Multicentre, prospective study on local treatment of metastatic prostate cancer (LoMP study)

Abstract

Objectives: To investigate the role of cytoreductive radical prostatectomy in addition to standard of care for patients with newly diagnosed metastatic prostate cancer.

Materials and methods: This multicentre, prospective study included asymptomatic patients from 2014 to 2018 (NCT02138721). Cytoreductive radical prostatectomy was offered to all fit patients with resectable tumours, resulting in 40 patients. Standard of care was administered to 40 patients who were ineligible or unwilling to undergo surgery. The primary endpoint was castration resistant cancer-free survival at the time point of ≥50% events. The secondary endpoint was local event-free survival. Kaplan-Meier and Cox regression analyses with propensity-score analysis were applied.

Results: After a median (quartiles) follow-up of 35 (24-47) months, 42 patients became castration-resistant or died. The median castration resistant cancer-free survival was 53 (95% confidence interval [CI] 14-92) vs 21 (95% CI 15-27) months for cytoreductive radical prostatectomy compared to standard of care (P = 0.017). The 3-year estimates for local event-free survival were 83% (95% CI 71-95) vs 59% (95% CI 51-67) for cytoreductive radical prostatectomy compared to standard of care (P = 0.012). However, treatment group showed no significance in the multivariable models for castration resistant cancer-free survival (P = 0.5) or local event-free survival (P = 0.3), adjusted for propensity-score analysis. Complications were similar to the non-metastatic setting. Patients undergoing surgery were younger, with lower baseline prostate-specific antigen levels, alkaline phosphatase levels and metastatic burden.

Conclusion: The present LoMP study was unable to show a difference between the two inclusion groups regarding castration resistant cancer-free survival for asymptomatic patients with newly diagnosed metastatic prostate cancer. These results validate previous evidence that, in well-selected and informed patients, cytoreductive radical prostatectomy is feasible and safe, with corresponding continence rates compared to the non-metastatic, high-risk setting. Whether cytoreductive radical prostatectomy could be a valuable option to achieve good local palliation needs to be further researched. Overall, the role of cytoreductive radical prostatectomy needs to be further explored in randomized studies to correct for potential bias.

Keywords: #PCSM; #ProstateCancer; cytoreduction; hormone-naïve; metastasis; newly diagnosed; progression-free survival; prostatectomy; prostatic neoplasms.