117 - Outcomes Following Radiation Therapy and Radical Prostatectomy in Patients with High Risk Prostate Cancer in a Similar Access System

03:00pm - 03:10pm PT

Room 24

Presenter(s)

Abhishek Kumar, MD, MAS - The Oncology Institute of Hope and Innovation, Cerritos, CA

A. Kumar, A. Skipper, D. LaBella, M. C. Snider, S. Acklin, J. K. Salama, and M. J. Boyer; Department of Radiation Oncology, Duke University Medical Center, Durham, NC

Purpose/Objective(s):

There have been no completed randomized trials comparing radical prostatectomy (RP) to radiation therapy (RT) in patients with high-risk prostate cancer (HR-PC) in the modern era. The current optimal treatment strategy for patients with HR-PC is unclear. We compared oncologic outcomes in HR-PC patients treated with primary surgery and radiation in a similar access system.

Materials/Methods: Patients with HR-PC, diagnosed between 2000-2021, and having a prostate MRI prior to RP or RT were identified from the Veterans Affairs Prostate Data Core. HR-PC included patients with prostate specific antigen (PSA) > 20, grade group 4-5 disease, or prostate MRI findings consistent with extraprostatic extension (MRI-EPE). The primary outcome was metastasis free survival (MFS). A multivariable Fine-Gray competing-risks regression was used to compare treatments with MFS as a primary endpoint.

Results: 899 patients were included; 521 (58%) patients received RT and 378 (42%) patients received RP. Most patients had an MRI prostate after 2016 (85%). Patients receiving RT were older than patients receiving RP (68 vs. 65 years, p<0.01), and more likely to be Black (44% vs. 36%, p=0.02). Patients receiving RT and RP had similar rates of palpable disease (29% vs. 29%, p=0.92), MRI-EPE (52% vs. 53%, p=0.76), and grade group 4-5 disease (58% vs. 54%, p=0.18). Patients receiving RP had a slightly higher median PSA than patients receiving RT (8.6 vs. 7.8, p<0.01). Median follow-up time was 5.1 years. The 5-year cumulative incidence of metastasis for the cohort was 9% (95% CI 7-10%). On multivariable analysis, compared to patients receiving RT, patients with RP had worse MFS (HR 2.74, 95% CI 1.74-4.31, p<0.01).

Conclusion:

In this cohort of patients with HR-PC treated a similar access system with modern staging, those treated with RP had significantly worse MFS than patients receiving RT. If validated in other cohorts, these data could inform HR-PC patients in making therapeutic choices.