Intranasal nafarelin: an LH-RH analogue treatment of gonadotropin-dependent precocious puberty

Hematometrocolpos in an adolescent female treated for pelvic Ewing sarcoma

Radiation therapy is often used to achieve local control of pelvic Ewing sarcoma in children. The effects of radiation on the female reproductive tract have been well documented in adults with gynecological malignancies, but the long-term consequences of pelvic radiation in pre-pubertal or adolescent girls are not as well described. We report a case of hematometrocolpos developing in an adolescent previously treated with chemotherapy and radiation therapy for pelvic Ewing sarcoma. We describe the clinical presentation, radiographic features, gross pathology, treatment strategies, outcome, as well as putative predisposing factors and preventative interventions.

Precocious puberty

Puberty occurring before the age of 8 years in girls and 9 years in boys in considered precocious. The numerous causes of precocity can be classified as central or peripheral. Central or true precocious puberty (CPP) is due to premature activation of the hypothalamopituitary-gonadal axis and is isosexual. Peripheral or pseudoprecocious puberty (PPP) results from the production of sex steroids independent of the H-P-G axis and may be isosexual or heterosexual. CPP is the most common form of precocity involving more than 50% of children and is much more common in girls than boys. CPP is more common between 4 and 8 years. A peak serum LH levels > 10 iu/l following GnRH stimulation is the absolute evidence of CPP. Serum IGF-I levels are predictive of the outcome. Availability of CT and MRI has helped to determine the cause of CPP in most cases. Hypothalamic hamartoma is the most common tumour causing CPP especially in boys. Adrenal causes, particularly CAH, are the commonest cause of PPP in boys whereas ovarian causes are more likely in girls. Long acting GnRH analogues provide a safe and effective form of treatment of CPP.

Gonadotropin-releasing hormone agonist analog (nafarelin): a useful diagnostic agent for the distinction of constitutional growth delay from hypogonadotropic hypogonadism

To determine the usefulness of a GnRH agonist analog as a diagnostic test to distinguish between constitutional delay of growth (CGD) in boys with Tanner stage I of sexual development and patients with hypogonadotropic hypogonadism (HH), we evaluated six boys (mean age 15 yr 4 m) and five HH patients (mean age 20 yr 4 m). In addition, 20 normal healthy men aged 21 yr to 50 yr received either nafarelin or GnRH followed two weeks later by the other test in order to compare the efficacy of each of these tests and to evaluate the optimal sampling times for the nafarelin test. All subjects were healthy, and had not received hormonal replacement for at least 2 months prior to enrollment in the study. Each man had four baseline blood samples before and at timed intervals following the administration of either GnRH or nafarelin. Each of the patients had blood withdrawn every 15 min during 12 h overnight followed by a single s.c. injection of nafarelin (1 microgram(s)/kg up to 100 microgram(s)), except two HH patients who did not have an overnight study. Blood samples were obtained at timed intervals for 24 h. LH, FSH, T and E2 were measured by RIA. Baseline concentrations of plasma LH, FSH and T were similar before the administration of either GnRH or nafarelin in the group of normal men. Peak stimulation of plasma LH, FSH and T released by nafarelin was significantly higher, and it took a longer time to reach the peak maximum, than after GnRH (p < 0.001). Mean nocturnal LH was 5.5 +/- 0.9 IU/I for the CGD group, and 2.7 +/- 0.7 IU/I for HH (p < 0.02). Mean nocturnal FSH was 5.1 +/- 1.0 and 2.5 +/- 0.2 IU/I whereas mean nocturnal T concentrations were 4.2 +/- 0.8 and 0.7 +/- 0.2 nmol/I (CGD vs HH, respectively, p < 0.02). Peak LH responses to nafarelin were 36.9 +/- 8.9 IU/I for the CGD group, and 7.0 +/- 2.0 IU/I for the HH group (p < 0.001). Peak FSH released by nafarelin was 14.2 +/- 2.4 IU/I for the CGD group and 4.8 +/- 2.0 IU/I for the HH group (p < 0.02). Peak T was reached 24 h following nafarelin injection and was 5.7 +/- 1.7 nmol/I for the CGD group and 0.3 +/- 0.2 nmol/I for the HH group (p < 0.001). The results obtained indicate that in early stages of puberty (before detectable changes of sexual maturation) the nafarelin test, with measurements of LH, FSH and T in blood or in urine, is superior to and more practical than overnight hormonal estimates to clearly distinguish CGD from HH.

