Evaluation of erlotinib for the treatment of patients with non-small cell lung cancer with epidermal growth factor receptor wild type.

Erlotinib is one of the treatment choices for patients with advanced non-small cell lung cancer (NSCLC), regardless of the epidermal growth factor receptor (EGFR) mutation status. However, its efficacy for the treatment of patients with NSCLC with EGFR wild type or who are beyond the usage of gefitinib remains controversial. The present study therefore retrospectively assessed the efficacy of erlotinib in patients with wild type EGFR who had previously undergone gefitinib therapy. A total of 222 patients with NSCLC who received chemotherapeutic treatment with erlotinib between July 2007 and February 2013 were evaluated. The background variables, response rates, progression-free survival (PFS) and overall survival rates were retrospectively analyzed. The male/female ratio of patients was 103/119, and patients had a median age of 63 years (range, 33-95 years). A total of 10 of the 222 patients had clinical stages IIIB/IV, 191 had adenocarcinoma, 5 had large cell carcinoma, 10 had squamous cell carcinoma and 6 had NSCLC of a variety not otherwise specified. The EGFR mutation was positive, wild type or unknown in 95, 52 and 75 patients, respectively. In the 52 patients with EGFR wild type, there were 3 partial responders, 25 with stable disease and 24 with progressive disease, for a response rate of 6% [95% confidence interval (CI), 1.3-15%]. The median PFS of EGFR wild type and positive were 1.1 months (95% CI, 1.04-1.16 months) and 5.42 months (95% CI, 5.43-5.68 months), respectively. The results of the study demonstrated that erlotinib is not sufficiently effective for patients with NSCLC who possess the EGFR wild type status.