Histologic and histochemical reactions in a mouse mammary carcinoma following exposure to combined heat-roentgen irradiation.

In mouse experiments a high curative effect on implanted tumours was obtained by successive application of low local heat and roentgen doses. Histologic and histochemical examinations of tumours so treated revealed a special reaction in the tissues. A total and rapid destruction of all hypoxic tumour tissue was observed and (in successful cases) a total blockade of all mitotic activity in euoxic tumour tissue was followed by a long-drawn necrobiotic decay of the existent tumour cells. The disturbances are electively bound to the tumour cells, only some normal tissues may secondarily be injured. A rapid and intensive lysosomal activity in all the tumour cells may probably be of importance in the reaction.