AUA2022: BEST POSTERS: Practice Patterns in Management of Hormone-Sensitive Metastatic and Castrate-Resistant Nonmetastatic Prostate Cancer

By: Daniel D. Joyce, MD; Vidit Sharma, MD; Andrew Zganjar, MD; Eugene D. Kwon, MD; R. Jeffrey Karnes, MD | Posted on: 01 Oct 2022

Pfizer contributed to this study in the form of data analysis.

Early efforts to improve survival for patients with advanced prostate cancer were directed toward castrate-resistant disease states. The CHAARTED trial marked the advent of a rapidly evolving landscape for earlier management of newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC).1 The observed overall survival benefit associated with docetaxel use in addition to androgen deprivation therapy (ADT) was the most promising advancement in treatment of mHSPC since Charles Huggins and Clarence Hodges Nobel Prize winning discovery of the benefits of ADT in the 1940s.2 Since the published results of CHAARTED in 2015, 3 additional treatment options have been U.S. Food and Drug Administration approved (apalutamide, enzalutamide, abiraterone)3-5 and further benefit has been demonstrated in combining these treatments. At the same time, similar advantages were observed with use of second-generation antiandrogens (AAs: enzalutamide, apalutamide, and darolutamide) in patients with nonmetastatic castrate-resistant prostate cancer (nmCRPC).6-8 Based on these findings, AUA guidelines now recommend the use of these novel treatments in addition to ADT for patients with mHSPC and nmCRPC.9 While real-world practice patterns in patients with metastatic castrate-resistant prostate cancer have been described,10 similar efforts are lacking in patients with mHSPC and nmCRPC. Such evaluations are crucial to identify practice variation and obstacles to receipt of guideline concordant care. To address this knowledge gap, we sought to describe contemporary prescribing trends among oncologists and urologists managing mHSPC and nmCRPC.

Figure 1. Duration of treatment among those patients with mHSPC treated with first-generation antiandrogens.
Figure 2. Comparative practice patterns for treatment of mHSPC between urologists (Uro) and oncologists (Onc) over time.

Using the IQVIA™ claims-based data set, which includes over 17 million cancer patients and 10,000 providers across all 50 United States, we identified men aged 18 years and older who received at least 1 systemic treatment for mHSPC or nmCRPC between 2015 and 2021. Patients with additional nonprostate malignancies were excluded. Treatments were divided into 4 groups: novel hormonal therapy (NHT: apalutamide, enzalutamide, darolutamide, abiraterone) with or without ADT, first-generation AAs (bicalutamide, nilutamide, flutamide), luteinizing hormone-releasing hormone monotherapy (ADT: degarelix, goserelin, histrelin, leuprolide, triptorelin, relugolix), and chemotherapy (cabazitaxel, docetaxel, estramustine, mitoxantrone). Prescribing patterns were assessed for the first 3 treatment lines by year of initiation.

Of the 77,738 patients receiving first-line treatment, 74,325 (95.6%) were mHSPC and 3,413 (4.4%) were nmCRPC. ADT monotherapy use in mHSPC decreased over time but remained the predominant management choice throughout the study period with 56% of patients receiving ADT monotherapy in 2015 and 48% in 2021. Urologists consistently managed mHSPC with ADT monotherapy in approximately 70% of cases, with little variation over time. In contrast, ADT monotherapy use steadily declined among oncologists from 55% in 2015 to 40% in 2021. Among those who received AAs, 35% continued treatment longer than 90 days and 8% continued these treatments for at least 1 year (Fig. 1). NHT use steadily increased from 20% of patients in 2018 to 29% of patients in 2021. Compared to oncologists, urologists were less likely to prescribe NHT for mHSPC at all time points and were slower to adopt NHT into practice (Fig. 2). Interestingly, similar trends were not observed in management of nmCRPC where urology and oncology practice patterns mirrored each other closely. Indeed, NHT use rose rapidly from 0% in 2017 to approximately 80% in 2021 regardless of prescriber type. The opposite was true for AA use, which showed a steady decline over the study period (Fig. 3). NHT comprised the majority of second- and third-line treatments, accounting for 40%-47% and 43%-96% of subsequent line treatments in mHSPC and nmCRPC, respectively.

Figure 3. Comparative practice patterns for treatment of nmCRPC between urologists (Uro) and oncologists (Onc) over time.

While limited by the inability to adjust for patient clinicopathological characteristics that may have influenced treatment choice, our findings suggest that NHT is underutilized in patients with mHSPC. Furthermore, many patients continue to receive non-guideline concordant care with long duration AAs or ADT monotherapy. Further work is needed to better understand these observed practice variations and identify actionable interventions to improve adoption of guideline-directed treatment, especially among urologists managing patients with advanced prostate cancer.

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