Percentage of Positive Biopsy Cores at the Onset of Hormone Therapy for Prostate Cancer: Prognostic Significance

Abstract

Introduction: The percentage of positive prostate biopsy cores (%PBC) has been shown to be a prognostic factor in localized prostate cancer. We hypothesized that it would predict time to hormonal independence and survival in prostate cancer patients treated with androgen deprivation therapy (ADT). Patients and Methods: We used clinical data from 403 men treated with ADT between 1980 and 1999 and focused on a subgroup of 220 patients treated with GnRH analogue. %PBC was defined as the number of positive biopsy cores multiplied by 100 and divided by the total number of biopsy cores. Results: Median %PBC was 83.3% (16.7–100%). Mean follow-up was 57.4 months. Survival at 5 years in men with 83.3% PBC or less was 62.3, 89.1 and 82.6% for recurrence-free, specific and overall survival, respectively, significantly better than that of men with a %PBC of more than 83.3% (32.2, 74.7 and 67.7%, respectively; p < 0.004). Among the factors available in the pretreatment setting, namely age, clinical stage, PSA, Gleason score, bone scan and %PBC, the latter was independently associated with survival in multivariate analysis. Conclusions: %PBC may improve the ability to predict time to hormonal resistance and survival in patients treated with ADT for prostate cancer. This finding warrants further investigation.