Fulvestrant treatment of precocious puberty in girls with McCune-Albright syndrome

[Early manifestation and progressive multicomponent current of McCune-Albright-Braitsev syndrome in a girl 9 years old: a clinical case and literature review]

McCune-Albright-Braitsev Syndrome (MAB syndrome) is a very rare multisystem disease manifested by fibrous bone dysplasia, coffee-and-milk colored spots, hyperfunction of various endocrine glands and a number of pathologies of other body systems. We present a description of a clinical case of a severe progressive course of MAB Syndrome in a nine-year-old girl. With this diagnosis, the girl is observation of the girl began when she was 2.5 years old, when spots of coffee-and-milk, polyosseous fibrous dysplasia, peripheral premature sexual development against a backdrop of estrogen--secreting ovarian cysts, multinodular goiter were detected. In the process of dynamic observation, it was noted that the child's active growth stopped against a backdrop of deformities of the skeletal system with multiple repeated fractures of the extremities; progression of skull deformity with stenosis of the optic nerve canals and deterioration of visual acuity; development of STH hypersecretion, hypophosphatemic rickets, tachycardia. Appropriate suppressive / replacement therapy was prescribed for each of the endocrine dysfunctions. The article presents algorithms for examining a girl in dynamics, criteria for choosing a component-wise management tactics and a discussion of the features of the course of all manifestations of the Syndrome.

[Clinical guidelines «Precocious puberty»]

The precocious puberty is an urgent problem of pediatric endocrinology characterized by clinical and pathogenetic heterogeneity. The appearance of secondary sex characteristics before the age of 8 years in girls and 9 years in boys requires timely diagnosis and the appointment of pathogenetically justified treatment in order to achieve the target indicators of final growth and prevent social deprivation. The developed clinical guidelines are the main working tool of the practitioner. They briefly and structurally present the main information about the epidemiology and modern classification of рrecocious puberty, methods of its diagnosis and treatment based on the principles of evidence-based medicine.

Precocious puberty

Precocious puberty (PP) is a common reason for referral to pediatric endocrinology clinics, with a strong female predominance. PP is a broad term encompassing benign variants of normal development, gonadotropin-dependent precious puberty (GDPP), and gonadotropin-independent precocious puberty (GIPP). This article reviews the definitions, physiology, clinical presentation, evaluation and treatment of these conditions.

Fibrous Dysplasia/McCune-Albright Syndrome: A Rare, Mosaic Disease of Gα s Activation

Fibrous dysplasia/McCune-Albright syndrome (FD/MAS) is a rare disorder of striking complexity. It arises from somatic, gain-of-function mutations in GNAS, leading to mosaic Gα s activation and inappropriate production of intracellular cyclic adenosine monophosphate (cAMP). The clinical phenotype is largely determined by the location and extent of affected tissues, and the pathophysiological effects of Gα s activation within these tissues. In bone, Gα s activation results in impaired differentiation of skeletal stem cells, leading to discrete skeletal lesions prone to fracture, deformity, and pain. Extraskeletal manifestations include a variable combination of hyperpigmented macules and hyperfunctioning endocrinopathies. Distinctive age-related changes in disease development has key effects on histologic, radiographic, and clinical features. FD/MAS thus presents along a uniquely broad clinical spectrum, and the resulting challenges in diagnosis and management can be difficult for clinicians. This review presents FD/MAS in the context of a mosaic disorder of Gα s activation, providing an intellectual framework within which to understand, evaluate, and treat this interesting disease. It includes a comprehensive summary of current understanding of FD/MAS pathogenesis, and a detailed discussion of clinical presentation and management. Critical areas of unmet need are highlighted, including discussion of key challenges and potential solutions to advance research and clinical care in FD/MAS.

