Patterns of care for non‐metastatic castration‐resistant prostate cancer: A population‐based study

Abstract

Objectives To describe patterns of practice of PSA testing and imaging for Ontario men receiving continuous ADT for the treatment of non‐metastatic castration‐resistant prostate cancer (nmCRPC). Patients and Methods This was a retrospective, longitudinal, population‐based study of administrative health data from 2008 to 2019. Men 65 years and older receiving continuous androgen deprivation therapy (ADT) with documented CRPC were included. An administrative proxy definition was applied to capture patients with nmCRPC and excluded those with metastatic disease. Patients were indexed upon progression to CRPC and were followed until death or end of study period to assess frequency of monitoring with PSA tests and conventional imaging. A 2‐year look‐back window was used to assess patterns of care leading up to CRPC as well as baseline covariates. Results At a median follow‐up of 40.1 months, 944 patients with nmCRPC were identified. Their median time from initiation of continuous ADT to CRPC was 26.0 months. 60.7% of patients had their PSA measured twice or fewer in the year prior to index, and 70.7% patients did not receive any imaging in the year following progression to CRPC. Throughout the study period, 921/944 (97.6%) patients with CRPC progressed to high‐risk (HR‐CRPC) with PSA doubling time ≤ 10 months, of which more than half received fewer than three PSA tests in the year prior to developing HR‐CRPC, and 30.9% received no imaging in the subsequent year. Conclusion PSA testing and imaging studies are underutilized in a real‐world setting for the management of nmCRPC, including those at high risk of developing metastatic disease. Infrequent monitoring impedes proper risk stratification, disease staging and detection of treatment failure and/or metastases, thereby delaying the necessary treatment intensification with life‐prolonging therapies. Adherence to guideline recommendations and the importance of timely staging should be reinforced to optimize patient outcomes.

Management of patients with advanced prostate cancer—metastatic and/or castration-resistant prostate cancer: Report of the Advanced Prostate Cancer Consensus Conference (APCCC) 2022

“…Treatment was stopped in cases of radiographic progression as per PCWG3 criteria, and investigators were discouraged from changing treatment based solely on rising PSA. In a population-based, patterns-of-care study in nmCRPC, investigators reported that PSA testing and imaging studies were underutilized in real-world settings [52]. The APCCC 2022 panel voted on questions related to how best to use imaging for treatment monitoring in patients with nmCRPC, and when to change treatment.…”

Survival Outcomes by Race and Ethnicity in Veterans With Nonmetastatic Castration-Resistant Prostate Cancer

“…This study’s strengths include the large demographically representative patient population and its context within an equal-access health care system. Most community setting evidence on nmCRPC comes from studies outside the US 54 , 55 , 56 , 57 ; the few US-based studies have focused on patients treated with apalutamide, and thus may not represent all patients with nmCRPC, but only those with high-risk disease. 58 , 59 , 60 Evidence from clinical trials is also subject to the latter weakness, in addition to underrepresenting patients who identify as racial and/or ethnic minorities.…”

Improving the identification of high-risk non-metastatic castration-resistant prostate cancer patients in clinical practice

“…In addition, regular PSA monitoring allows the accurate calculation of PSADT, crucial for prognostic risk assessment in nmCRPC and for making evidence-based decisions toward therapy intensification through the addition of ARIs to the treatment backbone, delaying the development of metastases and improving survival ( 53 , 54 , 58 ). In a recent retrospective study, among 944 nmCRPC patients, 97.6% progressed to high-risk disease with PSADT ≤10 months ( 33 ), highlighting the relevance of this biomarker in the identification of the high-risk nmCRPC state.…”

“…Guidelines recommend PSA testing every 3–4 months and imaging assessment every 3–6 months for patients with PSADT ≤ 10 months and every 6–12 months for those with PSADT >10 months ( 32 ). Despite these recommendations, PSA and imaging assessment are underused in the real-world practice after initiation of continuous ADT, as shown in a large, population-based cohort study where more than half of patients with CRPC who progressed to high-risk nmCRPC received ≤2 PSA tests in the previous year and 31% received no imaging studies in the following 12 months ( 33 ). Infrequent patient monitoring hinders proper disease staging, risk stratification, and detection of treatment failure and/or metastases, with suboptimal patient outcomes.…”