Obesity Not an Obstacle for Prostate Specific Antigen Test
Researchers find PSA tests useful in prostate cancer assessment across the range of BMIs
MONDAY, July 20 (HealthDay News) -- A patient's weight does not significantly affect the usefulness of prostate specific antigen (PSA) testing to determine prostate cancer, according to a study in the August issue of the Journal of Urology.
Lionel L. Banez, M.D., of Duke University Medical Center in Durham, N.C., and colleagues analyzed the medical records of 11,705 men comprising three cohorts who had radical prostatectomy between 1988 and 2007 at the Duke Prostate Center, Johns Hopkins Hospital Center, and Veterans Affairs hospitals. To test the hypothesis that PSA tests are of limited usefulness for cancer prognosis in obese men because of hemodilution, the researchers assessed the ability of PSA to predict tumor characteristics and recurrence in several body mass index categories: less than 25 kg/m2 (normal), 25 to 29.9 (overweight), 30 to 34.9 (mildly obese), and 35 or greater (moderately/severely obese).
The researchers found no significant variation in the area under receiver-operating-characteristic curves for the different body mass index categories that affected the prediction of Gleason sum, positive surgical margins, invasion of seminal vesicles, or extracapsular extension. Likewise, no significant difference was discerned in the ability of PSA to predict biochemical recurrence.
"In three cohorts of men treated with radical prostatectomy the ability of preoperative PSA to predict adverse pathological features and post-treatment biochemical recurrence is not significantly affected by obesity," the authors write. "However, adjusting for obesity-related hemodilution may still be required to properly interpret PSA results in men with increased body mass index."
Authors of the study reported financial relationships with the pharmaceutical industry.