Microwave coagulation therapy on VX-2 carcinoma implanted in rabbit urinary bladders

In order to evaluate the effectiveness of microwave coagulation therapy on urinary bladder carcinoma, we conducted a series of experiments using carcinoma VX-2 cells designed for the application on animal hosts. Three days after implantation of VX-2 cells into the bladder of the rabbits, microwave coagulation therapy was performed. The antitumor effect, i.e. the survival rate, the histological study and the immunological response of the microwave therapy was examined in comparison with the control group (no treatment), the partially cystectomized group and the sham-operated group (no tumor cell implantation). The results were obtained as follows. (1) The survival rate in the microwave group was greater than that in the control group. (2) The stimulation index value (SI), which represents humoral immunity, decreased postoperatively in all groups. In the microwave group, SI increased gradually beginning 21 days after the transient decrease. (3) Histological findings revealed severe degeneration, necrosis and complete eradication of the cancer cells of the bladder wall in the microwave group, however, perforation of the urinary bladder could not be detected. The results indicate that microwave coagulation therapy is an effective procedure for urinary bladder tumors. Furthermore, microwave therapy may also accelerate the inactivation of immunological suppressors in the carcinoma host, an additional benefit of the microwave procedure.