Phase II study of chemoradiotherapy with 5-fluorouracil and cisplatin for Stage II-III esophageal squamous cell carcinoma: JCOG trial (JCOG 9906) - Kato, K; Muro, K; Minashi, K; Gastrointestinal Oncology Study Group of the Japan Clinical Oncology Group (JCOG) (Int J Radiat Oncol Biol Phys, 2011)