Multimodal therapy for esophageal squamous cell carcinoma according to TNM staging in Japan—a narrative review of clinical trials conducted by Japan Clinical Oncology Group

Department of Gastroenterological Surgery, Tokai University School of Medicine, Isehara, Japan Contributions: (I) Conception and design: K Kanamori, K Koyanagi; (II) Administrative support: None; (III) Provision of study materials or patients: None; (IV) Collection and assembly of data: All authors; (V) Data analysis and interpretation: All authors; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. Correspondence to: Kazuo Koyanagi. Department of Gastroenterological Surgery, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, 259-1193, Japan. Email: kkoyanagi@tsc.u-tokai.ac.jp.