Effect of Schistosoma mansoni and cyclophosphamide on a mouse fibrosarcoma

Groups of B10A mice bearing a fibrosarcoma were treated with agents that induce eosinophilia such as cyclophosphamide (CY) or Schistosoma mansoni antigen (SMA) or both, and the growth of their tumors was evaluated. Tumor growth was most markedly attenuated in the group of mice that had 4 pairs of S. mansoni implanted in their backs 5 days before injection of tumor cells and then received SMA twice a week. These animals had tumor growth reduced by 90%. CY alone had no effect on tumor growth. In groups treated twice a week with SMA alone or associated with CY on day -2, tumor growth was reduced by 26% and 40%, respectively.