Immunotherapy for esophageal cancer. A randomized trial in combination with radiotherapy and radiochemotherapy. Cooperative Study Group for Esophageal Cancer in Japan.

We investigated the effect of multimodal therapy in 187 patients with esophageal cancer. All patients were followed up over a period of 5 years. Among the 187 patients, 174 (93.1%) eligible patients with biopsy-proved esophageal squamous cell carcinoma underwent esophagectomy and were randomly assigned to receive radiotherapy (RT) with or without protein-bound polysaccharide (PSK), or RT plus chemotherapy (CT) with or without PSK. The 5-year survival rates of patients with RT, RT+PSK, RT+CT and RT+CT+PSK were 40.0%, 42.3%, 29.1% and 37.2%, respectively. There was a tendency for longer survival on PSK, but statistical significance was not reached (RT+CT group versus RT+CT+PSK group: log-rank and generalized Wilcoxon tests, P = .1930, P = .1034). However, Cox multivariate regression analysis indicated that postoperative therapy with or without PSK was the most significant prognostic factor for patients receiving RT+CT and for the eligible patients. These results indicate that PSK may have a beneficial effect on esophageal carcinoma when given in combination with CT+RT.