Impact of lymph node dissection on overall survival and cancer-specific survival in elderly patients with early-stage non-small cell lung cancer: a SEER database analysis

<b>Aim:</b> The aim of the study is to understand the impact of lymph node dissection (LND) on overall survival (OS) and cancer-specific survival (CSS) in elderly patients with early-stage non-small cell lung cancer (NSCLC), and to find the best characteristics of the beneficiary population. <b>Materials & methods:</b> Based on the Surveillance, Epidemiology, and End Results (SEER) database, the effect of LND on OS and CSS in elderly patients with early-stage NSCLC was analyzed using a retrospective method. Multivariate Cox regression model was employed to determine the factors influencing OS and CSS in elderly patients with early-stage NSCLC. Kaplan-Meier and sequential landmark analyses were conducted to estimate and compare the survival curves and median follow-up time of patients. <b>Results:</b> The study included 27,540 participants. The age distribution of patients who underwent LND was mostly 65-74 years old (61.8%). 83.2% received chemotherapy concurrently, and 9.0% received radiotherapy. A total of 10,240 patients were successfully matched after propensity score matching. Elderly patients with early-stage NSCLC who received LND (OS_median: 60 vs 23; CSS_median: 136 vs 32) had significantly improved OS and CSS, with consistent results from sequential landmark analysis of long-term survivors. The results of subgroup analyses displayed that factors such as gender, age, marital status, grade and tumor size affected the prognosis of elderly patients with early-stage NSCLC who received LND. <b>Conclusion:</b> The OS and CSS in patients with early-stage elderly NSCLC who underwent LND at different time points after diagnosis were significantly improved.