Duration of prior gefitinib treatment predicts survival potential in patients with lung adenocarcinoma receiving subsequent erlotinib

PurposeWe investigated survival potential in patients receiving erlotinib after failure of gefitinib, focusing on response and time to progression (TTP) with gefitinib.MethodsWe retrospectively reviewed lung adenocarcinoma patients who received erlotinib after experiencing progression with gefitinib. Our primary objective was to evaluate the prognostic significance of erlotinib therapy.ResultsA total 42 lung adenocarcinoma patients were included in this study. Overall disease control rate was 59.5% (partial response [PR], 2.4%; stable disease [SD], 57.1%). Median overall survival was 7.1 months, and median progression-free survival was 3.4 months. The number of patients who achieved PR and non-PR (SD+ progressive disease [PD]) with gefitinib were 22 (52%) and 20 (48%), respectively. Patients with PR for gefitinib showed significantly longer survival times than those with non-PR (9.2 vs. 4.7 months; p = 0.014). In particular, among PR patients, those with TTP <12 months on gefitinib showed significantly longer survival times than those with TTP ≥12 months (10.3 vs. 6.4 months; p = 0.04).ConclusionsErlotinib may exert survival benefit for lung adenocarcinoma patients with less than 12 months of TTP of prior gefitinib who achieved PR for gefitinib.