Re-biopsy status among non-small cell lung cancer patients in Japan: A retrospective study

Disease progression because of acquired resistance is common in advanced or metastatic epidermal growth factor receptor (EGFR)-mutation positive non-small cell lung cancer (NSCLC), despite initial response to EGFR-tyrosine kinase inhibitors (TKIs). In Japan, transbronchial tissue biopsy is the most common sampling method used for re-biopsy to identify patients eligible for treatment. We aimed to investigate the success rate of re-biopsy and re-biopsy status of patients with advanced or metastatic NSCLC completing first-line EGFR-TKI therapy.This was a retrospective, multi-center, Japanese study. The target patients in the study were EGFR mutation-positive NSCLC patients. The primary endpoint was the success rate (number of cases in which tumor cells were detected/total number of re-biopsies performed×100). Secondary endpoints included differences between the status of the first biopsy and that of the re-biopsy in the same patient population, and the details of cases in which re-biopsy could not be carried out. Re-biopsy-associated complications were also assessed.Overall, 395 patients were evaluated (median age 63 years), with adenocarcinoma being the most common tumor type. Re-biopsy was successful in 314 patients (79.5%). Compared with the sampling method at first biopsy, at re-biopsy, the surgical resection rate increased from 1.8% to 7.8%, and percutaneous tissue biopsy increased from 7.6% to 29.1%, suggesting the difficulty of performing re-biopsy. Approximately half of the patients had T790M mutations, which involved a Del19 mutation in 55.6% of patients and an L858R mutation in 43.0%. Twenty-three patients (5.8%) had re-biopsy- associated complications, most commonly pneumothorax.Success rate for re-biopsy in this study was approximately 80%. Our study sheds light on the re-biopsy status after disease progression in patients with advanced or metastatic NSCLC. This information is important to improve the selection of patients who may benefit from third-generation TKIs.