Retrospective database study of druggable mutation detection among patients with non-small cell lung cancer in Japan.

Generally, non-small cell lung cancer (NSCLC) accounts for 90% of lung cancer cases in Japan. The detection of druggable mutations is necessary for selecting the appropriate systemic therapy for patients with NSCLC. This study explored the proportion, characteristics, and treatments of patients with druggable mutations detected following standard therapy using cancer gene panel (CGP) testing. Adult NSCLC cases who had not been previously confirmed to have druggable mutations before CGP testing were extracted from the national database. A total of 1,425 cases were included and analyzed using descriptive statistics. Among the patients with NSCLC who underwent CGP testing, 44.6% exhibited druggable mutations (n = 635; mean age, 63.9 ± 10.7 years; 439 men [69.1%]). The most common types of mutations among those with druggable mutations were EGFR and NTRK, whereas the most common cancer subtypes were lung adenocarcinoma and lung squamous cell carcinoma. The median number of days from primary treatment initiation to druggable mutation detection was 701. As the first treatment after the CGP testing, 23.0% of the patients received molecularly targeted agents. Our findings emphasize the clinical importance of reducing barriers that hinder upfront multigene testing for driver gene mutations in ensuring patients receive appropriate treatment.