Variations in pituitary-gonadal suppression during intranasal buserelin and intramuscular depot-triptorelin therapy for central precocious puberty. Belgian Study Group for Pediatric Endocrinology

This study evaluated pubertal development, growth and pituitary-gonadal suppression in 21 patients with central precocious puberty treated with buserelin intranasally and switched after a mean of 2.1 yr to depot-triptorelin given im for 1 year. Arrest or regression of puberty was observed in 12 patients while progression of puberty during therapy was seen in 9 patients (6 on buserelin, 2 on triptorelin and 1 on both therapies). The increment in serum LH and FSH concentrations after sc injection of short-acting triptorelin was greater on buserelin than on triptorelin therapy, particularly in patients with evidence of progression of puberty. Height velocity during therapy showed a reduction which paralleled the decelerating phase of the normal pubertal growth spurt. The rate of bone maturation during therapy was inversely related to pretreatment bone age. Predicted final height showed marked individual variations which were inversely related to predicted adult height before therapy. These data indicate that differences in the nature and route of administration of Gn-RH agonist therapy for central precocious puberty can be of importance for inhibition of pituitary gonadotropin secretion and development of secondary sex characteristics. Height velocity and bone maturation are age-related and the change in predicted adult height depends on pretreatment level.

Developments in the control of testicular function

Clinicians and clinical investigators have developed improved means for controlling testicular function in men. New and refined approaches for stimulation and inhibition of the hypothalamic-pituitary-testicular axis are now available. This chapter reviewed the most successful ways to inhibit the reproductive axis in men and its current application to the treatment of precocious puberty, metastatic prostate cancer, benign prostate hyperplasia and as prospective male contraceptives. Safe, effective and reversible medical approaches to male contraception are now approaching reality. Azoospermia and severe oligozoo/azoospermia can now be accomplished in the majority of men with combined GnRH antagonists and replacement doses of testosterone. Androgens and androgen-progestogen concentrations will induce azoospermia in over 90% of Asian men and azoospermia or severe oligospermia in Caucasian ethnic groups. Field trials are ongoing to determine whether testosterone administration will be more effective than condoms as contraceptives. True precocious puberty can now be managed more effectively than in the past by suppression of gonadotropin secretion with GnRH analogues. Precocious puberty due to other causes can be treated more effectively with inhibitors of steroidogenesis and blockers of androgen action. Metastatic prostate cancer, previously treatable with either castration or oestrogens, is now amenable to suppression of androgen secretion. GnRH analogues are given either alone or combined with blockers of androgen action. While significant palliative effects are observed with endocrine ablative therapy in most men with Stage C or D prostate cancer, modest increases in duration of survival may be seen. Benign prostate hyperplasia was previously approachable only with surgical intervention. Recent data have suggested that medical treatment with 5 alpha-reductase inhibitors and/or selective alpha-adrenergic blockers may offer non-surgical alternatives in some patients. More data are needed to determine the role of medical management of this common disorder.

Preserving adult height potential in girls with idiopathic true precocious puberty

