Efficacy of gefitinib for non-adenocarcinoma non-small-cell lung cancer patients harboring epidermal growth factor receptor mutations: a pooled analysis of published reports

The efficacy of gefitinib for patients with non-adenocarcinoma non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations is unclear, because only a small percentage of patients enrolled in the clinical trials to evaluate the efficacy of gefitinib for tumors harboring EGFR mutation were non-adenocarcinoma NSCLC. A pooled analysis was conducted to clarify the efficacy of gefitinib for non-adenocarcinoma NSCLC patients harboring EGFR mutations. A systematic search of the PUBMED databases was conducted to identify all clinical reports that contained advanced non-adenocarcinoma NSCLC patients harboring EGFR mutations and treated with gefitinib. The selected patients were advanced non-adenocarcinoma NSCLC patients harboring EGFR mutations who were treated with gefitinib and described in reports containing the data of the histology, status of EGFR mutations and response to gefitinib. This study selected 33 patients from 15 reports. Twenty-seven and three of the 33 patients were squamous cell carcinoma and adenosquamous cell carcinoma, respectively. One patient each had large-cell carcinoma, pleomorphic carcinoma and spindle cell carcinoma. Twenty-one patients (64%) had sensitive EGFR mutations. The response rate (RR), disease control rate (DCR) and median progression-free survival (mPFS) was 27%, 67-70% and 3.0 months, respectively. These factors were statistically significantly inferior in the non-adenocarcinoma NSCLC patients harboring EGFR mutations to adenocarcinoma patients harboring EGFR mutations selected from the same published reports (RR: 27%vs 66%, P = 0.000028; DCR: 67-70%vs 92-93%, P = 0.000014; mPFS: 3.0 vs 9.4 months, P = 0.0001, respectively). Gefitinib is less effective in non-adenocarcinoma NSCLC harboring EGFR mutations than adenocarcinoma harboring EGFR mutations.