Efficacy and toxicity of pemetrexed monotherapy for previously untreated elderly patients with non-squamous cell lung cancer with wild-type (or Unknown) EGFR status

Background: The efficacy of docetaxel, vinorelbine, or gemcitabine monotherapy in previously untreated elderly patients with non-small cell lung cancer has been reported. Pemetrexed monotherapy has shown clinically equivalent efficacy to docetaxel, a standard therapeutic option, in patients with previously treated non-small cell lung cancer and in those with a lower incidence of toxicity such as febrile neutropenia. Objective: In the present study, we aimed to investigate the efficacy and toxicity of pemetrexed in previously untreated elderly patients with non-squamous cell lung cancer and compare the results with those of docetaxel, considered a standard chemotherapeutic agent. Methods: We retrospectively reviewed the medical records of patients with non-squamous cell lung cancer with wild-type (or unknown) epidermal growth factor receptor status who received pemetrexed or docetaxel monotherapy as first-line chemotherapy. Results: We analyzed 6 patients with lung adenocarcinoma in the pemetrexed group and 6 patients with lung adenocarcinoma in the docetaxel group. The median progression-free survival was 3.6 months for patients receiving pemetrexed and 3.1 months for those receiving docetaxel (p=0.45). The median overall survival was 14.8 months in the pemetrexed group and 10.9 months in the docetaxel group (p=0.36). Patients who received docetaxel were more likely to have grade 3 or 4 neutropenia and febrile neutropenia than those receiving pemetrexed. However, 2 patients who received pemetrexed showed grade 3 pneumonitis. Conclusion: Pemetrexed monotherapy is a promising treatment for previously untreated elderly patients with non-squamous cell lung cancer.