Prostate Cancer Specific Mortality and Gleason 7 Disease Differences in Prostate Cancer Outcomes Between Cases With Gleason 4+3 and Gleason 3+4 Tumors in a Population Based Cohort

Purpose: Reports of biochemical recurrence after prostate cancer primary therapy show differences between Gleason 4 + 3 and 3 + 4 tumors. To our knowledge these findings have not been explored for prostate cancer specific mortality. In this population based cohort we determined prostate cancer outcomes at different Gleason scores, particularly the different Gleason 7 patterns. Materials and Methods: Men 40 to 64 years old who were diagnosed with prostate cancer between 1993 and 1996 in King County, Washington comprised the cohort. Recurrence/progression was determined by followup survey and medical record review. Mortality and cause of death were obtained from the Seattle-Puget Sound Surveillance, Epidemiology and End Results registry. HRs for outcomes were determined by Cox proportional hazards regression analysis. Results: In 753 men with prostate cancer 65 prostate cancer specific deaths occurred during a median followup of 13.2 years. The 10-year prostate cancer specific survival rate for Gleason 6 or less, 3 + 4, 4 + 3 and 8-10 disease was 98.4%, 92.1%, 76.5% and 69.9%, respectively. Compared to patients with Gleason 3 + 4 disease those with Gleason 4 + 3 tumors were at increased risk for prostate cancer specific mortality in the unadjusted and multivariate models (HR 2.80, 95% CI 1.26-6.18 and HR 2.12, 95% CI 0.87-5.17, respectively). In men undergoing curative therapy with radical prostatectomy or radiation therapy there was an increased risk of recurrence/progression (HR 2.10, 95% CI 1.08-4.08) and prostate cancer specific mortality (HR 3.17, 95% CI 1.04-9.67) in those with Gleason 4 + 3 vs 3 + 4 tumors in the multivariate models. No difference in prostate cancer specific mortality was seen between Gleason 4 + 3 and 8-10 tumors. Conclusions: Gleason 7 prostate cancer shows heterogeneous behavior with Gleason 3 + 4 and 4 + 3 tumors conferring different prostate cancer specific mortality. These data provide important information for counseling patients with Gleason 7 prostate cancer on the natural history of the disease and may inform treatment decisions.