Simultaneous administration of a luteinizing hormone releasing hormone agonist and diethylstilbestrol in the initial treatment of prostatic cancer.

It is well known that the first administration of luteinizing hormone releasing hormone (LH-RH) analogues induces an initial increase of luteinizing hormone (LH) release and a subsequent rise in testosterone (T). This rise is maximal after 3-4 days and is followed by a steady fall of LH and T. Several investigators have reported flare-up symptoms in patients with advanced prostatic cancer, associated with the rise of T, when treated by LH-RH analogue alone. In order to prevent these flare-up symptoms, we treated 20 patients with advanced prostatic cancer with an association of a LH-RH analogue (Zoladex Depot) and diethylstilbestrol (DES) 1 mg/day. DES was given for 14 days, starting 7 days before the first Zoladex Depot injection. T fell to near castrate levels within a few days, but rose again 3-4 days after the administration of the LH-RH analogue to pretreatment values before returning to castrate levels. No clinical flare-up manifestations were recorded. We conclude that combination treatment with DES can prevent the flare-up symptoms induced by LH-RH analogue in patients with prostatic cancer.