Tamoxifen treatment for precocious puberty in McCune-Albright syndrome: a multicenter trial

Practical solutions for including sex as a biological variable (SABV) in preclinical neuropsychopharmacological research

Recently, many funding agencies have released guidelines on the importance of considering sex as a biological variable (SABV) as an experimental factor, aiming to address sex differences and avoid possible sex biases to enhance the reproducibility and translational relevance of preclinical research. In neuroscience and pharmacology, the female sex is often omitted from experimental designs, with researchers generalizing male-driven outcomes to both sexes, risking a biased or limited understanding of disease mechanisms and thus potentially ineffective therapeutics. Herein, we describe key methodological aspects that should be considered when sex is factored into in vitro and in vivo experiments and provide practical knowledge for researchers to incorporate SABV into preclinical research. Both age and sex significantly influence biological and behavioral processes due to critical changes at different timepoints of development for males and females and due to hormonal fluctuations across the rodent lifespan. We show that including both sexes does not require larger sample sizes, and even if sex is included as an independent variable in the study design, a moderate increase in sample size is sufficient. Moreover, the importance of tracking hormone levels in both sexes and the differentiation between sex differences and sex-related strategy in behaviors are explained. Finally, the lack of robust data on how biological sex influences the pharmacokinetic (PK), pharmacodynamic (PD), or toxicological effects of various preclinically administered drugs to animals due to the exclusion of female animals is discussed, and methodological strategies to enhance the rigor and translational relevance of preclinical research are proposed.

[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.

Diagnosis and management of precocious sexual maturation: an updated review

The classic definition of precocious sexual maturation is the development of secondary sexual characteristics before 8 years of age in girls and before 9 years of age in boys. It is classified as central precocious puberty when premature maturation of the hypothalamic-pituitary-gonadal axis occurs, and as peripheral precocious puberty when there is excessive secretion of sex hormones, independent of gonadotropin secretion. Precocious sexual maturation is more common in girls, generally central precocious puberty of idiopathic origin. In boys, it tends to be linked to central nervous system abnormalities. Clinical evaluation should include a detailed history and physical examination, including anthropometric measurements, calculation of growth velocity, and evaluation of secondary sexual characteristics. The main sign to suspect the onset of puberty is breast tissue development (thelarche) in girls and testicular enlargement (≥4 mL) in boys. Hormonal assessment and imaging are required for diagnosis and identification of the etiology. Genetic testing should be considered if there is a family history of precocious puberty or other clinical features suggestive of a genetic syndrome. Long-acting gonadotropin-releasing hormone analogs are the standard of care for central precocious puberty management, while peripheral precocious puberty management depends on the etiology.Conclusion: The aim of this review is to address the epidemiology, etiology, clinical assessment, and management of precocious sexual maturation. What is Known: • The main sign to suspect the onset of puberty is breast tissue development (thelarche) in girls and testicular enlargement (≥4 mL) in boys. The classic definition of precocious sexual maturation is the development of secondary sexual characteristics before 8 years of age in girls and before 9 years of age in boys. • Long-acting gonadotropin-releasing hormone agonist (GnRHa) is the standard of care for CPP management, and adequate hormone suppression results in the stabilization of pubertal progression, a decline in growth velocity, and a decrease in bone age advancement. What is New: • Most cases of precocious sexual maturation are gonadotropin-dependent and currently assumed to be idiopathic, but mutations in genes involved in pubertal development have been identified, such as MKRN3 and DLK1. • A different preparation of long-acting GnRHa is now available: 6-month subcutaneous injection.

[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.

Prescribing Tamoxifen in Patients With Mood Disorders: A Systematic Review of Potential Antimanic Versus Depressive Effects

PURPOSE/BACKGROUND

Tamoxifen is a selective estrogen receptor modulator widely used for treatment and prevention of estrogenic receptor-positive breast cancer. Tamoxifen is an object of growing interest in psychopharmacology as an antimanic drug, because it inhibits the protein kinase C, a molecular target of bipolar disorder. Consistently, the potential depressive effect of tamoxifen has been repeatedly reported.

METHODS/PROCEDURES

This article systematically reviews studies examining tamoxifen impact on mood, exploring either its potential therapeutic use as antimanic agent or its potential depressive effect.

