Ethylchlorformate polymerized tumor protein immunotherapy of the murine bladder tumor.

Using murine transplantable transitional cell carcinoma (MBT2), the effect of ethylchlorformate (ECF) polymerized tumor protein was compared with that of bacillus Calmette-Guerin (BCG). Seventy-five C3H/He mice were challenged with an intradermal inoculation of 5 X 10(5) viable MBT2 tumor cells and divided into five groups. Each group was intradermally administered with 0.01 mg of ECF (low ECF), 0.25 mg of ECF (high ECF), 0.1 mg of ECF and 10(6) CFU BCG (ECF/BCG), 10(6) CFU of BCG alone or normal saline (control) weekly for 10 weeks. The mean survival rate for the treatment groups was 64 to 73 days and significantly longer than that for the control group (P less than 0.001, Savage). The incidence of biologically active tumor progression was significantly less for the treatment groups (low ECF, 53%; high ECF, 33%; ECF/BCG, 7%; BCG, 27%) compared with the control group (87%; P less than 0.5, chi-square. The mean rate of tumor growth was significantly lower for all treatment groups than for the control group (P less than 0.001, ANOVA and SNK), and the ECF/BCG group had the lowest growth rate despite a higher incidence of local granulomatous reaction. In this study, immunotherapy significantly prolonged the survival rate, decreased the incidence of biologically active tumor progression, and slowed the rate of tumor growth. The combination of ECF polymerized tumor protein and BCG had the greatest effect, suggesting that the effect of the vaccine was increased with BCG.