Effect of Radical Prostatectomy on Survival for Men with High-risk Nonmetastatic Prostate Cancer Features Selected According to STAMPEDE Criteria: An EMPaCT Study.

Background and objective: A meta-analysis of two randomized STAMPEDE platform trials revealed that 3 yr of abiraterone acetate in addition to androgen deprivation therapy and radiation therapy significantly improved metastasis-free and overall survival (OS) in high-risk nonmetastatic prostate cancer (PCa) and should be considered a new standard of care. The aim of our study was to assess long-term cancer-specific survival (CSS) and OS for surgically treated patients with newly diagnosed nonmetastatic node-negative PCa meeting the STAMPEDE criteria for high risk.

Methods: This was a retrospective, multicenter cohort study of patients with European Association of Urology (EAU) high-risk PCa who underwent radical prostatectomy and extended pelvic lymph node dissection. CSS was assessed using cumulative incidence curves and the Kaplan-Meier method was used to evaluate OS. We used a Fine and Gray model to evaluate the prognostic value of STAMPEDE high-risk factors (SHRFs) for CSS, and a Cox proportional-hazards model to assess the association of SHRFs with OS.

Key findings and limitations: A total of 2994 patients with EAU high-risk PCa were divided into groups with 0, 1, 2, or 3 SHRFs. The 10-yr survival estimates for patients with 0-1 versus 2-3 SHRFs were 95% versus 82% for CSS and 81% versus 64% for OS (both p < 0.0001). In comparison to patients with 0 SHRFs, hazard ratios were 1.2 (p = 0.5), 3.9 (p < 0.0001), and 5.5 (p < 0.0001) for CSS, and 1.1 (p = 0.4), 2.2 (p < 0.0001), and 2.5 (p = 0.0004) for OS for patients with 1, 2, and 3 SHRFs, respectively.

Conclusions and clinical implications: Our results confirm that the STAMPEDE high-risk criteria identify a subgroup of patients with highly aggressive PCa features and adverse long-term oncological outcomes. This population is likely to benefit most from aggressive multimodal treatment. Nevertheless, we have shown for the first time that surgery remains a viable treatment option for patients with STAMPEDE high-risk PCa.

Patient summary: Prostate cancer that meets the high-risk definitions from the STAMPEDE trial is an aggressive type of cancer. Our results for long-term cancer control outcomes indicate that surgery is a viable option for the subgroup of patients with this type of prostate cancer.