Impact of Biopsy Gleason Upgrading on Biochemical Recurrence and Prediction for Prostate Cancer Aggressiveness Among Obese and African American Men

Abstract

Introduction: Biopsy Gleason grade (BGR) upgrading in radical prostatectomy (RP) specimens is associated with a higher risk of biochemical reoccurrence (BCR). However, research to examine this association in high-risk groups for prostate cancer, such as obese, African-American (AA) and advanced age men is limited. Objectives: To examine whether BGR upgrading is associated with increased risk of biochemical recurrence among obese, AA and older men. Methods: Retrospective analyses of a cohort of 1028 men with low and medium risk of prostate cancer (PCa) (BGR groups 1&2) who underwent RP between 1995- 2012 at the University of Pennsylvania Health System (UPHS, Philadelphia, PA). Association of BGR upgrading and BCR after RP among obese, AA and older men were examined using log rank test and Cox proportional hazards models. Results: In this cohort, there were 251 obese men and 200 AA men. Upgrading from BGR 1 and 2 (low and middle risk PCa, respectively) to RPG≥ 3 (high risk PCa) significantly increased BCR; the log rank test p value for upgraded compared to concordant in both groups was 0.0037 and <0.0001respectively. In low risk PCa group, the log rank P values showed no difference between BGR upgrading and concordance group among obese 0.14, AA 0.07 and older men 0.12. BGR upgrading from both low and middle risk to high risk PCa showed significant difference in BCR compared to concordant group, and was independent of obesity, race and age. The log rank test p values comparing upgrading versus concordant groups among obese, AA and older men were 0.0005, 0.001 and <0.0001 respectively. Conclusions: This study confirmed that BGR upgrading from low and middle risk PCa groups to high risk PCa group increases BCR. Additionally, obesity, AA race and older age are independent risk factors for BCR in low risk PCa group regardless of upgrading. Further studies are warranted to confirm these associations in larger and diverse populations.