FINDINGS

Eight studies explored tamoxifen antimanic properties, all, but one, reported a rapid and efficacious antimanic action. As to the depressive effect, 9 cohort studies emerged among which 4 pointed out an increased risk of depression. Seven case reports described the onset or exacerbation of depressive episodes besides 1 case series study reported a high rate of depressive symptoms. In addition, 1 case report study described a tamoxifen-induced manic episode.

IMPLICATIONS/CONCLUSIONS

The present review highlights tamoxifen treatment as a possible trigger of mood symptoms onset or exacerbation in vulnerable patients. Accordingly, patients with a history of mood disorders may require a close clinical surveillance during tamoxifen use. At the same time, the use of tamoxifen as an antimanic agent in psychiatric settings requires caution, as available evidence came from small-sample studies with short observation time. More studies are needed to define how long-term tamoxifen use may affect the course of bipolar disorder.

Fertility in McCune Albright syndrome female: A case study focusing on AMH as a marker of ovarian dysfunction and a literature review

BACKGROUND

The molecular basis of McCune Albright syndrome (MAS) is a recurrent GNAS Postzygotic gain of function sporadic mutation, resulting in a mosaic disease. Most of girls present precocious puberty, caused by the development of recurrent ovarian cysts with autonomous Hyperestrogenic stimulation. After menarche, the majority of patients with ovarian GNAS mutation have menstrual disturbances and infertility.

OBJECTIVES

We wanted to focus on the fertility of MAS females and propose an appropriate management, by a detailed case report and an exhaustive review of the literature on fertility and pregnancy in MAS females.

RESULTS

We present the case of a 29-year-old MAS female, who had previously undergone a unilateral ovariectomy and was managed by in vitro fertilization (IVF). Eight oocytes with many morphological abnormalities were retrieved. The GNAS mutation was found at a low frequency in follicular cells. The ovarian histopathological examination showed developing follicles of all stages, strongly expressing AMH by immunohistochemistry. In addition, AMH was high (45.5 pmol/L) and the AMH / AFC ratio (5.69 pmol/L per follicle) was much higher than in PCOS and control groups (2.16, and 1.34 respectively).

CONCLUSIONS

Ovarian and endometrial involvement can be responsible for infertility in MAS women. IVF and oophorectomy may be useful in management. The genetic characterization of the different tissues may have a prognostic utility. Moreover, we suggest that the AMH could be a marker of the ovarian activity in MAS. Further studies are needed to clarify the potential oocyte abnormalities and the risk of miscarriages in order to guide genetic counseling.

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.

Update on Precocious Puberty in Girls

Precocious puberty (PP) in girls refers to secondary sexual development occurring earlier than the lower end of normal for the onset of puberty. It might be the presenting feature of a serious underlying condition or signify a common variation of normal for which no treatment is necessary. Depending on the source and type of sex steroids involved, clinical findings may indicate exposure to estrogens, androgens, or both. Likewise, the onset of the PP might be gradual or abrupt and the rate of progression is variable. Recent years have witnessed exciting advancements in the understanding of the molecular genetic basis for some forms of PP in girls as well as in the development of additional treatment options. In this review an update on the most commonly encountered causes of PP in girls including their clinical presentation, pathophysiology, diagnosis, and management are provided. Recommendations regarding when to refer, and areas in particular need of additional research are also delineated.

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.

Fibrous Dysplasia of Bone and McCune-Albright Syndrome: A Bench to Bedside Review

Fibrous dysplasia is an uncommon mosaic disorder in which bone is replaced by structurally unsound fibro-osseous tissue. It is caused by the sporadic post-zygotic activating mutations in GNAS, resulting in dysregulated Gα_S-protein signaling in affected tissues. This manifests on a broad clinical spectrum ranging from insignificant solitary lesions to severe disease with deformities, fractures, functional impairment, and pain. Fibrous dysplasia may present in isolation or in association with hyperfunctioning endocrinopathies and café-au-lait macules, known as McCune-Albright Syndrome. This review summarizes the current understanding of pathophysiology in fibrous dysplasia, describes key pre-clinical and clinical investigations, and details the current approach to diagnosis and management.

