Comparison of different induction therapy for locally advanced marginal resectable and unresectable esophageal squamous cell carcinoma and the prognostic value of subsequent conversion surgery: A real world study.

e16073 Background: The prognosis of locally advanced borderline resectable esophageal squamous cell carcinoma (BR-ESCC) and unresectable esophageal squamous cell carcinoma (UR-ESCC) is poor. Induction therapy makes it possible for downstaging of tumor to have a opportunity of radical resection, thus improving the prognosis. However, the optimal induction therapy remains under exploration, and the prognostic value of conversion surgery remains controversial. Methods: This was a retrospective study of patients with BR-ESCC and UR-ESCC who received chemotherapy (group CT), chemoradiotherapy (group CRT) and immunochemotherapy (group ICT) as the initial induction therapy. Based on induction therapy effect, patients received treatment with surgery (group ST), non-surgical treatment (group NST) and non-treatment (group NT). The outcomes included initial imaging efficacy, adverse events (AEs) of initial induction therapy and overall survival (OS). Results: The objective response rate (ORR) of the primary tumor lesions, ORR of the lymph nodes with a maximum short axis > 1.0 cm, tumor downstaging rate and the potential R0 resection rate after initial induction therapy were 49.7%, 36.4%, 40.0% and 54.1%, respectively. The ORR of lymph nodes in group ICT was significantly higher than that in group CT and group CRT (P = 0.015). The ORR of primary tumor lesions and downstaging rate in the group ICT were higher than those in group CT and group CRT, albeit without statistical significance (P > 0.05). Incidence rates of Grade 3 and higher AEs of three group were similar (P > 0.05). Group ST, compered to group NST, is significantly higher in terms of overall survival for patients with potential R0 resectable ESCC after induction therapy (P = 0.007), While there was no statistical difference in overall survival rate for the others (P = 0.271). Conclusions: ICT is superior to CT and CRT in terms of induction efficacy and the three exhibit similar incidence rates of adverse reactions. Treatment modalities involving conversion surgery are recommended in patients with potential R0 resectable ESCC after induction therapy. Non-surgical treatment is still a better option for the others.