Experimental models for the study of prostatic adenocarcinoma.

The Dunning R3327H transplantable rat tumor is a well differentiated prostatic adenocarcinoma. The biological properties of this tumor have been characterized, and it appears that this animal model is well suited for studying the nature of prostatic cancer. The established tumor responds to castration therapy and this is subsequently followed by relapse to a predominant state of hormone insensitivity. Cell kinetic studies indicate that 70 to 90 per cent of the total tumor cells are hormonally sensitive, and a subpopulation of 8 to 30 per cent are hormone insensitive. The therapeutic relapse to androgen deprivation represents the continued growth of the clone of cells, which were hormone insensitive. It appears that this animal mimics the relapse of phenomenon observed in the hormone control of human prostatic cancer.