Disorders of Puberty: Pharmacotherapeutic Strategies for Management

During puberty, with activation of the hypothalamic pituitary axis that has been quiescent since the neonatal period, linear growth accelerates, secondary sexual characteristics develop, and adult fertility potential and bone mass are achieved, together with psychosocial and emotional maturation.Disordered pubertal onset and progress, either early or late, presents frequently for endocrine care. Where a disorder is found, due either to a central hypothalamic pituitary cause or to primary gonadal failure, pharmacotherapeutic interventions are required to alter the trajectory of disturbed pubertal onset or progress and for maintenance of adolescent and adult sex hormone status. This paper describes pharmacologic interventions used for pubertal disorders but is not intended to address the diagnostic cascade in detail.

Treatment of Girls and Boys with McCune-Albright Syndrome with Precocious Puberty - Update 2017

The most common endocrinopathy associated with McCune-Albright Syndrome (MAS) is peripheral precocious puberty (PP) which occurs far more often in girls than in boys. We will discuss the latest advancements in the treatment of precocious puberty in MAS that have been achieved during the past 10 years. However, due to the rarity of the condition and the heterogeneity of the disease, research in this field is limited particularly in regards to treatment in boys. In girls, a period of watchful waiting is recommended prior to initiating therapy due to extreme variability in the clinical course. This article will review in detail current pharmacologic treatment in girls, which typically consists of either inhibiting estrogen production or blocking estrogen action at the level of the end-organ. The two treatments with the most evidence at this time are Tamoxifen (which is an estrogen receptor modulator) and Letrozole (which is a 3rd generation aromatase inhibitor). This article will also review the current treatment strategies in boys which typically include using an androgen receptor blocker and an aromatase inhibitor. Due to the rarity of the condition, large multicenter collaborative studies are needed to further investigate efficacy and safety with the goal of establishing the gold standard for treatment of PP in children with MAS.

Peripheral precocious puberty including congenital adrenal hyperplasia: causes, consequences, management and outcomes

Peripheral precocious puberty results from peripheral production of sex steroids independent of activation of the hypothalamic-pituitary gonadal axis. It is much less common than central precocious puberty. Causes are variable and can be congenital or acquired. In this review, we will discuss the diagnosis and management of the most common etiologies including congenital adrenal hyperplasia, McCune Albright syndrome, familial male-limited precocious puberty, and adrenal and gonadal tumors.

The Clinical Spectrum of McCune-Albright Syndrome and Its Management

McCune-Albright syndrome (MAS) is a rare, mosaic disorder presenting along a broad clinical spectrum. Disease arises from somatic-activating GNAS mutations, leading to constitutive Gαs activation and ligand-independent signaling of the Gαs-coupled protein receptor. The phenotype is largely determined by location and extent of tissues in which the GNAS mutation is expressed, as well as the pathophysiologic effects of Gαs activation within these tissues. Patients pre-sent clinically with a variable combination of fibrous dysplasia of bone (FD), café-au-lait skin macules, and hyperfunctioning endocrinopathies. In bone, Gαs leads to impaired differentiation of skeletal stem cells and formation of discrete, expansile FD lesions, resulting in fractures, pain, and functional impairment. A systematic approach to diagnosis and management is critically important to optimize outcomes for patients with FD/MAS. There are no medical therapies capable of altering the disease course in FD; however, screening and treatment for endocrinopathies can mitigate some skeletal morbidities. This review summarizes current understanding of MAS pathophysiology, describes the spectrum of clinical features, and includes a detailed discussion of the recommended approach to diagnosis and management.

