Sharon Pei Yi Chan1,11, Chen Ee Low2,11, Chun En Yau2,11, Tzu Ping Lin3,11, Weining Wang4, Sam Xin Xiu5, Po Yin Tang5, Baiwen Luo6, Nur Fazlin Bte Mohamed Noor4, Kristen Alexa Lee7, Jianbang Chiang4, Tan Boon Toh6,8, Edward Kai-Hua Chow1,6,8,9 and Valerie Shiwen Yang3,4,10 1Cancer Science Institute of Singapore, National University of Singapore, Singapore; 2Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 3Translational Precision Oncology Laboratory, Institute of Molecular and Cell Biology, A*STAR, Singapore; 4Division of Medical Oncology, National Cancer Centre Singapore, Singapore; 5Department of Anatomical Pathology, Singapore General Hospital, Singapore; 6The N1 Institute for Health, National University of Singapore, Singapore; 7Department of Vascular and Interventional Radiology, Singapore General Hospital, Singapore; 8The Institute for Digital Medicine (WisDM), Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 9NUS Centre for Cancer Research (N2CR), Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 10SingHealth Duke-NUS Oncology Academic Clinical Program, Duke-NUS Medical School, Singapore Corresponding author: yangswvimcb.a-star.edu.sg

↵11 These authors contributed equally to this work.

Abstract

Metastatic porocarcinomas (PCs) are vanishingly rare, highly aggressive skin adnexal tumors with mortality rates exceeding 70%. Their rarity has precluded the understanding of their disease pathogenesis, let alone the conduct of clinical trials to evaluate treatment strategies. There are no effective agents for unresectable PCs. Here, we successfully demonstrate how functional precision medicine was implemented in the clinic for a metastatic PC with no known systemic treatment options. Comprehensive genomic profiling of the tumor specimen did not yield any actionable genomic aberrations. However, ex vivo drug testing predicted pazopanib efficacy, and indeed, administration of pazopanib elicited remarkable clinicoradiological response. Pazopanib and its class of drugs should be evaluated for efficacy in other cases of PC, and the rationale for efficacy should be determined when PC tumor models become available. A functional precision medicine approach could be useful to derive effective treatment options for rare cancers.

Received July 14, 2023. Accepted October 31, 2023.