Analysis of the effect of chemotherapy on overall survival of elderly patients with non-small cell lung cancer based on the propensity score matching approach

We conducted a retrospective analysis of elderly stage I-III non-small cell lung cancer (NSCLC) in the hope of providing more evidence for adjuvant chemotherapy in elderly NSCLC patients. Data from NSCLC patients ≥ 70 years of age during 2010-2015 from the Surveillance, Epidemiology, and End Results database were used to analyze the data. Patients were divided into chemotherapy and non-chemotherapy groups. Propensity score matching was performed to construct a balanced cohort of chemotherapy and non-chemotherapy. Data from the matched 2 groups were subjected to Kaplan-Meier analysis, and multivariate COX regression analysis was performed to evaluate the effect of chemotherapy on overall survival. Subgroup analyses were performed to determine the specific benefit population. A total of 18,126 eligible patients were enrolled in the study. Among these, 4776 patients (26.35%) received chemotherapy, while 13,350 patients (73.65%) did not. Utilizing propensity score matching, 6974 patients were successfully matched, achieving baseline equilibrium between the chemotherapy and non-chemotherapy groups. In the matched dataset, multivariate Cox regression analysis indicated a 26% reduction in the risk of mortality for the chemotherapy group compared to the non-chemotherapy group (hazard ratio = 0.74, 95% confidence interval = 0.70-0.78, P < .001). Furthermore, Kaplan-Meier analysis of the matched data demonstrated a survival advantage for the chemotherapy group relative to the non-chemotherapy group, with a statistically significant difference observed. Additionally, subgroup analyses revealed that specific demographics, including Black patients, those with higher grades of tumor differentiation, and patients classified as stage II-III, T2-T3, and N1-N2, were more likely to benefit from chemotherapy. Through the findings of this study, it was demonstrated that chemotherapy can enhance the prognosis of elderly patients with NSCLC. This is particularly evident in patients who are Black, possess a high tumor cell grade classification, are in advanced stages of the disease, and exhibit multiple peripheral lymph node metastases, as they are likely to derive significant benefits from this treatment.