Treatment Strategy for Initially Unresectable Locally Advanced Esophageal Squamous Cell Carcinoma

Background Chemoradiotherapy (CRT) is the standard treatment strategy for initially unresectable locally advanced esophageal squamous cell carcinoma (ULA-ESCC) without distant metastasis. Salvage surgery after definitive CRT for ULA-ESCC cases is challenging in terms of both cure and safety. Methods For ULA-ESCC cases with no other noncurative factors, we start treatment with CRT and consider surgery when cT stage downstaging is obtained. Imaging evaluation of cT stage downstaging is performed initially at 40 Gy and then after completion of definitive CRT. Results In the multivariate analysis of 147 ULA-ESCC cases at our department, the responders at 40 Gy and surgical intervention after 40 Gy or definitive CRT were independent favorable prognostic factors. In the study of chemotherapy regimens used in CRT, DCF (docetaxel, cisplatin and 5-FU) therapy tended to be superior in both response and prognosis. We have recently treated some cases of ULA-ESCC with chemotherapy plus immune checkpoint inhibitor. Conclusion The significance of surgical intervention for ULA-ESCC should be carefully clarified. Clinical research on prognostic factors may be also important to improve the outcome of surgery.