Impact of examined lymph node count on survival outcomes in patients with stage T1-2N0M0 small cell lung cancer undergoing surgery: A retrospective cohort study

Abstract

To explore the relationship between the count of examined lymph nodes (ELNs) and survival outcomes in patients with stage T1-2N0M0 small cell lung cancer (SCLC) after surgical treatment. We analyzed data from patients with SCLC in the Surveillance, Epidemiology, and End Results database. The study focused on examining the correlation between the ELN count and both cancer-specific survival (CSS) and overall survival (OS). This relationship was investigated using restricted cubic spline curves within the framework of multivariable Cox regression models. The cutoff value for both CSS and OS was 7 ELN counts. Patients with ELN < 7 had a median CSS of 64 months, significantly lower than 123 months of patients with ELN ≥ 7 (P = .012). Multivariable Cox regression analysis indicated that ELN ≥ 7 was an independent prognostic factor for CSS (hazard ratio = 0.50, 95% confidence interval: 0.30–0.83; P = .007). Similarly, Patients with ELN < 7 had a median OS of 41 months for patients with ELN < 7, compared to 103 months for those with ELN ≥ 7 (P = .004). Multivariable Cox regression analysis confirmed that ELN ≥ 7 was an independent prognostic factor for OS (hazard ratio = 0.54, 95% confidence interval: 0.36–0.81; P = .003). ELN ≥ 7 is recommended as the threshold for evaluating the quality of postoperative lymph node examination and for prognostic stratification in patients with stage T1-2N0M0 SCLC undergoing surgery.