Different effects of crizotinib treatment in two non ‐small cell lung cancer patients with SDC4::ROS1 fusion variants

This study aimed to clarify the clinicopathological differences between twoSDC4::ROS1 positive NSCLC cases who had different responses to crizotinib. Cytology and pathology samples from two NSCLC cases withSDC4::ROS1 who were diagnosed and treated with crizotinib at Nihon University Itabashi Hospital were obtained. Case 1 has been well-controlled with crizotinib for over 5  years, but case 2 was worse and overall survival was 19 months. Sequencing analysis ofROS1 fusion genes was performed by reverse-transcription-PCR and Sanger's sequencing methods. In addition, thyroid transcription factor (TTF)-1, ROS-1, Ki67, and phosphorylated extracellular signal-regulated kinase (pERK)1/2 expression were investigated using immunohistochemistry. Sequencing analysis showedSDC4 exon2::ROS1 exon 32 (exon33 deleted) in case 1, and coexistence ofSDC4 exon2::ROS1 exon 34 andSDC4 exon2::ROS1 exon35 in case 2. The Ki67 index was not different, but ROS1 and pERK1/2 expression levels tended to be higher in the tumor cells of case 2 than in case 1. Therapeutic response to crizotinib and patients' prognosis inROS1 rearranged NSCLC may be related to the activation of ROS1 signaling, depending on ROS1 and pERK1/2 overexpression status, even if theROS1 fusion partner is the same.

Source: Thoracic Cancer - December 14, 2023 Category: Cancer & Oncology Authors: Yuta Ohishi, Yoko Nakanishi, Yukari Hirotani, Atsuko Suzuki, Tomoyuki Tanino, Haruna Nishimaki ‐Watanabe, Hiroko Kobayashi, Fumi Nozaki, Sumie Ohni, Xiaoyan Tang, Kentaro Hayashi, Yoshiko Nakagawa, Tetsuo Shimizu, Ichiro Tsujino, Noriaki T Tags: BRIEF REPORT Source Type: research