Clinical outcomes of EGFR-TKIs in advanced squamous cell lung cancer

Jin-Fei Si, Jing Xiang, Jing-Wen Wei, Yue Hao,  Zheng-Bo Song

Abstract:

We aimed to explore the treatment efficacy of first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) for lung squamous cell carcinoma (SCC) patients and identify potential beneficial subgroups of EGFR-mutated lung SCC patients in this study. Between February 1st, 2013 and December 1st, 2021, 657 advanced lung SCC patients were enrolled at Zhejiang Cancer Hospital. Amplification refractory mutation system PCR or next-generation sequencing were used to detect gene abnormality. Clinicopathological features were analyzed by chi-square test and the clinical results of lung SCC patients who received first-generation EGFR-TKI were analyzed by the Kaplan-Meier method. Lung SCC patients harboring EGFR mutation accounted for 11.0% in this study. Of 657 lung SCC patients, the median PFS and OS of 116 patients who received targeted therapy were 3.6 months and 16.2 months, patients treated with targeted therapy had similar OS to patients without targeted therapy (p=0.839). Of 110 lung SCC patients who received first-generation EGFR-TKI, EGFR-mutated patients had long PFS (p=0.000) but similar OS (p=0.472) than patients with EGFR wide type. EGFR-mutated SCC patients who received first-generation EGFR-TKI as a first-line benefit are equal to patients who received first-generation EGFR-TKI as the second line or beyond according to similar PFS (p=0.311) and OS (p=0.721) between them. In addition, there was also no significant difference in PFS (p=0.376) and OS (p=0.205) between patients with exon 19 deletion and L858R point mutation. Lung SCC patients harboring EGFR mutation received first-generation EGFR-TKI had better clinical survival than patients with EGFR wide type.