Effect of a Progesterone Compound on Growth of a Transplanted Granulosa Cell Tumor. ∗

Abstract

Progesterone has been considered to be inhibitory to, or without effect on, tumor growth. Heimann 1 reported a marked decrease in incidence of mammary carcinoma in the RIII strain of mice treated with progesterone alone and a still lower incidence when this was combined with testosterone. He stated, however, that it did not prevent growth of transplanted tumors in mice. He also found^1b that it inhibited growth of adenomatous portions of breast fibroadenomata and decreased the number of takes of auto- and homo-transplants in rats. There was no effect on fibroma, myxoma, or sarcoma or on adenomatous growth in pregnant or castrated rats. In the guinea pig Lipschütz and Vargas 2 observed decrease in size, and actual disappearance, of the fibroids caused by oestrogen. Burrows and HochLigeti, 3 however, found no change in incidence of mammary carcinoma in mice injected weekly with 1 mg of progesterone, and Loesser 4 found slight, if any, improvement in animals or patients with breast carcinoma treated with progesterone.

The effects of larger amounts of progesterone on tumor growth have been studied, using a material containing a high concentration of progesterone.§ Preliminary experiments indicated a growth-stimulating effect on mammary carcinoma in mice. 5 A study of the effect of this material on a transplanted ovarian tumor was then undertaken, Subcutaneous transplantation of a granulosa cell tumor induced by intrasplenic transplants 6 in mice of the C57 strain had been attempted.

Growth of one of the transplanted tumors occurred but rarely and only after a long time in intact or castrated animals with and without estrogen treatment. In castrated animals treated with the crude progesterone, growth of the tumor occurred in some cases within 10 days. Subsequent study has confirmed this finding plus additional information.