biopsy. Such results are only the tip of the research iceberg as scientists evaluate many improvements. The hunt is on, for instance, for PSA "isoforms"—antigens specifically produced by benign prostatic hyperplasis, not cancerous tissue. Distinguishing PSA molecules of two types could yield a test so precise that false positives caused by enlarged or inflamed prostates could be eliminated.
Despite such prospects, controversy still hovers even as mortality rates fall where PSA screening has been intense and studies show a promising overall track record. The test continues to detect twice as many malignancies of digital exams, with 80 percent of the detected tumors being potentially life-threatening.
Researchers hope that ongoing trials will settle many of the issues. But, until science comes up with a better or improved test, the best diagnostic prostate cancer screen is the all-familiar PSA test.