Login to Access Video or Poster Abstract: MP43-10
Sources of Funding: Canary Foundation, Department of Defense (PC130355), and Institute for Prostate Cancer Research

Introduction

Many patients who are on active surveillance (AS) for prostate cancer (PCa) will have surveillance prostate needle biopsies (PNB) without any cancer evident. The prognostic meaning of these biopsies without cancer is unknown. We sought to define the association between negative surveillance PNB and risk of reclassification on AS.

Methods

All men were enrolled in the Canary Prostate Active Surveillance Study (PASS). Men were included if they had Gleason ≤ 3+4 PCa and ? 34% core involvement ratio at diagnosis and an on-study first surveillance PNB within 2 year of diagnosis. Reclassification was defined as an increase in primary or secondary Gleason grade and/or an increase in the ratio of biopsy cores with cancer to ≥ 34%. PNB outcomes were defined as: a) no evidence of cancer on biopsy, b) evidence of cancer on biopsy without reclassification, or c) reclassification.

Results

657 men met inclusion criteria. On first surveillance PNB, 214 (33%) had no cancer, 282 (43%) had cancer but no reclassification, and 161 (25%) reclassified. Of the 496 men who did not reclassify, 313 had a 2nd PNB. On 2nd PNB, 120 (38%) had no cancer, 139 (44%) had cancer but no reclassification, and 54 (17%) reclassified._x000D_ _x000D_ In a multivariate analysis, significant predictors of future reclassification after 1st PNB were no cancer on PNB (HR = 0.50, p = 0.008), serum PSA, prostate size, and BMI (Table). Diagnostic Gleason score, maximum percentage of involved cores, race, T stage, and study site were considered and found to be non-significant. A finding of no cancer on the 2nd PNB was also associated with significantly decreased future reclassification on multivariate analysis (HR = 0.15, p = 0.003), regardless of first PNB result.

Conclusions

Men who have a surveillance PNB with no evidence of cancer are significantly less likely to reclassify on AS in the PASS cohort. These finding have implications for tailoring AS protocols.

Funding

Canary Foundation, Department of Defense (PC130355), and Institute for Prostate Cancer Research