Prognostic factors in older patients with wild-type epidermal growth factor receptor advanced non-small cell lung cancer: a multicenter retrospective study

Background: Over 40% Japanese patients with lung cancer are above 75 years of age. A specific strategy to treat such older patients is necessary because most trials exclude older patients with poor physical health. Herein, we aimed to identify predictive factors associated with overall survival (OS) in older patients by evaluating patient backgrounds and laboratory data before the start of treatment. Methods: This multicenter retrospective medical chart review study was conducted at three Japanese institutions and involved patients aged 75 years and above with epidermal growth factor receptor (EGFR) mutation-negative advanced non-small cell lung cancer (NSCLC). Of the patients, 75 had received best supportive care (BSC) and 49 mono-chemotherapy or platinum-doublet chemotherapy, including immune checkpoint inhibitors (ICIs). OS after diagnosis was analyzed using the Kaplan-Meier survival analysis. Cox proportional hazard models, which included age, Eastern Cooperative Oncology Group performance status (ECOG PS), staging, serum albumin levels, and receipt of chemotherapy were analyzed. Results: Age at diagnosis was not shown to be related to OS in patients receiving BSC. In patients aged 81 years and above, the chemotherapy group tended to have longer survival than did the BSC group, but there was no statistically significant difference in the median OS between the two groups due to the very small number of subjects (n: 30 vs. 12, median: 52 vs. 30 weeks, hazard ratio: 0.512, 95% confidence interval: 0.232-1.130, P=0.088). The patients' performance status and albumin levels at lung cancer diagnosis had the highest impact on OS in the BSC group. Conclusions: Careful consideration should be given to the indications of chemotherapy for patients aged 81 years and above with wild-type EGFR advanced non-small lung cancer.