Hormone-dependent leiomyosarcomas of the ductus deferens/epididymal tail complex appeared in virtually 100% of Syrian hamsters treated simultaneously with androgen and estrogen for approximately 400 days. Hypophysectomy did not prevent tumor induction. These tumors showed no change in hormone dependency after 60 serial passages. Neither hormone alone supported growth. Primary tumors and early transplants had a strongly fasciculated architecture and nucleoli were inconspicuous. By the sixth transfer, very prominent nucleoli became characteristic of the tumor cells and there occurred a rearrangement of fascicles into cords and columns. Concomitantly the latent period decreased from 200 to 40 days, approximately.
This investigation was supported by Public Health Service Research Grants No. CA-02791-08 and CA-04516-05 from the National Cancer Institute.