Biopsy Core Features are Poor Predictors of Adverse Pathology in Men with Grade Group 1 Prostate Cancer

Abstract

Active surveillance is often restricted to patients with low risk prostate cancer who have 3 or fewer positive cores. We aimed to identify predictors of adverse pathology results for low risk prostate cancer treated with radical prostatectomy and determine whether a threshold number of positive cores could help the decision process for active surveillance. A total of 3,359 men with low risk prostate cancer underwent radical prostatectomy between January 2000 and August 2016. We analyzed the relationship between biopsy core features and adverse pathology at radical prostatectomy, defined as Grade Group 3 or greater, seminal vesicle invasion or lymph node involvement. Of the 171 cases (5.1%) with adverse pathology findings at radical prostatectomy 144 (4.3%) were upgraded to Grade Group 3 or greater, 31 (0.9%) had seminal vesicle invasion and 15 (0.4%) had lymph node involvement. Prostate specific antigen and patient age were the only predictors of adverse pathology results. There was no significant association with the number of positive cores, the total mm of cancer or the maximum percent of cancer in any core. When we expanded the definition of adverse pathology to include Grade Group 2 and extraprostatic extension, the association between core features and outcome was statistically significant but clinically weak, and with no evidence of threshold effects. There is little basis for excluding patients with otherwise low risk prostate cancer on biopsy from active surveillance based on criteria such as the number of positive cores or the maximum cancer involvement of biopsy cores.