Protection against spontaneous mouse mammary adenocarcinoma by inoculation of heat‐treated syngeneic mammary tumor cells

Abstract

The purpose of the study was to determine the effect of the inoculation of syngeneic mouse mammary tumor cells on the incidence of spontaneous tumors and mortality in a group of RIII female mice which normally have a high incidence of primary breast tumors. Animals were inoculated with either untreated, heat‐treated or irradiated tumor cells or a combination of cells. One group received no injections and served as a control.The incidence of tumor development and mortality was recorded for each animal used in the study. Significant delays in tumor onset and subsequent death of the animals were noted in those groups that had been injected with heat‐treated cells as compared to those animals that had been inoculated with non‐heated cells (either irradiated or untreated) or the untreated controls. No detectable differences were found between the groups receiving non‐heated cells and the untreated control group.It was found that the protection derived from inoculation of heat‐treated tumor cells was not due to decreased tumor growth rate, but was more probably related to the destruction of a portion of the tumor cell population.