Effect of splenectomy in tumor-bearing mice and gastric cancer patients.

In order to investigate the effect of splenectomy on tumor growth, splenectomy was performed in DDS mice transplanted subcutaneously with Ehrlich ascites tumor cells before and after the transplantation. It was found that, in the first control group receiving sham operation, all the mice died of tumor; in the second group that underwent splenectomy 1 week before the transplantation the tumor regressed in every case; in the third group that received splenectomy 5 days after transplantation when tumor became established, the tumor regression was observed in 85% of the animals, and in the fourth group that underwent splenectomy 10 days after transplantation, all the animals died of tumor earlier than the sham-operated first group. In the follow-up observations of 389 patients with gastric cancer who underwent gastrectomy alone and 89 cases who received gastrectomy combined with splenectomy, the 5-year survival rate of the latter group tended to show a better prognosis in a relatively early stage. It was concluded that splenectomy might inhibit the growth of tumor in a certain early stage, in both animals and humans, and the possible mechanism of this effect of splenectomy was discussed from the immunological aspects.