Good response to pemetrexed in patients of lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutations

There are no reports about epidermal growth factor receptor (EGFR) mutations and the responsiveness to pemetrexed treatment. In order to understand the influence of EGFR mutations on pemetrexed response, we performed EGFR sequencing of lung adenocarcinoma from patients undergoing pemetrexed treatment and analyzed their response to pemetrexed. The pemetrexed-treated lung adenocarcinoma patients with adequate specimens for EGFR sequencing and measurable target lesions were enrolled for response analysis. Demographic data, EGFR mutation status, response to pemetrexed, and survival data were collected. From January 2004 to December 2008, 156 patients with measurable target lesions and EGFR sequencing results had complete clinical data for analysis. The patients with EGFR mutations (N = 93) had a better response rate (p = 0.016) and longer progression-free survival (PFS) (p = 0.030) than those with wild type EGFR (N = 63). By multivariate analysis, those who had better performance status (p = 0.013) and EGFR mutations (p = 0.021) had a longer PFS. In conclusion, lung adenocarcinoma patients receiving pemetrexed with EGFR mutations have a better response rate and longer PFS than those with wild type EGFR.