Immunological Studies on the Esophageal Cancer and Gastric Cancer : Natural Killer Activity and Serum Immunosuppressive Acidic Protein Level

Natural Killer (NK) cells show the cytotoxicity for various target cells without any sensitization in vitro. Immunosuppressive acidic protein (IAP) is an immunosuppressive factor in the serum of the cancer patients. In the present study, NK activities of the peripheral blood lymphocytes and serum IAP levels of the patients with esophageal cancer or gastric cancer, were examined before and after surgical operation. NK activities of the lymphocytes in the spleen, regional lymph nodes and tumor of these patients were also studied. The decrease of NK activitiy of the peripheral blood lymphocytes and the increase of serum IAP level before surgical operation were observed in the stage IV patients with esophageal cancer or gastric cancer. Surgical curability had relation to NK activities of the peripheral blood lymphocytes and serum IAP levels before operation. In the postoperative course, the changes of NK activity and serum IAP level ran paralleled to the prognosis of the patients. Lymphocytes in the regional lymph nodes and tumor showed significantly lower NK activities in comparison with lymphocytes in the peripheral blood and spleen.