Notable Response to Nivolumab During the Treatment of SMARCA4-Deficient Thoracic Sarcoma: A Case Report
Yuki Iijima, Rie Sakakibara, Masahiro Ishizuka, Takayuki Honda, Tsuyoshi Shirai, Tsukasa Okamoto, Tomoya Tateishi, Hiroyuki Sakashita, Meiyo Tamaoka, Akira Takemoto, Yuichi Kumaki, Sadakatsu Ikeda, Yasunari Miyazaki
Abstract
SMARCA4-deficient thoracic sarcoma is a rare tumor typically presenting as a mediastinal mass. The prognosis is estimated to be poor, and no effective treatment has been established. We present a case of a 76-year-old man who was diagnosed with SMARCA4-deficient thoracic sarcoma. The provisional diagnosis was carcinoma of unknown primary but subsequently corrected to SMARCA4-deficient thoracic sarcoma based on the panel-based cancer gene screening and immunohistochemistry. Cytotoxic chemotherapy as the first- and second-line did not reveal enough therapeutic effects but third-line therapy using nivolumab showed marked tumor regression, which was sustained. This is the first case report of SMARCA4-deficient thoracic sarcoma showing a good response to nivolumab. Immune checkpoint inhibitor might be therapeutic candidates for this type of tumor.