Percent Free PSA Questioned for Cancer Diagnosis
Among younger men, measure added no benefit to total prostate specific antigen in diagnosing prostate cancer
FRIDAY, Dec. 28 (HealthDay News) -- Using percent free prostate specific antigen (PSA) added no benefit in diagnosing prostate cancer compared to using total PSA, according to research published in the January issue of the Journal of Urology.
In Gab Jeong and Kang Hyun Lee of the National Cancer Center in Goyang, Korea, analyzed data from 1,528 men with serum PSA of 4.0 to 10.0 ng/mL and no suspicion of cancer on a digital rectal exam, who underwent biopsy. The report indicates that 17 percent had a positive biopsy, and the remainder were negative.
The investigators found that percent free PSA was no better than total PSA for differentiating prostate cancer in men with a palpably benign gland and a PSA level in the so-called "gray zone." Though it did add modestly to the diagnostic performance in older men (over 65 years), percent free PSA offered no added benefit in the younger group, who are most likely to be helped by early detection. Percent free PSA was calculated as the ratio of free to total PSA multiplied by 100.
"Our results show that the diagnostic performance of percent free PSA for detecting prostate cancer, which was previously shown to have better specificity than total PSA in other Asian countries, needs further evaluation in prospective large-scale studies," the authors conclude.