Evaluation of immunotherapy with PSK in esophageal cancer

The cooperative study group of PSK for resected squamous cell carcinoma of esophagus was formed among 18 institutes in Japan to evaluate the efficacy of PSK. From February 1983 to November 1985, a total of 187 patients were entered into this study. Some 140 of them were judged to have received complete therapy. PSK was used as an immunopotentiator in combination with radiotherapy (I-A, I-B) and radiochemotherapy (II-C, II-D). The selection of radiotherapy or radiochemotherapy was entrusted to each institute. The two-year survival rates of I-A, I-B, II-C and II-D were 59.7%, 54.5%, 40.1% and 54.1%, respectively. From these observations, PSK was considered beneficial for esophageal cancer in combination with radiochemotherapy.