Abnormal PSA test should be repeated before prostate biopsy

Prostate-specific antigen (PSA) levels vary significantly, suggesting that abnormal tests should be repeated before ordering a prostate biopsy, according to a report in the May 28th Journal of the American Medical Association.

PSA testing increases the rate of prostate cancer detection, the authors explain, but three quarters of men with moderately elevated PSA levels (between 4 and 10 ng/mL) have negative biopsy results.Dr. James Eastham from Memorial Sloan-Kettering Cancer Center in New York and associates in the Polyp Prevention Trial Study Group measured total and free PSA levels in serial blood samples obtained from 972 men during a 4-year colon polyp prevention trial to study natural variation in PSA levels.Using any of the common PSA thresholds, 37% of men would have met at least one criterion for an abnormal PSA test result during the study, the authors report.Among men with a normal baseline PSA level, 12% experienced a subsequent PSA level above 4 ng/mL and 17% subsequently had a PSA level above 2.5 ng/mL, the report indicates, whereas 9% and 10%, respectively, met age-specific and free-PSA ratio criteria for an abnormal result.Thirty percent of men who initially had a PSA level above 4 ng/mL had a PSA level below 4 ng/mL at the next visit, the researchers note, and 26% of men with an initial PSA level above 2.5 ng/mL had a normal level at their next visit.Forty-four percent of men with a PSA level above 4 ng/mL and 40% of men with a PSA level above 2.5 ng/mL had normal PSA values at some subsequent visit, the results indicate, and 65% to 83% of those who returned to normal still had a normal PSA level at their next annual evaluation.’Fluctuations of PSA above and below normal are commonplace,’ Dr. Eastham told Reuters Health. ‘No patient should be referred for a prostate biopsy based on a single elevated PSA test.”Waiting to repeat/confirm the PSA test in 4 to 6 weeks is recommended,’ Dr. Eastham said. ‘The goal of such a practice is to reduce the number of unnecessary prostate biopsies.”There are obviously exceptions to this rule,’ Dr. Eastham added. ‘If someone has an abnormal digital rectal exam, then that would be an indication to proceed with a biopsy rather than waiting to repeat a PSA test. If there are signs/symptoms of prostatitis (probably a rare situation), then a course of antibiotics/anti-inflammatories may be justified. But, for the vast majority of patients with an elevated PSA and normal exam, a 4 to 6 week period of time seems prudent before confirming the PSA result.'(Source: JAMA 2003;289:2695-2700: Reuters Health: Will Boggs, MD: May 27, 2003: Oncolink)