Cases Having a Gleason Score 3+4=7 With <5% of Gleason Pattern 4 in Prostate Needle Biopsy Show Similar Failure-free Survival and Adverse Pathology Prevalence to Gleason Score 6 Cases in a Radical Prostatectomy Cohort

Abstract

Recent discussions have suggested expanding the inclusion criteria for active prostate cancer surveillance to include cases with a Gleason score (GS) of 3+4=7. In this study, we examined this proposed use of a limited percent Gleason pattern 4 (%GP4) to identify candidates of active surveillance among 315 patients who underwent radical prostatectomy for prostate cancer with a GS of 6 or 3+4=7 via needle biopsy. The latter cases were divided into 4 groups using highest or overall %GP4 cut-off values of 5% and 10% as determined from prostate needle biopsies. The frequency of adverse pathology and risk of biochemical recurrence were compared between the GS 6 and both GS 3+4=7 groups. Adverse pathology was defined as a GS 4+3=7 or higher, pT3b staging or positive lymph node metastasis. Notably, the Gleason pattern 4 <5% and GS 6 groups did not differ significantly in terms of the frequency of adverse pathology and risk of biochemical recurrence by the highest method. However, other highest Gleason pattern 4 categories had significantly higher frequencies and risks. Using the overall method, even the Gleason pattern 4 <5% group had a significantly higher frequency of adverse pathology and risk of biochemical recurrence relative to the GS 6 group. In conclusion, our findings suggest that patients with a GS 3+4=7 on biopsy with a highest %GP4 <5% are similar candidates for active surveillance to men with GS 6 cancers.