Real-World Evidence of Diagnostic Testing for Driver Oncogene Mutations in Lung Cancer in Japan

INTRODUCTION: Diagnostic testing is important in determining appropriate treatment for individuals with lung cancer. In 2018, testing of five biomarkers (EGFR, ALK, ROS1, BRAF, programmed cell death-ligand 1 [PD-L1]) was approved in Japan. Information is lacking regarding real-world testing patterns. METHODS: This descriptive, retrospective observational study used the Japan Medical Data Vision Co., Ltd. (MDV), database (June 2017–November 2018) and covered data for EGFR, ALK, ROS1, and PD-L1; records on BRAF testing were not yet available. Adults diagnosed with having lung cancer (International Classification of Diseases-10 C34) with record of any biomarker test ordered were included. RESULTS: Of 8323 patients with any biomarker test, 83.2% were tested for EGFR, 55.3% for ALK, 32.2% ROS1, and 77.2% PD-L1. Combinations of EGFR with other biomarkers accounted for approximately 80% of the testing patterns; 1427 patients (17.1%) had combination testing ordered for EGFR/ALK/ROS1/PD-L1, but some biomarker combinations were tested in less than 1% of the cases. Median time from first testing order to treatment order was 22 (range: 2–525) days overall and increased with number of testing instances: 21 (2–509) days for patients with one, 28 (3–525) days for patients with two, and 30 (9–502) days for patients with three. A 7-day pattern of peaks was observed in the test order date and time to treatment. CONCLUSIONS: This real-world evidence revealed variations in diagnostic testing patterns, which could affect time to treatment in Japan. Variations are likely influenced by individual biomarker prioritization considering limited tissue samples in clinical practice.