Gleason score 7 prostate cancer on needle biopsy: relation of primary pattern 3 or 4 to pathological stage and progression after radical prostatectomy

Abstract

Purpose: There have been only a few contradictory publications assessing whether Gleason score 4 + 3 = 7 has a worse prognosis than 3 + 4 = 7 on biopsy material in predicting pathological stage and biochemical recurrence. Older studies predated the use of the modified Gleason grading system established in 2005.

Materials and methods: We retrospectively studied 1,791 cases of Gleason score 7 on prostatic biopsy to determine whether the breakdown of Gleason score 7 into 3 + 4 vs 4 + 3 has prognostic significance in the modern era.

Results: There was no difference in patient age, preoperative serum prostate specific antigen, maximum tumor percent per core or the number of positive cores between Gleason score 3 + 4 = 7 and Gleason score 4 + 3 = 7. Gleason score 4 + 3 = 7 showed an overall correlation with pathological stage (organ confined, focal extraprostatic extension, nonfocal extraprostatic extension, seminal vesicle invasion/lymph node metastases, p = 0.005). On multivariate analysis Gleason score 4 + 3 = 7 (p = 0.03), number of positive cores (p = 0.002), maximum percent of cancer per core (p = 0.006) and preoperative serum prostate specific antigen (p = 0.03) all correlated with pathological stage. Gleason score 4 + 3 = 7 on biopsy was also associated with an increased risk of biochemical progression after radical prostatectomy (p = 0.0001). On multivariate analysis Gleason score 4 + 3 = 7 (p = 0.001), maximum percent of cancer per core (p <0.0001) and preoperative serum prostate specific antigen (p <0.0001) but not number of positive cores correlated with the risk of biochemical progression after radical prostatectomy.

Conclusions: Our study further demonstrates that Gleason score 7 should not be considered a homogenous group for the purposes of disease management and prognosis.