Study Backs Lower PSA Threshold for Black Men

by Will Boggs | Reuters Health | 08.09.2006

NEW YORK - African-American men with early nonpalpable prostate cancer have greater tumor volume than white men with similar prostate specific antigen (PSA) levels, a study shows. This suggests that the threshold for PSA should be lowered in black men.

The widely used PSA blood test is used to look for early signs of prostate cancer. The traditional PSA cut off value is 4 ng/mL.

Based on the current findings, this value should be lowered to 2.5 ng/mL in African-American men "to increase the likelihood of finding cancers that are highly curable," Dr. Curtis A. Pettaway from The University of Texas M. D. Anderson Cancer Center, Houston, Texas told Reuters Health.

The lower cut off value is especially important in African-American men less than 65 years of age and otherwise healthy, Pettaway said.

He and colleagues investigated whether there are pathologic differences by race in men with nonpalpable prostate cancer detected by elevated serum PSA levels alone.

They found that African-American men had higher Gleason scores -- a measure of tumor aggressiveness -- than white men did, despite having similar PSA levels and preoperative prostate biopsy scores.

The Gleason score was upgraded after prostatectomy for 49 percent of the African-American men, compared to only 26 percent of white men.

On average, specimens from African-American men had higher total tumor volumes and higher tumor volumes within given PSA strata than did specimens from white men.

The detection of higher tumor volumes in African-American men despite adjusting for serum PSA level suggests that, even in men with early disease, "the opportunity for cure after surgery may be lower among African-American patients if the same serum PSA threshold for biopsy is used for all races," the investigators explain.

"African-American men should be educated about prostate cancer and should consider getting tested beginning at age 40," Pettaway advised.

SOURCE: Cancer July 1, 2006.

Copyright 2006 Reuters Health