Correlation between size and external temperature of the ISIS 130 tumour after treatment with cytostatic agents.

The reduction in size of the experimental ISIS 130 tumour has been investigated in LOU rats under the influence of increasing doses of cytostatic agents belonging to different classes. External temperatures of tumours as well as rectal temperatures have been measured at the same time, twice daily, during the whole experiment. The greater the decrease in the tumour size after drug administration, the larger was the decrease in external temperature of tumour. The rectal temperatures remained fairly stable, thus differences between the tumour and rectal temperatures increased. A possible correlation between the reduction of tumour size and the decrease of external temperature of tumour has been traced for every cytostatic agent, and the same linear relationship has been found to link these two parameters. The decrease in external temperature of tumour may, moreover, predict the decrease in tumour size within a term of 1-2 days. Measurement of the magnitude of the transient tumour hypothermia of ISIS 130, following chemotherapy, would represent a new method for measuring the efficiency and duration of action of cytostatic agents.