Objective: We have studied the occurrence and nature of prostate cancer in 330 African American patients with respect to its frequency of occurrence, the prevalence of high grade cancers (Gleason score ≥7), distribution of prostate specific antigen (PSA) levels, whether serum PSA levels correlate with Gleason scores, and whether tumor grade correlates with tumor extension and/or metastasis.
Methods: We reviewed the medical charts of patients at the University Hospital of SUNY Downstate Medical Center for whom prostate biopsies or excisions were performed (2015-2019). We then computed the prevalence of prostate cancer and high grade tumors. To determine if there was a quantitative relationship between PSA and Gleason score, we used linear regression analysis. We further used the Fisher exact test to determine if there exists a serum PSA level beyond which the diagnosis of high-grade prostate cancer is definitive.
Results: The prevalence of prostate cancer was high at 75.8%; of these cancers, 70% were found to be high grade. Ninety two percent of PSA values were ≥ 4.0ng/mL; the sensitivity was 94%; the positive predictive value was 80%. There was a poor correlation between PSA and Gleason score (R2=0.1), but almost 30 percent of PSA values were >20 ng/mL, and almost all of these corresponded to high grade tumors (Fisher exact test, p<0.00001, α=0.05). Fifteen cancers extended beyond the capsule or metastasized; all were high grade tumors.
Conclusions: These patients presented with a high frequency of high-grade prostate cancer and elevated PSA values, such that PSA> 20ng/mL are virtually diagnostic of high-grade prostate cancer. Since the average age, 65, of screening for biopsy in this population is the same as for other demographic groups, screening should be performed at younger ages in this population.
© 2020 by the Association of Clinical Scientists, Inc.