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

Objective 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. Subjects and Methods 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. Results 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. Conclusions 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.