Clinical study on the effects of neoadjuvant chemotherapy on lymph node ratio, prognosis, and survival analysis of stage ⅢA-N2 non-small cell lung cancer

Abstract

Objective: To investigate the effect of neoadjuvant chemotherapy (NCT) on the lymph node ratio (LNR) of patients with stage ⅢA-N2 non-small cell lung cancer (NSCLC), and analyze the relationship between LNR and prognosis. Methods: The data of 128 patients with stage ⅢA-N2 NSCLC admitted to the Department of Cardiothoracic Surgery of the First Affiliated Hospital of Hebei North University from January 2013 to December 2018 were retrospectively collected. The patients were divided into two groups according to the treatment method. The patients in the observation group (64 cases) were treated with NCT and surgery, and the patients in the control group (64 cases) were treated with surgery. Lymph node metastasis and survival were observed in the two groups. Subgroups were divided according to LNR and N2 lymph node status, and survival analysis was performed for each subgroup. Univariate and multivariate analysis were conducted for the observation group. Results: The number of metastatic lymph nodes, the proportion of patients with positive lymph nodes, and the rate of lymph node metastasis in the observation group were lower than those in the control group,3.8±2.1 vs 4.9±2.4,92.2% vs 100%,19.1% vs 22.4% respectively (all P<0.05). Progression-free survival (PFS) and overall survival (OS) in the observation group were better than those in the control group (both P<0.05). Both the observation and control subgroups with low LNR had better PFS and OS than the subgroups with high LNR (both P<0.05). Patients in the observation group with non-multi-site N2 lymph node metastasis had better PFS and OS (both P<0.05). Univariate analysis of observation group showed that patients with low LNR had better 2-year PFS and OS(both P<0.05). Multivariate analysis showed that the higher the LNR, the greater the risk of death (HR=2.178,95%CI: 1.025-4.626,P=0.043) and progression (HR=2.130,95%CI: 1.123-4.038,P=0.021). Conclusion: NTC could improve the prognosis and reduce LNR of patients with stage ⅢA-N2 NSCLC, and LNR was expected to be a prognostic indicator.