Effect of the number of negative lymph nodes removed on the survival and recurrence rate patients with non-small-cell lung cancer undergoing surgery: A multicenter retrospective cohort study

The role of the number of negative lymph nodes (NLNs) removed on survival and tumor recurrence after surgery in patients with non-small-cell lung cancer (NSCLC) is still unclear. This study aimed to evaluate the effect of the number of NLNs on overall survival (OS), recurrence-free survival (RFS), and recurrence rate of patients with NSCLC after surgery. This multicenter retrospective cohort study examined the medical profile of 1002 patients with a definite diagnosis of NSCLC who underwent surgery between 2021 and 2023 at one of our medical centers. Patients with NSCLC were classified into 4 groups based on the number of NLNs removed during surgery as follows. I: <10 (196 patients); II: 10 to 19 (341 patients); III: 20 to 30 (267 patients); and IV: >30 NLN (198 patients). The patients' demographics, tumor characteristics, and pathological findings were obtained by reviewing their medical records. The 5-year survival rate was 36.1%. The OS rate in groups I, II, III, and IV patients was 14%, 25%, 33%, and 43%, respectively (log-rank = 161.2, P = .001). Also, the RFS rate in patients of groups V/III was significantly higher than in groups I/II (P < .05). Multivariate analysis showed that the OS rate in group V and II patients was significantly higher than the other 2 groups (I and II). In addition, age > 65 years, comorbidity, tumor size > 3, advanced tumor stage, presence of metastasis, lymph node ratio > 0.3, total lobectomy, central tumor, and no adjuvant chemotherapy are significantly associated with decreased OS rate of patients with NSCLC. The increase in the number of NLNs removed during surgery was associated with an increase in the OS and RFS rates. Attention to this number can be a key factor in improving the survival prediction of patients with NSCLC.