No abstract

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.

According to rapid development of chemotherapy in advanced non-small cell lung cancer (NSCLC), the Japan Lung Cancer Society has been updated its own guideline annually since 2010. In this latest version, all of the procedure was carried out in accordance with grading of recommendations assessment, development and evaluation (GRADE) system. It includes comprehensive literature search, systematic review, and determination of the recommendation by multidisciplinary expert panel which consisted of medical doctors, pharmacists, nurses, statisticians, and patients from patient advocacy group. Recently, we have had various types of chemotherapeutic drugs like kinase inhibitors or immune-checkpoint inhibitors. Thus, the guideline proposes to categorize patients into three entities: (1) driver oncogene-positive, (2) PD-L1 ≥ 50%, and (3) others. Based on this subgroup, 31 clinical questions were described. We believe that this attempt enables clinicians to choose appropriate treatment easier. Here, we report an English version of the Japan Lung Cancer Society Guidelines 2018 for NSCLC, stages IV.

Monitoring of cfDNA by dPCR is informative for prediction of afatinib efficacy, whereas that by NGS is reliable and has the potential to identify mechanisms of treatment resistance.

The T790M secondary mutation of the epidermal growth factor receptor (EGFR) gene accounts for 50% to 60% of cases of resistance to the first-generation EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib. The prevalence of T790M in EGFR mutation–positive patients who acquire resistance to the irreversible, second-generation EGFR-TKI afatinib has remained unclear, however. We here determined the frequency of T790M acquisition at diagnosis of progressive disease in patients with EGFR-mutated non–small cell lung cancer (NSCLC) treated with afatinib as first-line EGFR-TKI. Among 56 enrolled patients, 37 individuals underwent molecular analysis at rebiopsy. Of these 37 patients, 16 individuals (43.2%) had acquired T790M, including 11/21 patients (52.4%) with an exon 19 deletion of EGFR and 5/13 patients (38.5%) with L858R. None of three patients with an uncommon EGFR mutation harbored T790M. T790M was detected in 14/29 patients (48.3%) with a partial response to afatinib, 1/4 patients (25%) with stable disease, and 1/4 patients (25%) with progressive disease as the best response. Median progression-free survival after initiation of afatinib treatment was significantly (P = 0.043) longer in patients who acquired T790M (11.9 months; 95% confidence interval, 8.7–15.1) than in those who did not (4.5 months; 95% confidence interval, 2.0–7.0). Together, our results show that EGFR-mutated NSCLC patients treated with afatinib as first-line EGFR-TKI acquire T790M at the time of progression at a frequency similar to that for patients treated with gefitinib or erlotinib. They further underline the importance of rebiopsy for detection of T790M in afatinib-treated patients.