Long-Term Oncological Outcomes of Robot-Assisted Radical Prostatectomy for Clinically Localized Grade Groups 4 and 5 Prostate Cancers Diagnosed on Prostate Biopsy.

[OBJECTIVES] This study aimed to investigate the long-term oncological outcomes of Grade Group (GG) 4 and 5 Prostate Cancer (PCa) diagnosed by prostate biopsy who underwent robotic-assisted radical prostatectomy (RARP).

[METHODS] We retrospectively reviewed our database for those who had clinically localized GG 4 and 5 PCa discovered on prostate biopsy who underwent RARP before January 1, 2018. Demographic and clinical data was collected. Primary outcomes included overall survival (OS) and PCa-specific survival (CSS). Secondary outcomes covered biochemical recurrence-free survival (BCR-FS), need for adjuvant or salvage radiotherapy (aRT/sRT), and final specimen pathological features. Kaplan-Meier analyses assessed 5-, 10-, and 15-year OS and BCR-FS.

[RESULTS] 98 patients met our inclusion criteria, with a median age of 63.7 years (IQR: 59.7-69.3) and a median preoperative PSA level of 6.9 ng/mL (IQR: 4.9-10.9). Most patients were GG 4 (77.6%), and 22.4% were GG 5. Pathology at prostatectomy revealed the following ISUP Grade Groups: 19 patients (19.4%) with Grade Group 2, 36 (36.7%) with Grade Group 3, 27 (27.6%) with Grade Group 4, and 16 (16.3%) with Grade Group 5. 64.2% had pT3 (or greater?) disease, 21.4% with pN+, and 22.4% with positive margins. 26.5% of patients received post-RARP radiotherapy (14.3% adjuvant, 12.5% salvage). After a median follow-up of 132 months, 12 deaths occurred (none from prostate cancer; CSS = 100%]). OS estimates were 95% at 5 years, 88% at 10 years, and 86% at 15 years. The estimated BCRFS rates were 90%, 80%, and 78% at 5, 10, and 15 years respectively.

[CONCLUSIONS] In our cohort, RARP for clinically localized GG 4 and 5 PCa discovered on prostate biopsy achieved high OS, CSS, and BCFRS rates with mostly single-modality treatment. RARP remains a valid first-line treatment for clinically localized GG 4 and 5 PCa.