Management of precocious puberty in girls with McCune-Albright syndrome using letrozole

Objective To evaluate the safety and efficacy of letrozole in girls with progressive precocious puberty (PP) associated with McCune-Albright syndrome (MAS). Design Monocentric retrospective cross-sectional and longitudinal study of consecutive patients. Patients Ten MAS patients treated at Peking Union Medical College Hospital between September 1999 and December 2017 were retrospectively reviewed; those with complications due to PP were followed. Results The mean age at letrozole initiation was 4.5 ± 2.6 years, while the mean duration of treatment was 3.3 ± 2.4 years. Letrozole was highly effective at decreasing the rate of skeletal maturation, with a significant decrease in the bone age-to-chronological age (BA/CA) ratio from 1.9 ± 1.1 pre-treatment to 1.5 ± 1.2 on letrozole treatment (P = 0.016). Moreover, growth velocity Z-scores declined from 0.41 ± 0.5 to -0.2 ± 0.31 with treatment (P < 0.001). Predicted adult height Z-scores increased significantly from -2.03 ± 2.33 at baseline to 1.13 ± 0.84 following treatment initiation (P = 0.029). Moreover, vaginal bleeding declined significantly on letrozole. Conclusions Our findings suggest that letrozole may be an effective therapy in some girls with MAS, as treatment results in improved BA/CA ratio, growth velocity and predicted adult height. Possible adverse effects include nettle rash.

Peculiarities of Precocious Puberty in Boys and Girls With McCune-Albright Syndrome

McCune-Albright Syndrome (MAS; OMIM # 174800) is a rare, sporadic disease caused by a post-zygotic, activating mutation in the guanine-nucleotide binding protein α-subunit (GNAS1) gene. MAS is characterized by the clinical triad of polyostotic fibrous dysplasia of bone, café-au-lait skin pigmentation and peripheral precocious puberty. However, clinical presentation is highly variable depending on mosaic tissue distribution of mutant-bearing cells. Precocious puberty is the most common endocrine manifestation of MAS and is often the presenting, and sometimes the only, clinical sign of MAS. Due to the very low prevalence of MAS, data on course of precocious puberty, effectiveness of treatments and gonadal function during post-pubertal period are lacking. Our knowledge on this issue derives essentially from case reports and small cohorts of patients. The aim of this review is to report all available literature data on clinical aspects, therapeutic management and outcomes of precocious puberty in children with MAS. A systematic research was carried out through MEDLINE via PubMed, EMBASE, Web of Science, Semantic Scholar, Cochrane Library.

Long-term outcomes of letrozole treatment for precocious puberty in girls with McCune-Albright syndrome

OBJECTIVE

McCune-Albright syndrome (MAS) is a rare disorder with a broad spectrum including precocious puberty (PP) due to recurrent estrogen-secreting ovarian cysts. This study evaluates the long-term safety and efficacy of letrozole treatment in large cohort of girls with MAS-associated PP.

DESIGN

Retrospective cohort analysis.

METHODS

Clinical data, including history and physical examination, bone age, and pelvic ultrasounds, were reviewed on 28 letrozole-treated girls. Adult height was reviewed for 42 historical controls. Outcomes included rate of skeletal maturation, growth velocity, predicted adult height and adult height.

RESULTS

Twenty-eight girls received letrozole treatment. Treatment duration was 4.1 ± 2.6 years (mean ± 1 s.d.) (range: 0.5-10.9) and mean follow-up was 6.0 ± 3.3 years (range: 0.5-15.0), for a total of 135.9 person-years of follow-up. Letrozole treatment was highly effective at decreasing the rate of skeletal maturation, with a decline in change in bone age over change in chronological age (ΔBA/ΔCA) from 1.7 (IQR: 2.3) to 0.5 (IQR: 0.4) (P < 0.0001), and growth velocity Z-scores, which declined from 2.2 ± 2.3 to -0.6 ± 1.6 (P = 0.0004). Predicted adult height Z-scores increased significantly from -2.9 ± 3.2 to -0.8 ± 1.5 for subjects on treatment (P = 0.004). Four subjects who completed treatment reached adult height Z-scores ranging from -1.5 to 1.7 (median: -0.6), which were increased in comparison with untreated historical controls (P = 0.02). There was no change in uterine size or ovarian volumes, and no adverse events over the treatment period.

