[Effect of BCG on the growth rate of Sarcoma in normal and splenectomized mice]

A study was carried out on the growth of Sarcoma 180 alone or mixed with BCG in normal and splenectomized BALB/c mice, with or without previous immunization with BCG intradermally (id), 40 days before tumor challenge. No survival was observed in non splenectomized mice inoculated with Sarcoma 180, both in normal mice and in those previously treated with BCG, whereas the inoculation of Sarcoma 180 mixed with BCG produced a 37 % increase in the survival rate in normal animals and an 83 % increase in the group previously treated with BCG. In splenectomized mice the survival rate was 56 % in those inoculated with Sarcoma 180 alone, rising to 100 % in the group inoculated with Sarcoma 180 mixed with BCG. Previous immunization with BCG in splenectomized animals did not affect tumor incidence significantly. These results suggest the participation of the spleen in the mechanism of tumoral rejection favoured by BCG inoculation.