientists studied the medical histories of nearly 2,000 men who underwent radical prostatectomy at Hopkins over a 15-year period -- a remarkable study of more than 10,000 patient- years of follow-up. Of these men, 56 developed a local recurrence of cancer, and 118 developed distant metastases. For some of these men, it took several years for cancer to return -- which is why men need to keep getting regular PSA tests, even several years after surgery -- but no man with an undetectable PSA had evidence of local recurrence or distant metastasis.