Off-label use of tamoxifen in a Chinese tertiary care hospital

Background Tamoxifen is an estrogen receptor modulator used for the treatment of breast cancer; however, currently, it is used in many off-label indications. Objective To investigate the prevalence of tamoxifen off-label prescribing and explore available scientific evidence that supports those uses in outpatients. Setting Xiamen maternity and child health care hospital in Xiamen city of China. Method All the prescriptions of outpatients receiving tamoxifen were exported from an electronic prescribing system during a 1-year period. Tamoxifen use was then classified as either on- or off-label according to the criteria we established previously, and the details of the off-label prescriptions were collected. Logistic regression was applied to explore predictive variables. Evidence search was limited to Up-To-Date, the Micromedex database and PubMed. Main outcome measure The rate of off-label use, risk factors identified by logistic regression and evidence exhibition. Results A total of 75% of all the prescriptions available were classified as off-label use. Hyperplasia of the breast was the most frequently prescribed off-label indication. According to the analysis of logistic regression, male patients, patients less than 34 years old, and physicians with a higher professional title were more likely associated with off-label prescribing. After a search in Up-To-Date, the Micromedex database and PubMed, only male infertility, atypical hyperplasia, mastodynia, peripheral precocious puberty and gynecomastia were found to have strong evidence supporting the use of tamoxifen off-label (22.75%). Conclusion Although the off-label use of tamoxifen was common in our hospital, there was a relative shortage of evidence available supporting those uses.

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.

Tamoxifen prolongs survival and alleviates symptoms in mice with fatal X-linked myotubular myopathy

X-linked myotubular myopathy (XLMTM, also known as XLCNM) is a severe congenital muscular disorder due to mutations in the myotubularin gene, MTM1. It is characterized by generalized hypotonia, leading to neonatal death of most patients. No specific treatment exists. Here, we show that tamoxifen, a well-known drug used against breast cancer, rescues the phenotype of Mtm1-deficient mice. Tamoxifen increases lifespan several-fold while improving overall motor function and preventing disease progression including lower limb paralysis. Tamoxifen corrects functional, histological and molecular hallmarks of XLMTM, with improved force output, myonuclei positioning, myofibrillar structure, triad number, and excitation-contraction coupling. Tamoxifen normalizes the expression level of the XLMTM disease modifiers DNM2 and PI3KC2B, likely contributing to the phenotypic rescue. Our findings demonstrate that tamoxifen is a promising candidate for clinical evaluation in XLMTM patients.

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.

Induction and Maintenance of Amenorrhea in Transmasculine and Nonbinary Adolescents

The treatment of persistent uterine bleeding in those patients who identify as transmasculine or nonbinary is often straightforward, but can be difficult in a subset of patients. This article reviews the physiology of the normal menstrual cycle and the hormonal influences on the endometrium, and then explores options for the treatment of persistent bleeding for people both already on testosterone and for those who are either not ready for or who do not desire testosterone.

Orthognathic surgery during breast cancer treatment-A case report

INTRODUCTION

In recent years, patients with orthognathic surgery in middle-aged and elderly people have come to be a more frequent occurrence. Breast cancer is the most frequently diagnosed cancer in woman worldwide, and its prevalence rate is steadily increasing.

PRESENTATION OF CASE

We report a case of a 47-year-old Japanese woman in whom left-side breast cancer (Stage 1) was unexpectedly found just before orthognathic surgery in April 2012. Breast-conserving surgery was performed (estrogen receptor+, progesterone receptor+, HER2 -, surgical margin+, sentinel lymph node +) that May. From June to August docetaxel (75mg/m2) and cyclophosphamide (600mg/m2) were administrated four times every 21days and thereafter radiotherapy (total 60Gy) was completed. The cancer surgeon declared the prognosis good and the patient had a strong desire to undergo orthognathic surgery, so in November we performed a bimaxillary osteotomy, and administration of tamoxifen began 6 weeks after the osteotomy.

DISCUSSION

There are breast cancer cases in which the prognosis is sufficiently good for a planned orthognathic surgery to proceed. Good communication among surgeons and the patient is important.

CONCLUSION

We experienced a case in which breast cancer was found just before the orthognathic surgery; we performed a bimaxillary osteotomy, including follow-up tamoxifen administration, during breast cancer treatment.

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.

Pharmacological therapeutics targeting the secondary defects and downstream pathology of Duchenne muscular dystrophy

INTRODUCTION

Since the identification of the dystrophin gene in 1986, a cure for Duchenne muscular dystrophy (DMD) has yet to be discovered. Presently, there are a number of genetic-based therapies in development aimed at restoration and/or repair of the primary defect. However, growing understanding of the pathophysiological consequences of dystrophin absence has revealed several promising downstream targets for the development of therapeutics.

