Significance of tertiary Gleason pattern 5 in patients with Gleason score 7 after radical prostatectomy: a retrospective cohort study

PURPOSE: To evaluate the association between tertiary Gleason pattern 5 (TGP5) and biochemical recurrence (BCR) in patients with prostate cancer (PCa) with a Gleason score (GS) of 7 after radical prostatectomy (RP). PATIENTS AND METHODS: This retrospective study identified 350 patients who received RP and were graded as GS 7 (3+4 or 4+3) at the West China Hospital from January 2009 to December 2017. Initially, the patients were divided into two groups, TGP5 absence and TGP5 presence, independent of Gleason score. We further stratified the patients by adding the Gleason score into four groups: GS 3+4, GS 3+4/TGP5, GS 4+3, and GS 4+3/TGP5. Cox proportional-hazards models were used to evaluate the association between the status of TGP5 and BCR after adjusting for the confounding factors. RESULTS: The risk of BCR was significantly higher in patients with TGP5 when compared to patients without TGP5 (P=0.04, HR=2.17 95%, Cl: 1.03–4.59). For patients with primary Gleason pattern 4, the risk of BCR for patients with Gleason 4+3/TGP5 was statistically significantly higher than Gleason 4+3 (P=0.04, HR=2.45, 95% Cl: 1.04–5.76). CONCLUSION: The TGP5 in patients with GS 7 had strong association with the risk of BCR and was an independent predictor for BCR. Further research on larger data sets is needed to confirm these findings.