Objectives: Gleason score 4+3 prostate cancer is associated with worse clinicopathologic outcomes than is Gleason score 3+4. Whether the increased risk associated with Gleason score 4+3 disease is equivalent to that of Gleason score 4+4 or greater is unclear.
Methods: We reviewed the data from two separate cohorts pulled from the Shared Equal Access Regional Cancer Hospital database. The first consisted of 374 men with biopsy Gleason score 3+4 or greater disease and the second of 636 men with radical prostatectomy (RP) Gleason score 3+4 or greater disease. We estimated the odds ratios of unfavorable surgical pathologic findings for the biopsy Gleason score categories using logistic regression analysis. Using a Cox proportional hazards regression model, we estimated the relative risk of biochemical progression associated with each biopsy and RP Gleason score category.
Results: In the biopsy Gleason score cohort, a Gleason score of 4+3 was associated with an increased risk of extracapsular extension (P = 0.01) and seminal vesicle invasion (P <0.001) relative to a biopsy Gleason score of 3+4. A biopsy Gleason score of 4+3 was associated with a similar risk of adverse pathologic findings relative to a biopsy Gleason score of 4+4 or greater (all P >0.10), except for higher grade pathologic tumors among men with a biopsy Gleason score of 4+4 or more (P = 0.001). After adjusting for multiple clinical characteristics, a biopsy Gleason score of 4+3 was associated with an increased recurrence risk relative to a biopsy Gleason score of 3+4 (P = 0.001), but a similar progression risk as that for a biopsy Gleason score of 4+4 or more (P = 0.53). In the RP Gleason cohort, and after adjustment for multiple clinicopathologic features, an RP Gleason score of 4+3 was associated with increased progression risk relative to an RP Gleason score of 3+4 (P = 0.03), but similar progression risk as that for an RP Gleason score of 4+4 or more (P = 0.24).
Conclusions: In a multicenter database using pooled data from multiple pathologists, Gleason scores 4+3 and 4+4 or more exhibited similar clinicopathologic outcomes.