160P - Real world study of lung squamous cell carcinoma patients with EGFR mutation treated with EGFR-TKI

Advanced NSCLC

160P - Real world study of lung squamous cell carcinoma patients with EGFR mutation treated with EGFR-TKI

Authors

Liyun Miao (CN)
Gen Lin (CN)
Yifen Wu (CN)
Jianhua Chen (CN)
Xinghao Ai (CN)
Mingming Yuan (CN)
Rongrong Chen (CN)

Presenter

Liyun Miao (CN)

Abstract

Abstract

Background

EGFR tyrosine kinase inhibitors (TKIs) have greatly improved the outcomes of EGFR mutation-positive adenocarcinomas of the lung; however, the role of genetic testing and efficacy of EGFR-TKI in lung squamous cell carcinoma (SCC) remains controversial.

Methods

A total of 265 patients with advanced SCC who underwent genetic testing at our institute from 2016 to 2017 were included for analysis. Mutation profiling was performed with targeted capture based next-generation sequencing, which enables simultaneously assess single-nucleotide variants, insertions/deletions, rearrangements, and somatic copy-number alterations across 59 genes. Response assessment was done using Response Evaluation Criteria In Solid Tumors (RECIST) 1.1. Kaplan–Meier method was used for calculating time to progression (TTP).

Results

EGFR mutation was detected in 28 out of 265 patients with SCC (10.6%). Of the patients, 12 was with EGFR exon 21 L858R mutation, 10 was exon 19 E746_A750del mutation and 2 was exon 21 L861Q mutation. In addition, 8 was exon 20 mutations with 2 T790M mutation, 2 S768I mutation and 1 P772_H773insR, S768_D770dup, V774M, N771dup mutation resprectively. For the 2 patients with de novo T790M mutation, one has concurrent L858R mutation and the other EGFR N771dup. Furthermore, 10 out of the 27 patients received TKIs during their treatment. Five patients were treated with chemotherapy as first line, and five were EGFR-TKI as the first line. The median TTP on EGFR TKI was 10.5 months. There was no significant difference of TTP between the two groups treated with EGFR-TKI as first line or not (16 months vs 7 months, p = 0.19).

Conclusions

EGFR mutations are present in over 10% SCC patients. These patients predict a better outcome if given TKI, but it may be inferior to the outcomes of EGFR-positive adenocarcinomas treated with TKI.