CONCLUSIONS

In this study with the longest follow-up to date, letrozole treatment resulted in sustained beneficial effects on skeletal maturation, growth velocity and predicted adult height.

Etiology and therapeutic outcomes of children with gonadotropin-independent precocious puberty

PURPOSE

This study was performed to investigate the etiology, clinical features, and outcomes of patients with gonadotropin-independent precocious puberty (GIPP).

METHODS

The study included 16 patients (14 female and 2 male patients) who manifested secondary sexual characteristics, elevated sex hormones, or adrenal androgens with prepubertal luteinizing hormone levels after gonadotropin releasing hormone stimulation diagnosed between May 1994 and December 2015. Patients with congenital adrenal hyperplasia were excluded. Clinical features, laboratory findings, treatment modalities, and outcomes were retrospectively reviewed.

RESULTS

The median age at diagnosis was 2.6 years (range, 0.7-7.9 years) and median follow-up duration was 4.6 years (range, 1 month-9.8 years). Patients with McCune-Albright syndrome (n=5) and functional ovarian cysts (n=4) presented with vaginal bleeding and elevated estradiol levels (23.3±17.5 pg/mL); adrenocortical tumors (n=4) with premature pubarche and elevated dehydroepiandrosterone sulfate levels (87.2-6,530 µg/dL); and human chorionic gonadotropin (hCG)-producing tumor (n=1) with premature pubarche and elevated β-human chorionic gonadotropin levels (47.4 mIU/mL). Two patients were idiopathic. Six patients transited to gonadotropin-dependent precocious puberty median 3.3 years (range, 0.3-5.1 years) after the onset of GIPP. Initial and follow-up height standard deviation scores (0.99±0.84 vs. 1.10±1.10, P=0.44) and bone age advancement (1.49±1.77 years vs. 2.02±1.95 years, P=0.06) were not significantly different.

CONCLUSION

The etiologies of GIPP are heterogeneous, and treatment and prognosis is quite different according to the etiology. Efficacy of treatment with aromatase inhibitors needs to be evaluated after long-term follow-up.

Clinical and endocrine characteristics and genetic analysis of Korean children with McCune-Albright syndrome: a retrospective cohort study

Background

McCune–Albright syndrome (MAS) is a rare disease defined by the triad of fibrous dysplasia (FD), café au lait spots, and peripheral precocious puberty (PP). Because of the rarity of this disease, only a few individuals with MAS have been reported in Korea. We describe the various clinical and endocrine manifestations and genetic analysis of 14 patients with MAS in Korea.

Methods

Patients’ clinical data—including peripheral PP, FD, and other endocrine problems—were reviewed retrospectively. In addition, treatment experiences of letrozole in five patients with peripheral PP were described. Mutant enrichment with 3′-modified oligonucleotides - polymerase chain reaction (MEMO-PCR) was performed on eight patients to detect mutation in GNAS using blood. MEMO-PCR is a simple and practical method that enables the nondestructive selection and enrichment of minor mutant alleles in blood.

Results

The median age at diagnosis was 5 years 2 months (range: 18 months to 16 years). Eleven patients were female, and three were male. Thirteen patients showed FD. All female patients showed peripheral PP at onset, and three patients subsequently developed central PP. There was a significant decrease in estradiol levels after two years of letrozole treatment. However, bone age was advanced in four patients. Two patients had clinical hyperthyroidism, and two patients had growth hormone (GH) excess with pituitary microadenoma. c.602G > A (p.Arg201His) in GNAS was detected in two patients in blood, and c.601C > T (p.Arg201Cys) in GNAS was detected in one patient in pituitary adenoma.

Conclusions

This study described the various clinical manifestations of 14 patients with MAS in a single center in Korea. This study first applied MEMO-PCR on MAS patients to detect GNAS mutation. Because a broad spectrum of endocrine manifestations could be found in MAS, multiple endocrinopathies should be monitored in MAS patients. Better treatment options for peripheral PP with MAS are needed.

