Effect of prophylactic and therapeutic administration of BCG vaccine on growth of experimental sarcoma.

The effect of prophylactic and therapeutic administration of BCG vaccine on growth of transplantable sarcomas induced by MSV-Harvey (MSVT1) and 3-methylcholanthrene (MC 11 and MC 12) in C57BL/10Sn mice was studied. Growth of MSVT1 sarcomas was not inhibited by oral or intratumoral BCG therapy. Nor was prophylactic oral administration of BCG followed by therapeutic oral BCG treatment effective. On the other hand, intradermal administration of an adequate dose of BCG vaccine preceding the tumour transplantation inhibited tumour growth. The low (0.05-0.2 mg.) doses of BCG induced resistance comparable to the effect of subcutaneous immunization with tumour cells, whereas the higher (0.5-1.0 mg) doses had no effect. Growth of MC 11 and MC 12 tumours was not affected by prophylactic intradermal BCG administration.