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.

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. 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. 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: 60 vs 23; CSS: 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. The OS and CSS in patients with early-stage elderly NSCLC who underwent LND at different time points after diagnosis were significantly improved.