Bacillus Calmette-Guérin and dinitrochlorobenzene immunotherapy of chemically induced bladder tumors.

Immunologic incompetence is correlated with increased susceptibility to malignacy. Immunostimulation with such agents as Bacillus Calmette-Guérin (BCG) and dinitrochlorobenzene (DNCB) have resulted in regression of cutaneous maligancies. An evaluation of the effect of BCG and dinitrochlorobenzene sensitization and bladder irrigation in Fischer rats revealed no decrease in the incidence of bladder tumors induced by 2-formylamino-4-(5-nitro-2-furyl) thiazole (FANFT). However, direct intralesional injection of BCG into early bladder tumors was effective in preventing the progression of such tumors in seven of ten BCG-sensitized rats (P less than 0.005). No effect was seen when BCG was injected intralesionally in unsensitized rats or when control solutions were injected.