The treatment landscape of nonmetastatic castrate resistant prostate cancer: A contemporary perspective

Objectives: The incidence of nonmetastatic castrate resistant prostate cancer (nmCRPC) is not well defined in contemporary practice. The aim of this study is to describe the incidence and patterns of treatment of nmCRPC over the last 6 years at a single high-volume Australian health institution. Subjects and methods: All men newly diagnosed with prostate cancer at Western Health, Melbourne from January 2016 to December 2021 were included in the study. Those diagnosed with nonmetastatic prostate cancer and treated with medical or surgical castration for biochemical failure post attempted curative therapy were retrospectively reviewed for signs of castration resistance using prostate specific antigen (PSA) and testosterone biochemical markers up until October 2022. Results: From January 2016 to December 2021, 822 patients were diagnosed with prostate cancer, 590 had localized disease, 373 underwent definitive locoregional therapy, and 31 went on to have biochemical recurrence and were commenced on androgen deprivation therapy. Twenty-five patients had undetectable PSA levels and were classified as having nonmetastatic castrate sensitive prostate cancer (nmCSPC), whilst the remaining 6 patients experienced a rising PSA and were thus classified as nmCRPC. The incidence rate of nmCRPC was 228 cases per 100,000 person-years. The median age at the time of prostate biopsy was 74 years (interquartile range [IQR] 64 - 79) in the nmCRPC group and 62 years (IQR 57 - 69) in the nmCSPC group. The median prebiopsy PSA (ng/ml) in the nmCRPC and nmCSPC groups were 27.5 (IQR 19.9 - 50.4), and 16.5 (IQR 9.0 - 26.0), respectively. The median duration from prostate cancer diagnosis to onset of nmCRPC was 24 months (IQR 17 - 29) and the median PSA doubling time was 3.4 months (IQR 2.2 - 5.7). Conclusions: Thus, nmCRPC is an uncommon disease. Further population-based studies are required to better understand the incidence of nmCRPC. (c) 2024 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)