Presentation Authors: Ryuji Matsumoto*, Satoru Maruyama, Jun Furumido, Haruka Miyata, Hiroshi Kikuchi, Takahiro Osawa, Takashige Abe, Nobuo Shinohara, Sapporo, Japan
Introduction: The guidelines of the National Comprehensive Cancer Network recommend radiation therapy plus androgen deprivation therapy (ADT) with category 1 evidence for high-risk localized prostate cancer (HR-LPCa) in patients with a life expectancy of at least 5 years. Radical prostatectomy (RP) plus pelvic lymph node dissection can be considered as an acceptable initial therapy in young and healthy patients. However, to our knowledge, no randomized study at a single center has assessed the therapy that is optimal for disease control in patients with HR-LPCa. In this study, we compared the long-term oncological outcomes of RP and intensity-modulated radiation therapy (IMRT) for HR-LPCa at our institution using a propensity score-matched analysis.
Methods: We retrospectively reviewed 62 patients with HR-LPCa who underwent RP and 107 patients who received IMRT between 1999 and 2011. After adjusting for age, prostate-specific antigen (PSA) level, biopsy Gleason score, and clinical tumor (T)-stage using a propensity score-matched analysis, the rates of castration-resistant prostate cancer-free (CRPC-F), cancer-specific survival (CSS), and overall survival (OS) were compared between the RP and IMRT groups using Kaplan-Meier analysis.
Results: After propensity score matching, 52 patients were assigned to each of the study groups, and age, initial PSA level, biopsy Gleason score, and clinical T-stage were matched exactly. The median follow-up durations in the RP and IMRT groups were 105 and 97 months, respectively. ADT was administered as a combination therapy to 27% and 77% of patients in the RP and IMRT groups, respectively. The 10-year CSS and OS rates were not significantly different between the RP and IMRT groups (CSS rate, 92.6% and 97.9%, respectively; p = 0.519 and OS rate, 88.6% and 91.6%, respectively; p = 0.635). The 10-year CRPC-F rate was not different between the RP and IMRT groups (16.0% and 16.0%, respectively); however, the 13-year CRPC-F rate was significantly higher in the RP group than in the IMRT group (58.9% and 16.0%, respectively; p = 0.038).
Conclusions: Long-term survival outcomes are not different between RP and IMRT. However, in late stages, RP may be superior to IMRT with respect to CRPC-F survival.