[Immunological significance of splenectomy in gastric cancer surgery. Production of immunosuppressive factor in the spleen].

We studied immunological significance of splenectomy in gastric cancer surgery with special reference to serum suppressor factor. The results showed that the sera from splenic venous blood in advanced gastric cancer was more suppressive to PHA blastogenesis of normal lymphocytes and also higher in the values of circulating immune complexes, as compared to the sera from peripheral blood. Furthermore, the media from cultures of spleen cells of patients with advanced gastric cancer indicated to suppress PHA blastogenesis of normal lymphocytes, as compared to the media from cultures of peripheral lymphocytes of the same patients. The suppressive activity was more increased in the media from cultures of nonadherent cell population obtained from the spleen cells. From these data, it was suggested that the spleen of patients with advanced gastric cancer was capable of producing serum suppressor factor. Therefore, gastrectomy combined with splenectomy may be reasonable in patients with advanced gastric cancer.