AREAS COVERED

In this review, we discuss various strategies for DMD therapy targeting downstream consequences of dystrophin absence including loss of muscle mass, inflammation, fibrosis, calcium overload, oxidative stress, and ischemia. The rationale of each approach and the efficacy of drugs in preclinical and clinical studies are discussed.

EXPERT OPINION

For the last 30 years, effective DMD drug therapy has been limited to corticosteroids, which are associated with a number of negative side effects. Our knowledge of the consequences of dystrophin absence that contribute to DMD pathology has revealed several potential therapeutic targets. Some of these approaches may have potential to improve or slow disease progression independently or in combination with genetic-based approaches. The applicability of these pharmacological therapies to DMD patients irrespective of their genetic mutation, as well as the potential benefits even for advanced stage patients warrants their continued investigation.

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.

Medication Repurposing in Pediatric Patients: Teaching Old Drugs New Tricks

OBJECTIVES

Gaps in pediatric therapeutics often result in off-label use and specifically, novel uses for existing medications, termed "drug repurposing." Drug Information (DI) queries to a Pediatric Medication Resource Center of a large metropolitan pediatric hospital in New York and inherent difficulties in retrieving evidence-based information prompted a review of current medication repurposing for pediatric patients. The objective included characterization of innovative off-label use of medications Food and Drug Administration (FDA)-approved for 1 or more indications to treat a totally different disorder or indication in pediatric patients.

METHODS

A systematic literature review was conducted to retrieve publications describing repurposed medications in pediatric patients. Excluded was FDA-approved indications used off-label in pediatric patients (e.g., different dose), preclinical data, adult use only, and experimental use. Evidence quality was classified using a modified American Academy of Neurology Level of Evidence. Results were analyzed using χ(2) at p < 0.05.

RESULTS

Over 2000 references were retrieved and reviewed. A total of 101 medications repurposed for novel off-label uses for pediatric patients were identified: 38 for neonates, 74 for children, and 52 for adolescents. Neonates and infants were least likely to receive a medication for a repurposed use. Strong or intermediate evidence existed in 80.2% of cases. The evidence was weak in 19.8%. No significant relationship was observed between the pediatric age group and strength of the literature. Most repurposed uses pertained to generic or widely used medications. Less than 5% of medications were first marketed after 2011.

CONCLUSIONS

While not exhaustive, the present study represents the most comprehensive listing of novel uses exclusive to pediatric patients. Further research is needed to identify the frequency of repurposed uses. The valuable DI role of pharmacists in assessing repurposed uses is of expanding and increasing importance to ensure such uses are evidence-based.

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.

Autonomous Ovarian Cysts in Prepubertal Girls. How Aggressive Should We Be? A Review of the Literature

STUDY OBJECTIVE

Precocious pseudopuberty in girls occurs as a result of peripheral estrogen production, most commonly through an autonomous ovarian cyst or in patients with McCune Albright syndrome. Current management is either conservative or surgical. The aim of this study was to identify available literature on presentation, course and treatment of such cases.

DESIGN

We performed a medline literature search using the key words 'ovarian autonomous cyst' and 'pseudopuberty'. We included articles published in English, from 1980 to date relating to females aged 2 to 8 years. We excluded papers on other endocrine conditions resulting in premature puberty.

OUTCOME MEASURES

Type of management, time of resolution, recurrence, progression to Central Precocious Puberty and McCune Albright Syndrome.

RESULTS

We identified 9 articles referring to 26 cases of autonomous ovarian cysts. All patients had suppressed LHRH testing and had simple ovarian cysts producing estradiol. Median age of patients was 5 years (range 2.2-8) and size of cyst was 41.5mm (9-60). Ten patients underwent cystectomy or oophorectomy, three were given cyproterone acetate and 13 were managed conservatively. Nine of 13 patients that were managed conservatively and two of those that had a cystectomy had a recurrence. There were three cases that progressed to central precocious puberty (CPP) and one case that was then identified to have McCune Albright (MCA) syndrome. One further case with multiple recurrences was given long term treatment with letrozole.

CONCLUSION

We conclude that although a conservative approach should always be proposed in the first instance, one should be aware of the risk of recurrence and progression to CPP or MCA. Antiestrogen treatment appears promising; however data comparing it with surgical options and particularly long term consequences with regards to future reproductive outcomes are not available.

