EFFECT OF EARLY EXPOSURE OF FLUTAMIDE ON SUBSEQUENT GROWTH OF TRANSPLANTABLE RAT PROSTATIC TUMOR (DUNNING R-3327)

Rat transplantable prostatic tumors (Dunning R-3327) were treated with flutamide before tumors grew palpable, in order to examine the effect of short term treatment of antiandrogen for prostatic cancer in laten t period on the growth after appearance of tumor. Flutamide delayed an appearance of the tumor nodule and retarded the growth rate in propor tion as treatment began earlier. Flutamide also reduced final tumor vo lume. Flutamide-treated tumors histologically consisted of small or di lated glandular structure with an increase in stromal area, but androg en receptors were preserved. Flutamide-treated tumor showed slow growt h with androgen sensitivity when transplanted to intact rats, showing prolonged influences of antiandrogen on tumor growth. There was no sig nificant difference between flutamide-treated and control groups in we ight of accessory sex organs and serum androgen or estrogen levels. In conclusion, flutamide treatment may retard an appearance of prostatic cancer concomitant in benign prostatic hyperplasia. (C) 1994 Wiley-Li ss, Inc.