Case Report: Significant Efficacy of Pyrotinib in the Treatment of Extensive Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer Cutaneous Metastases: A Report of Five Cases.

Abstract

BACKGROUND:

Breast cancer (BC) is the most common tumor to develop cutaneous metastases. Most BCs with cutaneous metastasis are human epidermal growth factor receptor 2 (HER2)-positive subtypes. Although the molecular mechanisms of breast cancer metastasis to different sites and the corresponding treatment methods are areas of in-depth research, there are few studies on cutaneous metastasis.

CASE PRESENTATION:

Five HER2-positive BC patients with extensive cutaneous metastases were treated with a regimen containing pyrotinib, a novel small-molecule tyrosine kinase inhibitor that irreversibly blocks epidermal growth factor receptor (EGFR), HER2, and human epidermal growth factor receptor 4 (HER4), then their cutaneous metastases quickly resolved at an astonishing speed and their condition was well controlled during the follow-up period.

CONCLUSIONS:

This case series reports the significant therapeutic effect of pyrotinib on cutaneous metastases of HER2-positive BC for the first time. Based on this, we recommend that pyrotinib can be used as a supplement to trastuzumab for HER2-positive BC patients with cutaneous metastases. In addition, we should consider that the pan-inhibitory effect of pyrotinib on EGFR, HER2, and HER4 may provide a dual therapeutic effect against HER2 and mucin 1.

• Authors: Nan Wang, Lin Li, Youyi Xiong, Jiangrui Chi, Xinwei Liu, Chaochao Zhong, Fang Wang, Yuanting Gu
• Journal: Frontiers in oncology (Front Oncol) Vol. 11 Pg. 729212 ( 2021) ISSN: 2234-943X [Print] Switzerland
• PMID: 34976791 (Publication Type: Case Reports)
• Copyright: Copyright © 2021 Wang, Li, Xiong, Chi, Liu, Zhong, Wang and Gu.