Androgen receptor splice variant 7 (ARV-7) is a resistance mechanism to hormonal therapy in metastatic castrate-resistant prostate cancer (mCRPC). It has been associated with poor outcomes. On progression to castrate resistance, ARV-7 positivity has been identified in global populations at an incidence of 17. 8%-28.8%. Here, we characterize the incidence of ARV-7 positivity in Asian patients with mCRPC in a prospective fashion and evaluate its implications on treatment outcomes.
Patients with mCRPC from multiple centers in Southeast and East Asia were enrolled in a prospective manner before initiation of androgen receptor signaling inhibitors or docetaxel. ARV-7 status was evaluated at baseline with three commercially available assays: AdnaTest Prostate Cancer platform, Clearbridge method, and IBN method. Clinical outcomes at progression were assessed. The primary end point of this study was prevalence of ARV-7 positivity; secondary end points were incidence of ARV-7 positivity, prostate specific antigen (PSA) response rate, PSA progression-free survival (PFS), and overall survival (OS).
A total of 102 patients with a median age of 72 years at enrollment participated. Overall, an incidence of ARV-7 positivity of between 14.3% and 33.7% in Asian patients with mCRPC was demonstrated depending on the assay used. Patients found to have ARV-7 positivity at enrollment had a numerically worse PSA PFS compared with ARV-7 negative patients.
In this study, the incidence of ARV-7 positivity in Asian patients with mCRPC was shown to be similar to the global population. Patients with ARV-7 positivity appear to have more aggressive disease with numerically worse PSA PFS and OS. Further prospective studies are needed to fully characterize the relationship that ARV-7 positivity has on prognosis of Asian patients with mCRPC.
JCO precision oncology. 2024 Jun [Epub]
Daniel Ang, Johan Chan, Whee Sze Ong, Hui Shan Tan, Quan Sing Ng, John Yuen, Kenneth Chen, Kae Jack Tay, Siew Wei Wong, Marniza Saad, Masayoshi Nagata, Shigeo Horie, Phichai Chansriwong, Chi-Fai Ng, Alvin Wong, Melvin L K Chua, Chee Keong Toh, Min-Han Tan, Tony Lim, Ali Asgar S Bhagat, Ravindran Kanesvaran
Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore., Clinical Trials and Epidemiological Sciences, National Cancer Centre Singapore, Singapore, Singapore., Division of Surgery and Surgical Oncology, Department of Urology, National Cancer Centre Singapore, Singapore, Singapore., Parkway Cancer Centre, Singapore, Singapore., Department of Clinical Oncology, University of Malaya, Kuala Lumpur, Malaysia., Department of Urology, Juntendo University, Tokyo, Japan., Ramathibodi Hospital, Bangkok, Thailand., Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong, China., Department of Haematology-Oncology, National University Cancer Institute, Singapore, Singapore., SingHealth Duke-NUS Oncology ACP, Singapore, Singapore., Curie Oncology, Singapore, Singapore., Lucence Diagnostics Pte Ltd, Singapore, Singapore., Division of Pathology, Department of Anatomical Pathology, Singapore General Hospital, Singapore, Singapore., Biolidics Limited, Singapore, Singapore.