Polymerised autologous tumor tissue particles in experimental cancer immunotherapy with special reference to the effects on the immune system of the host.

The efficacy of the specific active cancer immunotherapy utilizing autologous tumor tissue particles polymerised with ethylchlorformiate, and used in combination with the PPD tuberculin adjuvant, was studied in the mastocytoma (P-815 X2)-DBA/2 mouse system. Special attention was focused on the effects of the therapy on the immune system of the host as evaluated on the basis of the spleen white pulp morphology. The signs of tumor rejection by the host (tumor-surrounding fibrous scar, lymphocyte and plasma cell infiltrations, and disappearance of the tumor tissue) were most marked in mice receiving the specific immunotherapy. The specific cancer immunotherapy instituted was capable of reverting to a considerable degree the profound depletion of the T- and B-lymphocyte populations found in the spleen white pulp of mice not receiving any therapy for their tumor. Conclusion was drawn that the favorable influence on the tumor rejection exerted by the specific immunotherapy tested, most probably is attributable to its stimulatory effects on the cells responsible for both the cell-mediated and humoral immune reactions, the appropriate co-operation of both of which is needed to ensure the most effective host response against the tumor cells.