Does surgery benefit patients with oligometastatic or metastatic prostate cancer? – A retrospective cohort study and meta‐analysis

BACKGROUND: To evaluate long-term oncological outcomes of radical prostatectomy (RP) plus androgen deprivation therapy (ADT) in oligometastatic prostate cancer (PCa) patients. METHODS: Our study included oligometastatic PCa patients hospitalized between January 1, 2010 and December 31, 2015, who received ADT with or without RP. We evaluated survival by employing Kaplan-Meier methods, with log-rank tests and univariate and multivariate Cox regression analyses. A meta-analysis of previously published studies was additionally performed. RESULTS: The median follow-up times of both groups were 68.4 months (interquartile range = 56.5-85.0). In this cohort study, significant statistical difference in preoperative total prostate-specific antigen (tPSA; p = .121), clinical T stage (p = .115), and N stage (p = .394) were not found between the two groups. Meanwhile, the difference in overall survival (OS) between the two groups did not reach statistical significance (p = .649). A significant difference was not observed in castration-resistant prostate cancer (CRPC)-free survival between two groups as well (p = .183). Numbers of metastases might be an independent prognosis factor (p = .05) for OS, and postoperative tPSA is a risk predictor for CRPC-free survival (p = .032). A meta-analysis of four relevant studies demonstrated significant statistical difference in clinical improvement with RP plus ADT over ADT alone in OS survival (p < .001; hazard ratio [HR] = 0.51; 95% confidence interval [CI] = 0.38-0.69) instead of CRPC-free survival (p = .42; HR = 0.86; 95% CI = 0.59-1.24). CONCLUSION: The addition of RP to ADT for the treatment of oligometastatic PCa was associated with an improved OS instead of CRPC-free survival.