African-American Men with Gleason Score 3+3=6 Prostate Cancer Produce Less Prostate Specific Antigen than Caucasian Men: A Potential Impact on Active Surveillance.
OBJECTIVE
We assess the difference in prostate specific antigen production between African-American and Caucasian men with Gleason score 3+3=6 prostate cancer.


METHODS
We measured tumor volume in 414 consecutive radical prostatectomies from men with National Comprehensive Cancer Network(®) low risk prostate cancer (348 Caucasian, 66 African-American) who had Gleason score 3+3=6 disease at radical prostatectomy. We then compared clinical presentation, pathological findings, prostate specific antigen, prostate specific antigen density and prostate specific antigen mass (an absolute amount of prostate specific antigen in patient's circulation) between African-American and Caucasian men. The t-test and Wilcoxon rank sum were used for comparison of means.


RESULTS
African-American and Caucasian men had similar clinical findings based on age, body mass index and prostate specific antigen. There were no statistically significant differences between the dominant tumor nodule volume and total tumor volume (mean 0.712 vs 0.665 cm(3), p=0.695) between African-American and Caucasian men. Prostates were heavier in African-American men (mean 55.4 vs 46.3 gm, p <0.03). Despite the significantly greater weight of benign prostate tissue contributing to prostate specific antigen in African-American men, prostate specific antigen mass was not different from that of Caucasian men (mean 0.55 vs 0.558 μg, p=0.95). Prostate specific antigen density was significantly less in African-American men due to larger prostates (mean 0.09 vs 0.105, p <0.02).


CONCLUSIONS
African-American men with Gleason score 3+3=6 prostate cancer produce less prostate specific antigen than Caucasian men. African-American and Caucasian men had equal serum prostate specific antigen and prostate specific antigen mass despite significantly larger prostates in African-American men with all other parameters, particularly total tumor volume, being the same. This finding has practical implications in T1c cases diagnosed with prostate cancer due to prostate specific antigen screening. Lowering the prostate specific antigen density threshold in African-American men may account for this disparity, particularly in selecting patients for active surveillance programs.
Department of Pathology, University of Miami Miller School of Medicine, Miami, Florida; Department of Urology, University of Miami Miller School of Medicine, Miami, Florida. Electronic address: o.kryvenko@med.miami.edu.
Oleksandr N
ON
Kryvenko
Department of Urology, University of Miami Miller School of Medicine, Miami, Florida; Department of Biostatistics, University of Miami Miller School of Medicine, Miami, Florida.
Raymond
R
Balise
Department of Urology, University of Miami Miller School of Medicine, Miami, Florida.
Nachiketh
N
Soodana Prakash
Departments of Pathology, Urology and Oncology, The Johns Hopkins Medical Institutions, Baltimore, Maryland.
Jonathan I
JI
Epstein
D001741:Black or African American; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009929:Organ Size; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000208:ethnology* / Q000473:pathology / Q000601:surgery; D047368:Tumor Burden; D014481:United States; D044465:White People
D017430:Prostate-Specific Antigen
African Americans; European continental ancestry group; neoplasm grading; prostate-specific antigen; prostatic neoplasms