Novel approaches to short stature therapy

Besides growth hormone, several pharmaceutical products have been investigated for efficacy and safety in increasing short term growth or adult height. Short-term treatment with testosterone esters in boys with constitutional delay of growth and puberty is efficacious in generating secondary sex characteristics and growth acceleration. The addition of oxandrolone to growth hormone (GH) in Turner syndrome has an additive effect on adult height gain. Treatment with GnRH analogs is the established treatment of central precocious puberty, and its addition to GH therapy appears effective in increasing adult height in GH deficient children, and possibly short children born SGA or with SHOX deficiency, who are still short at pubertal onset. Aromatase inhibitors appear effective in several rare disorders, but their value in increasing adult height in early pubertal boys with GH deficiency or idiopathic short stature is uncertain. A trial with a C-natriuretic peptide analog offers hope for children with achondroplasia.

Antiarrhythmic effect of tamoxifen on the vulnerability induced by hyperthyroidism to heart ischemia/reperfusion damage

Hyperthyroidism, known to have deleterious effects on heart function, and is associated with an enhanced metabolic state, implying an increased production of reactive oxygen species. Tamoxifen is a selective antagonist of estrogen receptors. These receptors make the hyperthyroid heart more susceptible to ischemia/reperfusion. Tamoxifen is also well-known as an antioxidant. The aim of the present study was to explore the possible protective effect of tamoxifen on heart function in hyperthyroid rats. Rats were injected daily with 3,5,3'-triiodothyronine at 2mg/kg body weight during 5 days to induce hyperthyroidism. One group was treated with 10mg/kg tamoxifen and another was not. The protective effect of the drug on heart rhythm was analyzed after 5 min of coronary occlusion followed by 5 min reperfusion. In hyperthyroid rats not treated with tamoxifen, ECG tracings showed post-reperfusion arrhythmias, and heart mitochondria isolated from the ventricular free wall lost the ability to accumulate and retain matrix Ca(2+) and to form a high electric gradient. Both of these adverse effects were avoided with tamoxifen treatment. Hyperthyroidism-induced oxidative stress caused inhibition of cis-aconitase and disruption of mitochondrial DNA, effects which were also avoided by tamoxifen treatment. The current results support the idea that tamoxifen inhibits the hypersensitivity of hyperthyroid rat myocardium to reperfusion damage, probably because its antioxidant activity inhibits the mitochondrial permeability transition.

Three intragenic suppressors of a GTPase-deficient allele of GNAS associated with McCune-Albright syndrome

Gain-of-function mutations in heterotrimeric G-protein α subunits are associated with a variety of human diseases. McCune-Albright syndrome (MAS) is caused by mutations in GNAS, the gene encoding Gs. Alterations at Arg201 significantly reduce the GTPase activity of the protein, rendering it constitutively active. In this study, we have constructed a library of random mutations in a constitutively active yeast GPA1 gene carrying a mutation homologous to the McCune-Albright allele (Arg297His). Intragenic suppressors found at sites with homology to the human Gs protein were tested for their ability to suppress the constitutive activity of an Arg201His mutation in Gs. Three intragenic suppressors, at Phe142, Arg231, and Leu266, were able to suppress elevated basal cAMP responses caused by Arg201His when expressed in HEK293 cells. A range of amino acid substitutions was introduced at each of these sites to investigate the chemical requirements for intragenic suppression. The ability of Gs proteins carrying the suppressor mutations alone to mediate receptor-induced cAMP production was measured. These results offer potential sites on Gs that could serve as drug targets for MAS therapies.

The anticancer drug tamoxifen counteracts the pathology in a mouse model of duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a severe disorder characterized by progressive muscle wasting,respiratory and cardiac impairments, and premature death. No treatment exists so far, and the identification of active substances to fight DMD is urgently needed. We found that tamoxifen, a drug used to treat estrogen-dependent breast cancer, caused remarkable improvements of muscle force and of diaphragm and cardiac structure in the mdx(5Cv) mouse model of DMD. Oral tamoxifen treatment from 3 weeks of age for 15 months at a dose of 10 mg/kg/day stabilized myofiber membranes, normalized whole body force, and increased force production and resistance to repeated contractions of the triceps muscle above normal values. Tamoxifen improved the structure of leg muscles and diminished cardiac fibrosis by~ 50%. Tamoxifen also reduced fibrosis in the diaphragm, while increasing its thickness,myofiber count, and myofiber diameter, thereby augmenting by 72% the amount of contractile tissue available for respiratory function. Tamoxifen conferred a markedly slower phenotype to the muscles.Tamoxifen and its metabolites were present in nanomolar concentrations in plasma and muscles,suggesting signaling through high-affinity targets. Interestingly, the estrogen receptors ERa and ERb were several times more abundant in dystrophic than in normal muscles, and tamoxifen normalized the relative abundance of ERb isoforms. Our findings suggest that tamoxifen might be a useful therapy for DMD.

