Effect of oil-attached BCG cell-wall skeleton on the induction of pleural fibrosarcomas in mice.

The effect of oil-attached BCG cell-wall skeleton on the induction of pleural fibrosarcomas by 3-methylcholanthrene in mice was examined. The pleural fibrosarcomas were induced by a substernal injection of 3-methylcholanthrene into the thoracic cavity of ddO mice. One week after the injection of 3-methylcholanthrene, 100 mug of oil-attached BCG cell-wall skeleton was injected subcutaneously every week for 10 weeks. In the observation period of 130 days, the incidence of pleural fibrosarcoma was 67% in the control mice and 39% in the mice treated with BCG cell-wall skeleton. The latent period of tumor induction was prolonged in the mice treated with BCG cell-wall skeleton.