Experience with Intrafemoral Transplant of Breast Tumor in Rats. ∗

Abstract

A technique whereby tumor cells can be introduced into the medullary cavity of the rat femur has been reported(l). This report describes the successful growth of mammary tumor in the same site.

Method and material. The experiments fell into two phases.

Phase I. Sprague-Dawley female rats were divided into 2 groups of 20. The first group received an homologous suspension of DMBA-induced breast cancer cells. Following the inoculation the tumor failed to grow, was at no time radiologically demonstrable and no viable tumor cells remained when the femora were histologically examined.

The second group received an autologous suspension of DMBA-induced breast cancer cells. All the animals in this group developed lytic lesions in the femur, well shown radio-logically and confirmed by histology. The difficulty, however, of establishing a uniform group of animals where inoculation of the femur could be performed in a fixed number, at a fixed time, with the same tumor, led us to seek another strain of animals. The inbred Wistar-Furth rat, in which a well-established breast tumor is easily transplanted and grows within a few weeks, was therefore chosen for the next phase. This allowed preparation of a uniform breast tumor suspension that could be used for inoculation of a group of animals. Phase II. Two major groups of transplant-able breast tumor are available with the Wistar-Furth animals: 1. A highly autonomous tumor. 2. A hormone-dependent tumor. These have been described by Kim(2) and it was decided ideal to see if the transplant-able tumors of type 2 could be utilized. Using the Wistar-Furth rats would thus eliminate the induction time of the tumor, a standard cell group could be used for each batch of rats and alterations of hormone environment, drugs and cytotoxic agents on the bone tumor, which is the main aim of the work, could be studied.