The paradoxical effects of splenectomy on tumor growth
Abstract
Background: There is a vast and contradictory literature concerning the effect of the spleen and particularly of splenectomy on tumor growth. Sometimes splenectomy seems to inhibit tumor
growth, but in other cases it seems, paradoxically, to facilitate both oncogenesis and the growth of
established tumors.
Approach: In this essay I have selected from this large literature a few papers that seem particularly instructive, in the hope of extracting some understanding of the rules governing this paradoxical behavior.
Conclusion: In general, whether splenectomy enhances or inhibits tumor growth seems to depend primarily upon the ratio of spleen to tumor. Small proportions of spleen cells usually
stimulate tumor growth, in which case splenectomy is inhibitory. Larger proportions of the same cells, especially if they are from immunized animals, usually inhibit tumor growth, in which case
splenectomy results in tumor stimulation.