Effect of whole-body microwave hyperthermia on delayed cutaneous hypersensitivity in tumor-bearing mice

Tumor-bearing and normal BALB/c mice were examined for their responsiveness to contact-sensitizing agent oxazolone after whole-body microwave hyperthermia treatment. The effective therapy with hyperthermia prolonging mean survival time of the animals and causing tumors regression resulted in strongly pronounced hyporeactivity to oxazolone. The impaired responsiveness remained unchanged until death of the tumor-bearing animals. In the case of tumor-free animals delayed cutaneous response returned to normal values within 8-12 days after hyperthermia treatment. It is documented that the longer exposure to hyperthermia sessions the more pronounced depression of reactivity to oxazolone occurs.