Enhancement of intermittent androgen ablation by "off-cycle" maintenance with finasteride in LNCaP prostate cancer xenograft model.

Background: Intermittent androgen ablation (IAA) was developed with the intention of delaying progression of prostate cancer to androgen-independence and improving quality of life. Our previous studies suggest that relative to dihydrotestosterone (DHT), testosterone (T) is a weak inducer of proliferation and a more potent inducer of differentiation. We hypothesize that administration of finasteride (F), a type-II 5-alpha-reductase inhibitor that increases T and decreases DHT, during the IAA "off-cycle" would enhance the efficacy.