A total of 66 patients were enrolled in this exploratory study and randomly assigned to cohort 1 and cohort 2, with 33 patients in each group. Cohort 1: Neoadjuvant therapy (benmelstobart combined with chemotherapy and anlotinib, 3 cycles, every 21 days is a cycle). Surgery was performed 4-6 weeks after the final administration of benmelstobart as assessed by the investigator. Adjuvant therapy was evaluated by the investigator 4-6 weeks after surgery. Patients who achieved R0 resection received adjuvant therapy (benmelstobart combined with anlotinib, 12 cycles, every 21 days is a cycle). Cohort 2: Neoadjuvant therapy (benmelstobart combined with chemotherapy, 3 cycles, every 21 days is a cycle). Surgery was performed 4-6 weeks after the final administration of benmelstobart as assessed by the investigator. Adjuvant therapy was evaluated by the investigator 4-6 weeks after surgery. Patients who achieved R0 resection received adjuvant therapy (benmelstobart, every 21 days is a cycle) .