Radiation Facility Volume and Survival for Men With Very High-Risk Prostate Cancer Treated with Radiation and Androgen Deprivation Therapy

• Type of Material: Article
• Authors: Nikhil Sebastian, Emory University; Subir Goyal, Emory University; Yuan Liu, Emory University; James R. Janopaul-Naylor, Emory University; Pretesh Patel, Emory University; Vishal Dhere, Emory University; Sheela Hanasoge, Emory University; Joseph Shelton, Emory University; Karen Godette, Emory University; Ashesh Jani, Emory University; Bruce Hershatter, Emory University; Benjamin Fischer-Valuck, Emory University; Sagar Patel, Emory University
• Language: English
• Date: 2023-08-01
• Publisher: JAMA
• Publication Version: Final Published Version
• Copyright Statement: 2023 Sebastian N et al. JAMA Network Open.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1001/jamanetworkopen.2023.27637
• Title of Journal or Parent Work: JAMA network open
• Volume: 6
• Issue: 8
• Start Page: e2327637
• End Page: e2327637
• Grant/Funding Information: Dr S. Patel is supported by the National Cancer Institute (NCI) of the National Institutes of Health (NIH) under award number K12CA237806 from the Winship K12 Clinical Oncology Training Program. This work was supported in part by the Biostatistics and Bioinformatics Shared Resource of Winship Cancer Institute of Emory University and NIH/NCI under award number P30CA138292.
• Keywords: Prostatic Neoplasms; Male; Aged; Androgen Antagonists; Cohort Studies; Humans; Retrospective Studies; Androgens; Risk Factors
• Research Categories: Health Sciences, Oncology; Physics, Radiation

Abstract

Importance: Very high-risk (VHR) prostate cancer is an aggressive substratum of high-risk prostate cancer, characterized by high prostate-specific antigen levels, high Gleason score, and/or advanced T category. Contemporary management paradigms involve advanced molecular imaging and multimodal treatment with intensified prostate-directed or systemic treatment-resources more readily available at high-volume centers. Objective: To examine radiation facility case volume and overall survival (OS) in men with VHR prostate cancer. Design, Setting, and Participants: A retrospective cohort study was performed from November 11, 2022, to March 4, 2023, analyzing data from US facilities reporting to the National Cancer Database. Patients included men diagnosed with nonmetastatic VHR prostate cancer by National Comprehensive Cancer Network criteria (clinical T3b-T4 category, primary Gleason pattern 5, >4 cores with grade group 4-5, and/or 2-3 high-risk features) and treated with curative-intent radiotherapy and androgen deprivation therapy between January 1, 2004, to December 31, 2016. Exposures: Treatment at high- vs low-average cumulative facility volume (ACFV), defined as the total number of prostate radiotherapy cases at an individual patient's treatment facility from 2004 until the year of their diagnosis. The nonlinear association between a continuous ACFV and OS was examined through a Martingale residual plot; an optimal ACFV cutoff was identified that maximized the separation between high vs low ACFV via a bias-adjusted log rank test. Main Outcomes and Measures: Overall survival was assessed between high vs low ACFV using Kaplan-Meier analysis with and without inverse probability score weighted adjustment and multivariable Cox proportional hazards. Results: A total of 25 219 men (median age, 71 [IQR, 64-76] years; 78.7% White) with VHR prostate cancer were identified, 6438 (25.5%) of whom were treated at high ACFV facilities. Median follow-up was 57.4 (95% CI, 56.7-58.1) months. Median OS for patients treated at high ACFV centers was 123.4 (95% CI, 116.6-127.4) months vs 109.0 (95% CI, 106.5-111.2) months at low ACFV centers (P < .001). On multivariable analysis, treatment at a high ACFV center was associated with lower risk of death (hazard ratio, 0.89; 95% CI, 0.84-0.95; P < .001). These results were also significant after inverse probability score weighted-based adjustment. Conclusions and Relevance: In this cohort study of patients with VHR prostate cancer who underwent definitive radiotherapy and androgen deprivation therapy, facility case volume was independently associated with longer OS. Further studies are needed to identify which factors unique to high-volume centers may be responsible for this benefit.