Enhanced metastasis formation by combined hyperthermia and hyperglycemia in rats bearing Walker 256 carcinosarcoma

Hyperglycemia has been shown to decrease tumor pH and blood flow rates, consequently this could increase the sensitivity of tumor to hyperthermia. Combined waterbath hyperthermia (43 degrees C/2 h) and hyperglycemia (6 g/kg, i.p.) was investigated on survival of rats bearing a metastasizing form of Walker 256 carcinosarcoma. Hyperthermia alone increased the survival rate of animals from 19% to 42%. Hyperglycemia promoted more uniform tumor heating in the foot. However, combined hyperthermia and hyperglycemia led to a significant decrease in the survival rate of animals (10%; P less than 0.001), and most rats died with widespread metastasis in lymph nodes, lungs and kidneys. These findings do not support the postulate that hyperglycemia leads to sensitization of tumor destruction by hyperthermia.