Gleason Score 7 Prostate Cancer on Needle Biopsy: Relation of Primary Pattern 3 or 4 to Pathological Stage and Progression After Radical Prostatectomy

Abstract

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