【Abstract】Background: Small cell lung cancer (SCLC) is a common pathological type of lung cancer. Almost all patients with SCLC also relapse after achieving a complete response with first-line treatment. The role of second-line treatment strategies in SCLC has been a subject of extensive research and debate. Objective: To summarize the impact of regimens containing irinotecan in second-line or subsequent therapies on the overall survival (OS) of small cell lung cancer patients. Methods: We reviewed extensive stage SCLC patients at Wangjing Hospital of CACMS who had received irinotecan monotherapy or combination with others anti-tumor drugs from January 2016 and December 2023 as second-and subsequent-line treatment. Results: A total of 73 patients were included in the final analysis. The median overall survival (OS) time for irinotecan used as second-line therapy was 7.47 months. Hypertension and hepatic dysfunction were the most pronounced adverse events of combination therapy and two patients changed regimens due to severe fatigue and anorexia. Conclusions: The combination of bevacizumab and irinotecan effectively alleviate brain metastasis in small cell lung cancer and can prolong OS in second-line therapy.