Significance of Number and Localization of Positive Core Biopsies for the Identification of Prostate Cancer Eligible for Active Surveillance.

Objective: Prostate cancer (PCa) patients fulfilling the Epstein criteria for insignificant disease are eligible for the treatment option of active surveillance (AS). Using the combined histological and cytological grading (Gleason/Helpap score), we aimed to investigate the significance of biopsy localization and tumor involvement in core needle biopsies as discriminators for insignificant cancer.

Study design: Primary prostate biopsies of 1,285 patients were analyzed by the combined histological and cytological grading with regard to biopsy localization and tumor involvement per core. For patients diagnosed with pT2a stage PCa, core needle biopsies were further compared with the corresponding radical prostatectomy (RP) specimens.

Results: According to the combined histological and cytological grading, 95% of low-grade PCas (Gleason score 6/2a, prognostic grading group I) presented with a tumor involvement of < 10% in 1 core biopsy, whereas intermediate-grade tumors (prognostic grading group 2) displayed dissimilar tumor localization in 1 or both lobes with higher tumor volume.

Conclusion: Our results indicate that the combined Gleason/Helpap grading may contribute to a more reliable identification of insignificant PCa with the option of AS. Ancillary criteria include the limitation of tumor involvement to < 10% per core, localized in 1 or 2 adjacent biopsies in only 1 lobe. Under this presupposition, > 90% of insignificant carcinomas concurred with low-grade PCa and stage pT2a tumors with negative margins after RP.