Effect on survival of local treatment in patients with low prostate-specific antigen, high Gleason score prostate cancer: a population-based propensity score-matched analysis.

ABSTRACT

BACKGROUND: Emerging data suggest that in patients with low prostate-specific antigen (PSA) and high Gleason score, prostate cancer (PCa) is more aggressive and more likely to be related to genomic characteristics of neuroendocrinology. However, the evidence for the advantages of local treatment (LT) for these men is lacking. Hence, we investigated survival in men with low-PSA values and high-grade (Gleason score 8-10) PCa according to the treatment of the primary tumor. METHODS: Kaplan-Meier survival analysis was applied to analyze the effects on overall survival (OS) and cancer-specific survival (CSS) according to the different treatments of the primary tumor. Multivariable Cox proportional hazards survival regression analysis calculated the CSS after propensity score matching (PSM) in 2 cohorts according to treatment type. The treatment types included the following (I) LT versus non-LT (NLT) and (II) radical prostatectomy (RP) versus radiotherapy (RT). RESULTS: In the Surveillance, Epidemiology, and End Results (SEER) database [2004-2014], we identified 14,208 patients newly diagnosed with low PSA values (10 ng/mL or less), with a Gleason score 8-10, and cT1-4N0M0 prostate adenocarcinoma. After the first PSM, of the 3,512 PCa patients, 1,576 underwent LT and 1,576 underwent NLT. After the second PSM, of the 792 PCa patients, 396 underwent RP, and 396 underwent RT. The 5- and 10-year OS rates for LT vs. NLT patients were 90% and 73% versus 69% and 39%, respectively, while the 5- and 10-year CSS rates for LT vs. NLT patients were 98% and 94% versus 89% and 79%, respectively. Subsequent multivariate survival analysis showed that LT was associated with lower likelihood of PCa mortality relative to NLT [hazard ratio (HR), 0.19; 95% confidence interval (CI), 0.14-0.26, P<0.001], also in RP versus RT (HR, 0.26; 95% CI, 0.12-0.54, P<0.001). CONCLUSIONS: In patients with low PSA values, Gleason score 8-10, and localized PCa, LT resulted in higher survival compared with NLT. Within LT, RP provided the most benefit relative to RT.