Prostatic carcinoma treated with 2,6-cis-diphenylhexamethylcyclotetrasiloxane (Cisobitan).

Thirteen patients with stage III or IV carcinoma of the prostate were treated with 2,6-cis-Diphenylhexamethylcyclotetrasiloxane (Cisobitan, a new organosilicon compound. The drug proved to be a strong antiandrogen and exerted all the known effects of estrogens, including feminization and cardiovascular complications. It is therefore doubtful whether Cisobitan will be a reasonable alternative to estrogens in the treatment of patients with advanced prostatic cancer.