Case Report: A 91-Year-Old Patient With Non-Small Cell Lung Cancer Harboring MET Y1003S Point Mutation

The Y1003S point mutation in exon 14 of mesenchymal-epithelial transition (MET) is a rare mutation that can lead to oncogenic transformation. Few data are available on the characteristics of this mutation. This report presents an elderly patient with non-small cell lung cancer (NSCLC) and a Y1003S mutation in MET detected by next-generation sequencing (NGS).

In October 2020, a 91-year-old male was admitted to the Department of Respiratory and Critical Care Medicine, Ruijin Hospital because of an increased carcinoembryonic antigen. Imaging revealed highly suspicious lesions in the right upper lobe of the lung, right apex, and left upper lobe with traction of the adjacent pleura. The patient was histologically confirmed as having adenocarcinoma and the MET Y1003S mutation was detected by the NGS subsequently. After evaluation, the patient started crizotinib treatment in December 2020. In the first assessment of tumor response, a chest CT scan in January 2021 showed a partial response. The patient experienced a pulmonary embolism and an abnormal liver function during the treatment and recovered after symptomatic treatment. He maintained a partial response in the last available assessment in July 2021, with the right upper lung lesion being 26 × 9 mm.

The MET Y1003S mutation was detected in this case, and the patient achieved a partial response using crizotinib. This case highlighted the role of NGS in detecting a rare mutation. Successful remission of complications in such an elderly patient necessitates careful and timely management.