Genetically adjusted prostate-specific antigen values may prevent delayed biopsies in African-American men.

Abstract

To evaluate whether genetic correction using the genetic variants prostate-specific antigen (PSA)-single nucleotide polymorphisms (SNPs) could reduce potentially unnecessary and/or delayed biopsies in African-American men. We compared the genotypes of four PSA-SNPs between 964 Caucasian and 363 African-American men without known prostate cancer (PCa). We adjusted the PSA values based on an individual's PSA-SNP carrier status, and calculated the percentage of men that would meet commonly used PSA thresholds for biopsy (≥ 2.5 or ≥ 4.0 ng/mL) before and after genetic correction. Potentially unnecessary and delayed biopsies were defined as those men who were below and above the biopsy threshold after genetic correction, respectively. Overall, 349 (96.1%) and 354 (97.5%) African-American men had measured PSA levels <2.5 and <4.0 ng/mL. Genetic correction in African-American men did not avoid any potentially unnecessary biopsies, but resulted in a significant (P < 0.001) reduction in potentially delayed biopsies by 2.5% and 3.9%, based on the biopsy threshold level. There are significant differences in the influence of the PSA-SNPs between African-American and Caucasian men without known PCa, as genetic correction resulted in an increased proportion of African-American men crossing the threshold for biopsy. These results raise the question of whether genetic differences in PSA might contribute to delayed PCa diagnosis in African-American men.