Inhibition of disease flare with diethylstilbestrol diphosphate and chlormadinone acetate administration for two weeks prior to slow-releasing leuprolide acetate in prostatic cancer patients.

To determine whether administration of estrogen or gestagen prior to luteinizing hormone-releasing hormone (LH-RH) agonist prevents disease flare in prostate cancer patients, we pretreated the patients with either diethylstilbestrol diphosphate (DES-P) 300 mg daily (N = 17) or chlormadinone acetate (CMA) 100 mg daily (N = 16) or none (N = 16) for two weeks before the initial injection of leuprolide acetate (L). Blood samples for prostatic specific antigen (PSA), testosterone (T), and luteinizing hormone were collected before CMA and DES-P administration, before and at 2, 7, 14, 28, 56, and 84 days after the first administration of leuprolide. The treatment with DES-P and CMA prior to LH-RH agonist induced an early decline of PSA. The mean PSA level showed no significant secondary rise in those patients with pretreatment after L administration. In the patients pretreated with DES-P or CMA, the mean serum T level never exceeded the pretreatment baseline after L administration. On the other hand, in the patients without DES-P or CMA, both serum T and PSA levels increased after the first administration of L. These results clearly demonstrate that pretreatment with DES-P 300 mg daily or CMA 100 mg daily for 2 weeks is quite effective to prevent disease flare after the first administration of L in patients with prostatic cancer.