We designed a prospective study of height potential in girls with idiopathic precocious puberty, comparing the presenting features of girls with and without evidence of reduced adult height potential. The 14 girls with impaired adult height prognoses (group 1) were reexamined after treatment with a gonadotropin releasing hormone agonist, nafarelin. The seven girls with the prognosis of unimpaired height (group 2) were followed without therapy. We found that the group could be distinguished at initial examination by the greater bone age/height age ratio of group 1 (mean +/- SEM: 1.4 +/- 0.06 vs 1.0 +/- 0.05; p less than 0.005) and by the greater difference between predicted height and target height in group 1. The mean predicted height in group 1 was significantly less than the mean target height (150.7 +/- 2.1 vs 165.4 +/- 3.0 cm; p less than 0.005), whereas the mean predicted and target heights in group 2 were similar (165.4 +/- 3.0 vs 164.3 +/- 2.1 cm). Initial estradiol levels were also greater in group 1 than in group 2 (21.6 vs 10.6 pg/ml; p less than 0.05), although this difference was not sustained during follow-up. In group 1, nafarelin therapy suppressed the pituitary-gonadal axis, and although there was a transient reduction in height potential in girls with the youngest bone ages during the first 6 months of therapy, 2 years of treatment slightly improved predicted heights from 150.7 +/- 2.1 to 152.7 +/- 2.0 cm (p less than 0.05). Height predictions also increased without therapy during the 2-year observation period in group 2, from 165.4 +/- 3.0 to 168.7 +/- 4.1 cm (p less than 0.05). Our data indicate that gonadotropin releasing hormone agonist therapy preserves height potential in girls with an initially impaired height prognosis, and that height potential is preserved without therapy in those with a good initial height prognosis.

Luteinizing hormone-releasing hormone analogue (Buserelin) treatment for central precocious puberty: a multi-centre trial

A multi-centre open trial of Buserelin, a luteinizing hormone-releasing hormone (LHRH) analogue, was conducted in 13 children with central precocious puberty. Eleven children (eight girls and three boys), aged 3.4-10.2 years at commencement, completed the required 12 month period of treatment. Initially all patients received the drug by intranasal spray in a dose of 1200 micrograms/day, but by the end of the 12 month period two were having daily subcutaneous injections and three were receiving an increased dose intranasally. The first month of treatment was associated in one boy with increased aggression and masturbation, and in the girls with an increase in the prevalence of vaginal bleeding. Thereafter, however, both behavioural abnormalities and menstruation were suppressed. Median bone age increased significantly during the study, but without any significant change in the ratio of height age to bone age. The median predicted adult height for the group therefore did not alter significantly over the twelve months of the study. Buserelin treatment caused a reduction in the peak luteinizing hormone and follicle-stimulating hormone (FSH) responses to LHRH, mostly to prepubertal levels, and also suppressed basal FSH. In the first weeks of treatment, the girls' serum oestradiol levels rose significantly and then fell to prepubertal or early pubertal levels. A similar pattern was seen for serum testosterone levels. Serum somatomedin-C levels, however, showed little fluctuation over the course of the study. Buserelin treatment was safe and well accepted, and offers the promise of improved linear growth potential in precocious puberty.

Treatment of precocious puberty using an intranasal luteinizing hormone-releasing hormone analogue: Buserelin

Fourteen patients with precocious puberty were treated for 1-3 years with 900-1800 micrograms/day of intranasal (i.n.) Buserelin. The peak luteinizing hormone and follicle-stimulating hormone responses to intravenous luteinizing hormone-releasing hormone were reduced significantly 4 weeks after starting treatment and remained suppressed while the patients were on treatment. Two patients were withdrawn because of drug non-compliance. Three patients showed regression of pubertal changes, four patients showed no progression and five patients showed progression of breast size or pubic hair staging after 1.5-2 years of treatment. Treatment was changed to the subcutaneous route in two patients because of hormonal escape and accelerated skeletal maturation. The mean growth velocity decreased from 10.78 cm/year (s.e.m. = 0.64) to 7.06 cm/year (s.e.m. = 0.85) after 1 year of treatment (P less than 0.005). After an increase in dosage (from 900 micrograms/day to 1800 micrograms/day) in most patients, further significant falls in growth velocity to 5.29 cm/year (s.e.m. = 0.45), 4.63 cm/year (s.e.m. = 0.8) and 5.06 cm/year (s.e.m. = 0.5) were observed at 18, 24 and 30 months, respectively, compared with the pretreatment value (P less than 0.001). With treatment, the increased rate of skeletal maturation normalized. In 10 patients who had completed 2 years of treatment, the height standard deviation score for bone age improved from a pretreatment value of -2.42 +/- 0.42 to -1.6 +/- 0.42 after 2 years of treatment (P less than 0.01), indicating an improvement in height prognosis. It is concluded that i.n. Buserelin at a dose of 1800 micrograms/day is effective in the treatment of most but not all patients with precocious puberty.