Tamoxifen Improves Final Height Prediction in Girls with McCune-Albright Syndrome: A Long Follow-Up

BACKGROUND

McCune-Albright syndrome (MAS) is a genetic disorder characterized by the triad of fibrous dysplasia, skin hyperpigmentation, and autonomous hyperfunction of various endocrine organs. MAS frequently presents in females as precocious puberty (PP). Although many treatments have been proposed, the preservation of final height (FH) in these patients remains a challenge.

OBJECTIVES

To evaluate the efficacy of tamoxifen in improving the FH prediction (FHP) in patients with MAS.

METHOD

We retrospectively analyzed 8 female patients with MAS who presented with café-au-lait spots and gonadotropin-independent PP. The patients were followed for a mean period of 8.3 years (range: 3-16).

RESULTS

All patients were treated with tamoxifen (10-20 mg/day) for 3-8 years (mean ± SD: 5.75 ± 2.05), which resulted in the cessation of vaginal bleeding and the stabilization of bone age maturation. There was a significant difference between the FHP at the beginning of treatment and at the end of treatment (145.1 ± 8.6 cm; Z score -2.84 ± 1.44 cm) and at the last evaluation (157.0 ± 9.2 cm; Z score -0.85 ± 0.54 cm; p < 0.001).

CONCLUSION

Our results support a role for tamoxifen in improving the FHP in patients with MAS.

Treatment of Peripheral Precocious Puberty

There are many etiologies of peripheral precocious puberty (PPP) with diverse manifestations resulting from exposure to androgens, estrogens, or both. The clinical presentation depends on the underlying process and may be acute or gradual. The primary goals of therapy are to halt pubertal development and restore sex steroids to prepubertal values. Attenuation of linear growth velocity and rate of skeletal maturation in order to maximize height potential are additional considerations for many patients. McCune-Albright syndrome (MAS) and familial male-limited precocious puberty (FMPP) represent rare causes of PPP that arise from activating mutations in GNAS1 and the LH receptor gene, respectively. Several different therapeutic approaches have been investigated for both conditions with variable success. Experience to date suggests that the ideal therapy for precocious puberty secondary to MAS in girls remains elusive. In contrast, while the number of treated patients remains small, several successful therapeutic options for FMPP are available.

Treatment and outcomes of precocious puberty: an update

Precocious puberty is a common problem affecting up to 29 per 100,000 girls per year. The earliest identified neuroendocrine change in early puberty thus far is increased kisspeptin secretion from the arcuate nucleus and the anteroventral paraventricular nucleus of the hypothalamus. The regulation of kisspeptin secretion is not well understood, but neurokinin B and dynorphin provide autocrine regulation. The etiologies of precocious puberty may be subdivided into GnRH-dependent and GnRH-independent causes. GnRH-dependent precocious puberty, often called central precocious puberty (CPP), is usually treated with GnRH analogs. Newer developments in the treatment of CPP include expanded data on the safety and efficacy of the subdermal histrelin implant, which is useful for long-term treatment, although removal may be difficult in some cases. Preliminary data suggest that the implant may be left in place for up to 2 years without loss of biochemical suppression. In the last 2 years, more data have been published concerning extended-release leuprolide acetate injections that indicate that the 11.25-mg dose may not provide full biochemical suppression but may clinically suppress signs of puberty, including the accelerated growth velocity and advanced skeletal maturation seen in CPP. Treatment options for familial male-limited precocious puberty and McCune-Albright syndrome are expanding as well, although data are preliminary. Long-term outcome studies of CPP indicate overall good menstrual and reproductive function, but the prevalence of polycystic ovary syndrome may be higher than in the general population. Remarkably few studies have evaluated the behavioral and psychological outcomes of precocious puberty, in contrast to early normal maturation. Additional outcome studies of endocrine, metabolic, and psychological effects of CPP are clearly needed.