Chapter 21. Luteinizing Hormone Releasing Hormone (LHRH) Analogues

Ten patients with prostatic carcinoma--six with stage C and four with stage D disease--were treated for 6 weeks to 12 months with agonistic analogues of luteinizing hormone-releasing hormone (LH-RH). [D-Trp6]LH-RH was given subcutaneously once daily at a dose of 100 microgram and [D-Ser(But)6]des-GlyNH2(10)-LH-RH ethylamide (HOE 766) was given subcutaneously (50 microgram once daily) or intranasally (500 microgram twice daily). In all patients, mean plasma testosterone levels showed a 75% suppression by the third week of treatment and remained low thereafter. This was followed by a decrease or normalization of plasma acid phosphatase levels by the second month of treatment and a 47% decrease in serum alkaline phosphatase by the 10th week of treatment in all but one patient. In patients with stage C disease presenting with prostatism or urinary outflow obstruction, there was a noticeable clinical improvement. In two such patients, a decrease in the size of the prostate was confirmed by ultrasonography. In patients with stage D disease manifested by diffuse bone metastases, there was relief of bone pain, and in one patient treated for greater than 12 months the improvement was documented by radioisotope bone imaging. It is concluded that superactive agonistic LH-RH analogues hold promise as therapeutic agents in patients with androgen-sensitive prostatic adenocarcinoma. Furthermore, the analogous of LH-RH may be used to assess the responsiveness of patients to surgical castration. Long-term administration of LH-RH analogues could become an alternative to surgical castration and estrogen therapy for the treatment of hormone-dependent prostatic carcinoma.

Congenital adrenal hyperplasia (CAH) is a recognized cause of precocious pseudopuberty. Some children with CAH also develop true precocious puberty with early maturation of the hypothalamic-pituitary-gonadal axis. We have seen four such children (three boys and one girl) who had the diagnosis of CAH made between the ages of 3 and 6 yr. These patients were treated with standard doses of hydrocortisone and fludrocortisone. A diagnosis of true precocious puberty was made because of testicular enlargement in the boys, breast development in the girl, progressive pubic hair development, rapid growth, and rapid bone age maturation. Plasma steroid levels were elevated for age, and gonadotropin levels were within the normal pubertal range, both basally and in response to LHRH stimulation. We treated these children with daily sc injections of a LHRH analog (LHRHa) for 6-18 months in addition to the standard hydrocortisone and fludrocortisone therapy for CAH. LHRHa significantly decreased basal plasma LH and FSH, peak LH and FSH responses to native LHRH, and testosterone levels. Testis size decreased in the males, and breast development regressed in the female. LHRHa therapy led to significant decreases in linear growth rate, ulnar growth rate, and rate of bone age advancement. These results suggest that LHRHa is an effective adjunct to hydrocortisone and fludrocortisone in the treatment of true precocious puberty complicating CAH.