A Real World Observational Study Characterizing Patients With Advanced Prostate Cancer Treated With or Without Androgen Receptor-Pathway-Inhibitor Therapies in Alberta, Canada.

Background: Data are needed to improve the current understanding of clinical management and characteristics of patients with advanced prostate cancer (PC) treated with androgen receptor pathway inhibition (ARPI) therapy.

Methods: This retrospective cohort study using real-world, population-level data from Alberta, Canada included all individuals diagnosed in 2017-2020 with de novo metastatic castration-sensitive PC (mCSPC) or nonmetastatic castration-resistant PC (nmCRPC) who initiated androgen deprivation therapy (ADT). For mCSPC, patients were classified as ARPI-exposed if they received an ARPI within 180 days of initiating ADT, while patients with nmCRPC were classified as ARPI-exposed if they received an ARPI within 2 years of diagnosis.

Results: This study included 976 patients with mCSPC and 233 with nmCRPC of which 33.5% and 25.3% received an ARPI, respectively. The proportion of patients with mCSPC treated with an ARPI increased considerably for patients diagnosed in 2020 compared to 2017 (56.2% vs. 6.0%). In contrast, the use of ARPI to treat nmCRPC only increased marginally from 2017 to 2019/2020 (19.7% vs. 28.9%). Patients with mHSPC who were ARPI-exposed had longer median survival than patients who were ARPI-naive (38.47 (95% CI = 32.84-NA) vs. 34.19 (95% CI = 33.33-38.83; P = .03)), with a higher proportion of patients surviving to 2-years. For nmCRPC, survival was similar between ARPI-exposed and ARPI-naive. In multivariable analyses, receiving ARPI for mCSPC was associated with younger patient age, more recent diagnoses, fewer comorbidities, a higher number of metastatic sites, referral to a medical oncologist as well as receiving surgery and radiation before ADT. Receiving ARPI for nmCRPC was associated with referral to a medical oncologist, younger age, and more recent diagnoses.

Conclusions: Outcome analyses in this population suggest a continued unmet clinical need and complex clinical management pathways. Given that treatment pathways have evolved considerably, continued follow-up to understand the impact of these advancements on patient outcomes are warranted.