[Adoptive immunotherapy against peritoneal metastases from stomach cancer--application of regional lymph node lymphocytes]

Abstract

Twenty-four patients with advanced stomach cancer were treated with OK-432 combined adoptive immunotherapy [AIT] as prophylaxis or therapy against peritoneal metastases. Lymphocytes isolated mainly from regional lymph nodes were cultured for 9-13 days with T cell growth factor and sonicated tumor extract. OK-432 administration and cell transfer were performed via a catheter inserted into the abdominal cavity at surgery. The proliferation rate of regional lymph node lymphocytes was higher than that of peripheral blood lymphocytes (p less than 0.01). Cultured regional lymph node lymphocytes expressed CD25 and CD4+45R- more frequently than those of peripheral blood lymphocytes. On the other hand, cytotoxic activity of regional lymph node lymphocytes were slightly lower than that of peripheral blood lymphocytes. These results suggest that regional lymph node lymphocytes could be used in AIT because of their different function from that of peripheral blood lymphocytes. Survival of the patients with peritoneal metastasis at primary laparotomy was higher than that of the historical control group (4-9 months after surgery). These results show that OK-432 combined adoptive immunotherapy appears to be a new therapeutic approach to peritoneal metastases from stomach cancer.