Combined therapeutic effects of an immunomodulator, PSK, and chemotherapy with carboquone on rat bladder carcinoma.

Responses of bladder cancer in ACI rats to combination therapy with an immunomodulator, PSK, and an alkylating agent, carboquone, are reported. PSK is a protein-bound polysaccharide isolated from Basidiomycetes, and carboquone is the alkylating agent 2,5-bis(1-aziridinyl)-3-(2-hydroxy-1-methanoxyethyl)-6-methyl-p- benzoquinone carbonate, molecular weight 3,214. The immunomodulator, PSK, was shown to enhance the effectiveness of the chemotherapeutic agent, carboquone. The therapeutic effect of combination treatment was monitored by measuring growth rates of tumors transplanted SC and by measuring decreases in metastatic spread to lungs in tumor-bearing animals. Effects of PSK on host immunity were monitored by measuring serum levels of immunosuppressive substance.