Correlation between lymph node metastasis rate and prognosis in non-small cell lung cancer patients with stage Ⅲ A/N 2 / 肿瘤研究与临床

ABSTRACT

Objective:To explore the correlation between lymph node metastasis rate and prognosis in non-small cell lung cancer (NSCLC) patients with stage Ⅲ A/N 2. Methods:The clinical data of 350 NSCLC patients with stage Ⅲ A/N 2 receiving surgical treatment from January 2012 to June 2015 in Shanxi Provincial Cancer Hospital were retrospectively analyzed. The patients were divided into the high lymph node metastasis rate group and the low lymph node metastasis rate group according to the optimal cutoff value of lymph node metastasis rate determined by Cox hazard regression model. The relationship between clinicopathological features and lymph node metastasis rate was analyzed. Prognostic risk factors were analyzed by using Cox regression model, and overall survival (OS) and disease-free survival (DFS) of both groups were analyzed by using Kaplan-Meier method. Results:The optimal cutoff value of lymph node metastasis rate was 0.2. There were 180 cases with high lymph node metastasis rate (>0.2) and 170 cases with low lymph node metastasis rate (≤0.2). The proportion of the patients with adenocarcinoma and the highest lymph node metastasis in the high lymph node metastasis rate group was higher than that in the low lymph node metastasis rate group [72.2% (130/180) vs. 52.9% (90/170), 52.8% (95/180) vs. 29.4% (50/170), all P<0.05]. The proportion of patients with jumping N 2 lymph node metastasis, single station N 2 lymph node metastasis and single station N 2 lymph node metastasis in the highest group was lower than that in the low lymph node metastasis rate group [51.1% (92/180) vs. 71.8% (122/170), 25.0% (45/180) vs. 44.1% (75/170), 38.9% (70/180) vs. 75.3% (128/175), all P<0.05]. Cox multi-factor regression model analysis showed that adenocarcinoma, multiple stations N 2 lymph node metastasis, lymph node metastasis rate were independent risk factors of DFS for NSCLC patients with stage Ⅲ A/N 2 ( HR = 2.201, 95% CI 1.444-3.355; HR=2.971,95% CI 1.950-4.529; HR=3.543, 95% CI 1.874-6.699; all P<0.05). Lymph node metastasis rate was an independent risk factor of OS for NSCLC patients with stage Ⅲ A/N 2 ( HR = 3.669, 95% CI 1.941-6.938, P<0.05). The 5-year OS rate of the low lymph node metastasis rate group was higher than that of the high lymph node metastasis rate group (64.00% vs. 36.58%, χ2 = 11.422, P = 0.001). The 5-year DFS rate in the low lymph node metastasis rate group was higher than that in the high lymph node metastasis rate group (45.00% vs.18.32%, χ2 = 13.624, P<0.01). Conclusion:Lymph node metastasis rate is an independent influencing factor for the prognosis of NSCLC patients with Ⅲ A/N 2 stage, and it can effectively evaluate the prognosis.