Erlotinib or Chemotherapy in Second-Line or Later Treatment of Tumor EGFR Wild-Type Pulmonary Adenocarcinoma Patients

Background: The intent of this study was to explore the treatment efficacy of erlotinib, pemetrexed or docetaxel in individual patients with tumor EGFR wild-type pulmonary adenocarcinoma who failed previous chemotherapy. Methods: We retrospectively reviewed the clinical data of our EGFR wild-type pulmonary adenocarcinoma patients who had disease progression after first-line chemotherapy and also had received erlotinib and pemetrexed or docetaxel treatment in our institution any time from July 2009 to June 2012. Results: Forty-one patients were identified and enrolled into the present study; all of them received erlotinib treatment. Thirty-five patients received additional pemetrexed treatment and 30 patients received additional docetaxel treatment, either preceding or following failure of erlotinib treatment. Erlotinib was used more frequently as a second-line treatment in 27 of 41 (65.9%) patients, followed by pemetrexed, which was used more frequently in the third-line setting for 21 of 35 (60%) patients. Docetaxel was typically used as the fourth-line treatment for 14 of 30 (46.7%) patients (all p < 0.01 when comparing different treatment agents). There was no difference in the tumor response rate between erlotinib (19.5%), pemetrexed (17.1%), and docetaxel (6.7%) (p = 0.301). For all patients, the median progression-free survival (PFS) was 10.9 weeks, 13.3 weeks, and 8.3 weeks when using erlotinib, pemetrexed, and docetaxel, respectively, as ≥ second-line treatment (p = 0.0261). No significant difference in PFS was found for individual agents when used in an earlier or later line of salvage therapy. Conclusions: This retrospective study of tumor EGFR wild-type pulmonary adenocarcinoma patients showed that erlotinib, pemetrexed, or docetaxel, individually, provided effective salvage therapy when patients had disease progression subsequent to first-line chemotherapy.