Real-world clinical analysis in 190 advanced NSCLC patients with uncommon EGFR mutations: A multi-center study.

Different from EGFR 19Del and L858R mutations, the panoramic description of uncommon EGFR mutations is far from mature. Our understanding of its population characteristics, treatment response and drug resistance mechanisms is urgent to be expanded and deepened. Our study enrolled 437 NSCLC patients with uncommon EGFR mutations from four clinical centers. The clinical characteristics of all patients and the treatment outcomes of 190 advanced patients that received pharmacotherapy were analyzed. Moreover, the acquired resistance mechanisms were explored based on 53 times of tissue or liquid re-biopsy data in 45 patients. Patients with EGFR 20ins had shorter survival time compared with non-20ins mutations. A total of 149 cases had ever received EGFR-TKI, and afatinib was significantly superior to other EGFR-TKIs both in ORR and mPFS in all uncommon mutations and especially in L861Q group. The most common acquired drug resistance mechanism was MET amplification, and followed by EGFR T790M, which is significantly different from common EGFR mutations.