The role of the spleen in tumor bearing host: II. The influence of splenectomy in mice.

The effect of splenectomy on neoplastic outgrowth was examined prior to and after implantation of methylcholanthrene-induced C3H/He murine tumors. Splenectomy performed 12 days before tumor inoculation did not affect the tumor outgrowth, however, both splenectomy and sham operation performed shortly before tumor inoculation resulted in significant tumor facilitation compared with the non-operated group, suggesting that this accelerated tumor was not related to the presence or absence of splenic tissue, but rather to systemically-induced immunosuppression. While splenectomy performed 6, 9, 12 days after tumor inoculation did not alter the tumor growth, splenectomy performed early (3 days) or late stage (20 days) after tumor cell challenge revealed a retarded neoplastic outgrowth, compared with the sham operated group. These results suggest that splenectomy in very early and late stages of tumor-bearing host may be effective for tumor treatment.