Intragenic suppression of a constitutively active allele of Gsα associated with McCune-Albright syndrome

McCune-Albright syndrome (MAS) is a human genetic disorder caused by a mutation that constitutively activates the G(s)α subunit by abolishing GTP hydrolysis. MAS patients suffer from a range of endocrinopathies as well as polyostotic fibrous dysplasia of bone. We previously identified an intragenic suppressor of the MAS mutation in a yeast system, which substituted two residues in the GTP-binding site of Gpa1: L318P and D319V to suppress the constitutive activity of an R297H mutation, corresponding to the human F222P, D223V, and R201H mutations respectively. To extend these studies, the human GNAS gene was subjected to site-directed mutagenesis. Constructs expressing the MAS mutation (R201H), the MAS mutation plus the mutations homologous to the yeast suppressors (R201H, F222P/D223V), or the yeast suppressor mutation alone (F222P/D223V) were transfected into HEK293 cells, and basal and receptor-stimulated cAMP levels were measured. Expression of R201H increased the basal cAMP levels and decreased the EC(50) for hormone-stimulated cAMP production. These effects were dependent on the amount of R201H protein expressed. R201H, F222P/D223V abolished the constitutive activity of the MAS mutation and caused responses to hormone that were not different from those measured in cells expressing WT G(s)α. Interestingly, F222P/D223V behaved similar to R201H in causing increases in basal cAMP production, thus demonstrating constitutive activity. Substitution of another acidic (E) or polar (N, T, and G) amino acid at position 223 caused no suppression of R201H activity, while substitution of a second nonpolar amino acid (A) at this position partially suppressed, and the larger polar I residue completely suppressed the effects of R201H.

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

Background

McCune-Albright Syndrome (MAS) is usually characterized by the triad of precocious puberty (PP), fibrous dysplasia, and café au lait spots. Previous treatments investigated for PP have included aromatase inhibitors and the estrogen receptor modulator, tamoxifen. Although some agents have been partially effective, the optimal pharmacologic treatment of PP in girls with MAS has not been identified. The objective of this study was to evaluate the safety and efficacy of fulvestrant (Faslodex^TM), a pure estrogen receptor antagonist, in girls with progressive precocious puberty (PP) associated with McCune-Albright Syndrome (MAS).

Methods

In this prospective international multicenter trial, thirty girls ≤ 10 years old with MAS and progressive PP received fulvestrant 4 mg/kg via monthly intramuscular injections for 12 months. Changes in vaginal bleeding, rates of bone age advancement, growth velocity, Tanner staging, predicted adult heights, and uterine and ovarian volumes were measured.

Results

Median vaginal bleeding days decreased from 12.0 days per year to 1.0 day per year, with a median change in frequency of -3.6 days, (95% confidence interval (CI) -10.10, 0.00; p = 0.0146). Of patients with baseline bleeding, 74% experienced a ≥50% reduction in bleeding, and 35% experienced complete cessation during the study period (95% CI 51.6%, 89.8%; 16.4%, 57.3%, respectively). Average rates of bone age advancement (ΔBA/ΔCA) decreased from 1.99 pre-treatment to 1.06 on treatment (mean change -0.93, 95% CI -1.43, -0.43; p = 0.0007). No significant changes in uterine volumes or other endpoints or serious adverse events occurred.

Conclusions

Fulvestrant was well tolerated and moderately effective in decreasing vaginal bleeding and rates of skeletal maturation in girls with MAS. Longer-term studies aimed at further defining potential benefits and risks of this novel therapeutic approach in girls with MAS are needed.

Trial registration

NCT00278915

Characterization and management of testicular pathology in McCune-Albright syndrome

CONTEXT

The testicular phenotype in McCune-Albright syndrome (MAS) has not been well characterized. Boys present with a relatively low incidence of precocious puberty in comparison with girls. Radiographic and histological studies are limited to small series and case reports, which report testicular microlithiasis and Sertoli cell hyperplasia.

OBJECTIVE

Our objective was to characterize the biochemical, radiological, and histological spectrum and clinical management of testicular pathology in males with MAS.

