Experimental immunotherapy of neoplastic pleural effusion with oil-attached BCG cell-wall skeleton in mice

An experimental model for neoplastic pleural effusion was made using a transplantable pleural fibrosarcoma MC-106 in ddO mice, and a local immunotherapy of neoplastic pleural effusion with oil-attached BCG cell-wall skeleton was attempted. Viable cells (3 X 10(5)) of MC-106 were injected into the right pleural cavity of the mice on day 0 with a tuberculin syringe which was joined to a two-way tap attached to a capillary manometer. All of the mice in the control group, which received intrapleurally saline solution 24 hr after the injection of tumor cells, died within 24 days and the mean survival time was 16.9 +/- 3.4 (SD) days. Macroscopically massive blooded pleural effusion in both pleural cavities and multiple tumor nodules on the surface of parietal and visceral pleura were observed. On the other hand, the mice which received intrapleurally 100 mug of oil-attached BCG cell-wall skeleton 24 hr after the injection of tumor cells survived much longer. About 50% of the mice remained alive and were killed on day 95. They revealed histologically no malignant lesion of the pleura except for residual changes of inflammatory reactions.