Abstract: Objective To explore the efficacy of carilizumab combined with gemcitabine and cisplatin chemotherapy in patients with advanced lung squamous cell carcinoma (LSCC). 
Methods In total, 82 patients with advanced LSCC were divided into two groups according to the treatment plan. The control group consisted of 38 patients who received gemcitabine and cisplatin chemotherapy, while the observation group consisted of 44 patients who received treatment with combination therapy of carizolizumab on the basis of the control group. After 2 cycles of treatment, the short-term efficacy, drug toxicity, and tumor marker expression ［squamous cell carcinoma antigen (SCC Ag), cytokeratin 19 fragment antigen (CYFRA) 21-1, thyroid transcription factor-1 (TTF -1)］ of both groups were evaluated. They were followed up for 12 months, and the median overall survival (OS) and progression-free survival (PFS) of the patients were recorded. 
Results The objective remission rate of the observation group was 29.55%, which was higher than that of the control group (10.53%), and the disease control rate was 77.27%, which was higher than that of the control group (52.63%) (P＜0.05). After treatment, the serum levels of SCC Ag and CYFRA21-1 in both groups decreased compared with those before treatment, which were lower in the observation group than in the control group (P＜0.05). There was no significant difference in TTF-1 levels between the two groups after treatment (P＞0.05). There was no significant difference in the incidence of bone marrow suppression, gastrointestinal reactions, liver dysfunction, skin and mucosal toxicity, allergic reactions, and neurological toxicity between the two groups (P＜0.05). The median PFS of the observation group and the control group were 4 months and 3 months, respectively, and the median OS was 11 months and 7 months, respectively. The difference in PFS and OS survival curves between the two groups was statistically significant (Log rank χ2=9.937, 12.471, P＜0.05). 
Conclusion The combination of carilizumab and gemcitabine+cisplatin chemotherapy for advanced LSCC can improve the anti-tumor effect of patients, regulate the expression of tumor-related biomarkers, and has good safety. 

Key words: lung neoplasms, gemcitabine, cisplatin, carilizumab