PATIENTS, DESIGN, AND SETTING

Fifty-four males with MAS participated in this prospective cohort study at a clinical research center.

INTERVENTION

Evaluation included testicular exam, pubertal staging, testicular ultrasound, measurement of LH, FSH, and testosterone. Orchiectomies were performed when considered clinically indicated.

MAIN OUTCOME MEASURE

Prevalence and characterization of ultrasound lesions with correlation to histology were evaluated.

RESULTS

Of 54 males, 44 (81%) presented with ultrasound abnormalities including hyperechoic lesions (49%), hypoechoic lesions (30%), microlithiasis (30%), heterogeneity (47%), and focal calcifications (11%). Eight subjects underwent orchiectomy revealing large foci of Leydig cell hyperplasia, which could not be definitively distinguished from Leydig cell tumor. After no subjects developed clinical malignancy, a conservative approach was instituted, and subsequent subjects were followed with serial imaging. Testosterone and gonadotropins were normal in subjects without precocious puberty or pituitary disease. Eleven (21%) presented with precocious puberty, and a combination of aromatase inhibitors, androgen receptor blockers, and leuprolide resulted in improved predicted adult height. In addition, the first cases of testicular adrenal rest and bilateral germ cell tumors in association with MAS are presented.

CONCLUSIONS

Contrary to prevailing thinking, the incidence of gonadal pathology in MAS is equal in males and females. The predominant histopathological finding was Leydig cell hyperplasia, which carries a low risk of malignant transformation and can be managed conservatively.

Fetal ovarian cysts: an early manifestation of McCune-Albright syndrome?

OBJECTIVE

Beyond the classic triad of peripheral precocious puberty, café-au-lait skin pigmentation and polyostotic fibrous dysplasia, partial presentation McCune-Albright syndrome (MAS) has been reported, including the association of isolated recurrent ovarian cysts in early infancy. The aims of this study were to determine whether isolated voluminous fetal unilateral ovarian cysts (diameter > 4 cm) may be associated with a Gsα activating mutation, suggestive of MAS.

DESIGN

We followed five female fetuses presenting with voluminous unilateral ovarian cysts by ultrasonography until delivery. At birth, all patients underwent percutaneous cyst aspiration and two patients later underwent ovariectomy. A sensitive PCR-based method was used to analyze the Gsα activating mutation in DNA obtained from ovarian cystic fluids or tissue.

RESULTS

Among the five cases, one Gsα mutation (R201C) was identified in the ovarian tissue.

CONCLUSIONS

We demonstrate for the first time that voluminous fetal unilateral ovarian cysts may be suggestive of MAS. Systematic search for the Gsα mutation should be performed in all newborns with voluminous fetal unilateral ovarian cysts requiring percutaneous cyst aspiration, because early diagnosis of MAS prevents unnecessary oophorectomy to eliminate questions of malignancy and imposes long-term clinical, biological, and imaging follow-up to detect other early manifestations of MAS.

Diagnosis and management of precocious puberty in atypical presentations of McCune-Albright syndrome: a case series review

BACKGROUND

McCune-Albright syndrome is a rare syndrome, classically defined as the triad of precocious puberty, fibrous dysplasia of bone, and café au lait lesions. Partial or atypical presentations of McCune-Albright syndrome, with only one or two of the classic symptoms, have been described in the literature and remain particularly challenging due to lack of diagnostic phenotype. In these patients, the utility of analysis of mutations in the gene of the α subunit of the stimulatory G-protein is limited and so the diagnosis is often based on clinical judgment. Three atypical cases of suspected McCune-Albright syndrome with gonadotropin-independent precocious puberty are presented.

CASES

Case #1: A 5-year-old female presented with painlesss vaginal bleeding and was found to have café au lait lesions. She was diagnosed with gonadotropin independent precocious puberty with eventual progression to gonadotropin dependent precocious puberty which was successfully treated with both letrozole and gonadotropin-releasing hormone agonist therapy. Case #2: A 3-year-old female presented with painless vaginal bleeding and was found to have café au lait lesions. She was diagnosed with gonadotropin independent precocious puberty and was successfully treated with letrozole. Case #3: A 5-year-old female presented with fibrous dysplasia and was found to have evidence of uterine and ovarian enlargement on ultrasound. She was diagnosed with gonadotropin-independent precocious puberty and was successfully treated with letrozole.

