Abstract
BACKGROUND: It has been proven that the status of epidermal growth factor receptor (EGFR) gene mutation was related to effects of gefitinib in patients with advanced non-small cell lung cancer (NSCLC). The aim of this study is to reports distribution of EGFR gene mutations in advanced NSCLC and their influence on effect of gefitinib. METHODS: From Jan 2007 to Dec 2009, 160 patients with advanced non-squamous NSCLC received EGFR mutation tests, and EGFR exon 19 and 21 were amplified by mutant-enriched PCR and analyzed by sequencing. Among those patients, 111 received gefitinib therapy. Overall survival (OS) and progression free survival (PFS) were calculated using the Kaplan-Meier method and a Cox regression analysis was used to detect differences between strata. RESULTS: The percentage of EGFR mutation in advanced non-squamous NSCLC was 55%, and it was only significantly related with pathological type. OS of the patients with or without EGFR gene mutations were 29.0 months (95%CI: 24.2-33.8) and 21.0 months (95% CI: 14.7-27.3) respectively, and the difference was not significant. PFS of patients with or without EGFR gene mutations were 17.0 months (95% CI: 5.6-17.6) and 11.6 months (95% CI 8.6-25.4), and the difference was significant (P = 0.022). Multivariate analysis shows that OS was significantly related with ECOG status, pathological type and EGFR mutation statuses, and PFS was significantly related to ECOG status, former regimens number and EGFR mutation statuses. There were no significant differences in OS and PFS between patients with EGFR exon 19 deletions and those with exon 21 point mutation. CONCLUSIONS: PFS of patients with EGFR mutations was better than those without EGFR mutations, but OS was similar. There were no significant differences in OS and PFS between patients with EGFR exon 19 deletions and those with exon 21 point mutation.