Comparison of the Efficacy of Intravesical Bacillus Calmette-Guérin with Thiotepa, Mitomycin C, Poly I:C/Poly-L-Lysine and Cis Platinum in Murine Bladder Cancer

Abstract

The efficacy of intravesical BCG for the treatment of the mouse bladder tumor MBT-2 was compared with that of thiotepa, mitomycin C, cis-diamminedichloroplatinum II and poly I:C/poly-L-lysine. MBT-2 cells were instilled into the bladder immediately after electrocauterization. Drug instillations were initiated 24 h later and continued on a weekly basis for 4 wk. Both BCG and cis-diamminedichloroplatinum II significantly (P < 0.0004) inhibited MBT-2 tumor implantation when compared to diluent-treated controls. Neither mitomycin C, thiotepa nor poly I:C/poly-L-lysine significantly inhibited tumor implantation. Mean tumor weights also were significantly (P < 0.05) reduced in BCG and cis-diamminedichloroplatinum II-treated mice, while tumor mean weights in mice treated with thiotepa, mitomycin C or poly I:C/poly-L-lysine were not significantly different than controls. The efficacy of intravesical BCG in comparison with other drugs in the MBT-2 mouse bladder tumor model is probably similar to observations reported in human clinical trials in which intravesical BCG was shown to be more effective than other cytotoxic drugs. The utility of the MBT-2 model for the study of the mechanisms by which BCG inhibits bladder tumor growth was supported.