Abstract: Objective   To explore the influencing factors of disease-free survival(DFS) in patients with stage Ⅲ non-small cell lung cancer (NSCLC) after neoadjuvant chemotherapy combined with immunotherapy.  Methods   A total of 200 patients with stage Ⅲ NSCLC undergoing radical operation after neoadjuvant chemotherapy combined with immunotherapy in the hospital were enrolled between May 2014 and May 2019.All were followed up for 3 years after neoadjuvant chemotherapy combined with immunotherapy.According to 3-year DFS,they were divided into DFS group (n=76) and non-DFS group (n=124).DFS was analyzed by Kaplan-Meier method,and its influencing factors were analyzed by Cox regression model.  Results   In the 200 patients,there were 96 cases (38.00%) with 3-year DFS,and the median DFS was 21 months.The differences in smoking history,differentiation degree,tumor diameter,EGFR gene mutation,expression of ALK gene,curative effect of neoadjuvant chemotherapy combined with immunotherapy,and postoperative adjuvant chemotherapy between the two groups were statistically significant (P<0.05).The analysis of Cox regression model showed that smoking history (OR=2.016,P=0.004),low differentiation (OR=2.125,P=0.001),tumor diameter >3 cm (OR=1.958,P=0.007),EGFR gene mutation (OR=2.305,P=0.002),positive expression of ALK gene (OR=2.450,P=0.004) and non-remission after neoadjuvant chemotherapy combined with immunotherapy (OR=1.820,P=0.005) were risk factors of DFS,while postoperative adjuvant chemotherapy (OR=1.728,P=0.006) was a protective factor.  Conclusion   In patients with stage III NSCLC undergoing radical operation after neoadjuvant chemotherapy combined with immunotherapy,DFS is related to smoking history,differentiation degree,tumor diameter,EGFR gene mutation,expression of ALK gene,curative effect of neoadjuvant chemotherapy combined with immunotherapy and postoperative adjuvant chemotherapy.

Key words: non-small cell lung cancer, stage Ⅲ, neoadjuvant chemotherapy, immunotherapy, disease-free survival