Safety and efficacy of living BCG or BCG cell walls (CW) in the treatment of guinea pig hepatoma.

Guinea pigs with established intradermal tumors and microscopic lymph node metastases were treated by intralesional injection of graded doses of living BCG or BCG CW. The lowest dose of living BCG used produced a significant cure rate and no grossly evident toxicity. An intermediate and the highest dose of living BCG used cured some animals but others lost weight and a significant number died as a result of the treatment. Histologic examination of animals with significant weight loss showed fatty degeneration of the liver, granulomatous hepatitis and histiocytic infiltration of the spleen. None of the doses of BCG CW used was toxic and they were at least as effective as living BCG in intralesional treatment. In some experiments in which treatment was delayed it was found that the extent of disease required to render treatment ineffective was about the same for living BCG and for BCG CW.