Serum prolactin levels in patients treated with a gonadotropin-releasing hormone analogue for adenocarcinoma of the prostate

Twenty-six patients with advanced cancer of the prostate were treated with [D-SER(BU(t))⁶]LHRH-(1-9) nonapeptide ethylamide (buserelin). All but 6 patients evidenced signs of metastasis. Blood prolactin levels were measured prior to the initiation of treatment and during a follow-up period of 18 months. A statistically significant (p > 0.0005) elevation in serum prolactin levels were observed after 3 months of treatment. Serum prolactin remained elevated for a total of 6 months, after which a decline of pretreatment levels was observed. Our observation of a transient rise in prolactin levels during the chronic administration of buserelin is at variance with previously published data which reported unchanged prolactin levels during such treatment.