Effects of photodynamic therapy in combination with intravesical drugs in a murine bladder tumor model.

This study was designed to evaluate the interaction of photodynamic therapy (PDT) and intravesical drugs (thiotepa, adriamycin, mitomycin C and BCG) in a murine transitional cell carcinoma (MBT-2) model. C3H/He mice with implanted MBT-2 flank tumors were treated with either thiotepa (TT), adriamycin (ADM), mitomycin C, Bacillus Calmette-Guerin (BCG), photodynamic therapy (PDT) or a combination of the drug and PDT. The MBT-2 tumor showed sensitivity to adriamycin, MMC or PDT compared to control. PDT combined with either adriamycin, MMC or BCG, produced a greater retardation in the growth of the MBT-2 tumor than monotherapy with adriamycin, MMC, BCG or PDT. PDT combined with the anticancer agents currently used in intravesical therapy for bladder cancer is well tolerated. The combination of PDT and intravesical drugs may enhance the tumoricidal effect of either treatment used alone.