Prevalence of MET exon 14 skipping mutation in pulmonary sarcomatoid carcinoma patients without common targetable mutations: A single-institute study

Background: Pulmonary sarcomatoid carcinoma (PSC) is a rare histologic subtype of nonsmall cell lung cancer with limited targeted treatment options. In this study, we aimed to investigate the prevalence of MET ex14 skipping mutation in PSC patients without common targetable mutations in EGFR, KRAS, ALK, ROS1, and RET. Materials and Methods: In total, 46 resected specimens of PSC without these mutations were assessed for MET ex14 skipping mutation by next-generation sequencing (NGS) based on the Oncomine Focus Assay libraries. Results: Among 52 cancer-relevant genes included in the targeted NGS panel, the MET ex14 skipping mutation was the only mutation identified in our cohort, which was present in 4 (9%) of 46 patients. For patients with METex14 skipping mutation, the median overall survival (OS) was 35 months (1050 days) compared with a median OS of 27 months (807 days) for those without METex14 skipping mutation (hazard ratio [HR] = 0.59, P = 0.488). The median disease-free survival (DFS) in METex14 skipping mutation-positive patients was 18 months (540 days) compared with a median DFS of 13.6 months (408 days) for negative patients (HR = 0.76, P = 0.680). Conclusions: These findings reflect the prevalence of MET ex14 skipping mutation as up to 9% in Chinese patients with PSC negative for other common targetable mutations, allowing provision of appropriate genetic counseling and treatment in these patients. A larger population-based study is warranted to determine the clinicopathological and prognostic implications of MET ex14 skipping mutation in PSC