Population-based assessment of treatment patterns for high-risk localized prostate cancer

Abstract

Introduction: High- and very high-risk (H/vHR) localized and locally advanced prostate cancer (LPCa) carry a high burden of distant relapse. In light of emerging data on adjunctive systemic therapy, we aimed to assess present-day, real-world treatment patterns and outcomes among Canadian patients with intermediate-risk (IR) and H/vHR LPCa. Methods: This retrospective, population-based cohort study identified men aged ≥18 years diagnosed with LPCa between 2010 and 2022 in Ontario, Canada. Patients were stratified into IR and H/vHR groups. Baseline patient characteristics and treatment patterns following LPCa diagnosis were described. Clinical outcomes, including median time to mortality, were assessed using Kaplan-Meier analyses. To better characterize androgen deprivation therapy (ADT) exposure, subgroup analyses were performed in patients aged ≥66 years. Results: Among 31 571 eligible patients, 18 365 had IR LPCa and 13 206 had H/vHR LPCa. Within one year from diagnosis, patients with H/vHR were more likely to receive definitive therapy (95.4% vs. 81.5%), with shorter durations between diagnosis and treatment (median 72 days vs. 92 days) compared to patients with IR. Patients with H/vHR demonstrated lower median time to mortality (median 4.9 vs. 5.9 years, p<0.0001). Treatment modalities were comparable between cohorts, with external beam radiation therapy (EBRT), radical prostatectomy (RP), and brachytherapy being the most common. Among patients aged ≥66 years, use of ADT post-RP was limited. Conclusions: Current real-world treatment approaches for H/vHR LPCa emphasize local therapy with surgery and radiotherapy. There are considerable gaps, which may allow improved outcomes through optimized use of systemic therapy.