Pembrolizumab plus cisplatin and fluorouracil as induction chemotherapy followed by definitive chemoradiotherapy for patients with cT4 and/or supraclavicular lymph node metastasis (M1Lym) of esophageal squamous cell carcinoma.

Definitive chemoradiotherapy (DCRT) is administered as standard treatment for patients with cT4 and/or M1Lym esophageal squamous cell carcinoma (ESCC); however, its long-term result is inadequate. Although several studies have reported that conversion surgery can improve the survival of these patients, none have identified significantly better long-term survival than that achieved by DCRT. Thus, enhancing DCRT seems important to improve the survival of these patients. A strategy of shrinking tumor volume before DCRT and providing consolidation chemotherapy for systemic control is expected to improve the survival of these patients. Pembrolizumab plus cisplatin and fluorouracil has demonstrated good local control and significant improvement in the survival of patients with advanced esophageal cancer. Based on these results, the following strategy is proposed: This protocol should be applied as induction for these patients; then, DCRT should be provided depending on the initial response; and finally, adjuvant chemotherapy with an immune checkpoint inhibitor should be given to all responders.