99P - Efficacy of gefitinib in advanced squamous cell lung cancer harboring epidermal growth factor receptor mutations: A pooled analysis of individual patient data

Abstract

Background: Gefitinib has demonstrated clinical benefits for patients suffering from lung adenocarcinoma with activating mutation of epidermal growth factor receptor (EGFR). However, the efficacy of gefitinib for advanced squamous cell lung cancer (SqCLC) harboring EGFR mutation is still unclear. Methods: We conducted a pooled analysis of individual patient data based on the published reports that included patients with advanced SqCLC harboring EGFR mutation who were treated with gefitinib. The patients selected for the analysis were advanced SqCLC patients harboring EGFR mutations who were treated with gefitinib and described in reports containing the data of the histology, EGFR mutation status and type, response to gefitinib, and outcome of these patients. Results: Tweenty-six patients were selected from ten reports for the pooled analysis. One patient obtained a complete response (CR) and five patients obtained a partial response (PR); the response rate (RR) was 23.1%. The median progression-free survival (mPFS) and overall survival (mOS) was 3.1 months and 10.8 months, respectively. The RR and PFS were significantly inferior in the SqCLC patients harboring EGFR mutations to non-SqCLC patients harboring EGFR mutations selected from the same published reports (RR: 23.1% vs. 62.2%, P < 0.001; PFS: 3.1 vs. 9.2 months, P < 0.001, respectively). While no significant difference in OS was observed between the two groups (OS: 10.8 vs. 17.7 months, P = 0.082). Conclusions: The efficacy of gefitinib was inferior in advanced SqCLC harboring EGFR mutation as compared to non-SqCLC harboring EGFR mutation. The underlining mechanisms of resistance to EGFR-TKI in SqCLC with EGFR mutation should be deeply explored in the further studies. Legal entity responsible for the study: Chongqing Cancer Hospital & Cancer Institute Funding: Chongqing Cancer Hospital & Cancer Institute Disclosure: All authors have declared no conflicts of interest.