A Tertiary Gleason Pattern in the Prostatectomy Specimen and its Association with Adverse Outcome after Radical Prostatectomy

Abstract

The prognostic significance of a tertiary Gleason pattern in the radical prostatectomy specimen is controversial. We tested the impact of a tertiary Gleason pattern on adverse histopathological features and biochemical recurrence rates after radical prostatectomy. We assessed data on 11,226 consecutive patients treated with radical prostatectomy at our institution between June 2007 and February 2013. We compared 2,396 patients with (22.4%) and 8,260 without (77.5%) a tertiary Gleason pattern for adverse histopathological features (extraprostatic extension, seminal vesicle invasion, positive surgical margins and lymph node invasion) using the chi-square test. The effect of a tertiary Gleason pattern on biochemical recurrence was tested in univariable and multivariable models. Subanalyses were then done for different radical prostatectomy Gleason groups (6 or less, 3 + 4 and 4 + 3). A tertiary Gleason pattern was statistically significantly associated with all evaluated histopathological parameters (each p <0.001). It was an independent predictor of biochemical recurrence (HR 1.43, p <0.001). On subanalysis only a tertiary Gleason pattern independently predicted biochemical recurrence in the patient cohort with a radical prostatectomy Gleason score of 3 + 4 and 4 + 3. However, it failed to attain independent predictor status in patients with a radical prostatectomy Gleason score of 6 or less. A tertiary Gleason pattern is a significant and independent predictor of biochemical recurrence after radical prostatectomy with the strongest prognostic effect in cases with Gleason scores 3 + 4 and 4 + 3. Therefore, a tertiary Gleason pattern should be recorded in the pathological report.