SUMMARY AND CONCLUSION

Although different in presentation, all three atypical cases of suspected McCune-Albright syndrome with gonadotropin-independent precocious puberty were successfully treated with aromatase inhibitors. This small case series shows the utility and efficacy of aromatase inhibitors in the setting of atypical cases of suspected MAS with gonadotropin-independent precocious puberty.

Strategies for maximizing growth in puberty in children with short stature

The approach to the child with growth retardation who is in puberty remains an important clinical challenge. The use of high-dose growth hormone (GH), suppression of puberty with GnRH analogs in combination with GH, and the use of selective inhibitors of the aromatase enzyme with aromatase inhibitors (also in combination with GH) are all therapeutic choices that have been studied. Aromatase blockade effectively blocks estrogen production in males with a reciprocal increase in testosterone, and a new generation of aromatase inhibitors, including anastrozole, letrozole and exemestane, is under investigation in adolescent subjects with severe growth retardation. This class of drugs, if judiciously used for a window of time, offers promise as an adjunct treatment of growth delay in pubertal patients with GH deficiency, idiopathic short stature, testotoxicosis, and other disorders of growth. These evolving uses of aromatase inhibitors, however, represent off-label use of the product, and definitive data on their efficacy are not available for each of the conditions mentioned. Safety issues regarding bone health also require further study.

Genetic regulation of the growth plate

The epiphyseal growth plate consists of a layer of cartilage present only during the growth period and vanishes soon after puberty in long bones. It is divided to three well-defined zones, from epiphyses; resting, proliferative, and hypertrophic zones. Chondrocyte proliferation and differentiation and subsequent bone formation in this cartilage are controlled by various endocrine, autocrine, and paracrine factors which finally results into elimination of the cartilaginous tissue and promotion of the epiphyseal fusion. As chondrocytes differentiate from round, quiescent, and single structure to flatten and proliferative and then large and terminally differentiated, they experience changes in their gene expression pattern which allow them to transform from cartilaginous tissue to bone. This review summarizes the literature in this area and shortly describes different factors that affect growth plate cartilage both at the local and systemic levels. This may eventually help us to develop new treatment strategies of different growth disorders.

Strategies for maximizing growth in puberty in children with short stature

The approach to the child with growth retardation who is in puberty remains an important clinical challenge. The use of high-dose growth hormone (GH), suppression of puberty with GnRH analogs in combination with GH, and the use of selective inhibitors of the aromatase enzyme with aromatase inhibitors (also in combination with GH) are all therapeutic choices that have been studied. Aromatase blockade effectively blocks estrogen production in males with a reciprocal increase in testosterone, and a new generation of aromatase inhibitors, including anastrozole, letrozole and exemestane, is under investigation in adolescent subjects with severe growth retardation. This class of drugs, if judiciously used for a window of time, offers promise as an adjunct treatment of growth delay in pubertal patients with GH deficiency, idiopathic short stature, testotoxicosis, and other disorders of growth. These evolving uses of aromatase inhibitors, however, represent off-label use of the product, and definitive data on their efficacy are not available for each of the conditions mentioned. Safety issues regarding bone health also require further study.

Update on the etiology, diagnosis and therapeutic management of sexual precocity

Precocious puberty is defined as the development of secondary sexual characteristics before the age of 8 years in girls and 9 years in boys. Gonadotropin-dependent precocious puberty (GDPP) results from the premature activation of the hypothalamic-pituitary-gonadal axis and mimics the physiological pubertal development, although at an inadequate chronological age. Hormonal evaluation, mainly through basal and GnRH-stimulated LH levels shows activation of the gonadotropic axis. Gonadotropin-independent precocious puberty (GIPP) is the result of the secretion of sex steroids, independently from the activation of the gonadotropic axis. Several genetic causes, including constitutive activating mutations in the human LH-receptor gene and activating mutations in the Gs protein a-subunit gene are described as the etiology of testotoxicosis and McCune-Albright syndrome, respectively. The differential diagnosis between GDPP and GIPP has direct implications on the therapeutic option. Long-acting gonadotropin-releasing hormone (GnRH) analogs are the treatment of choice in GDPP. The treatment monitoring is carried out by clinical examination, hormonal evaluation measurements and image studies. For treatment of GIPP, drugs that act by blocking the action of sex steroids on their specific receptors (cyproterone, tamoxifen) or through their synthesis (ketoconazole, medroxyprogesterone, aromatase inhibitors) are used. In addition, variants of the normal pubertal development include isolated forms of precocious thelarche, precocious pubarche and precocious menarche. Here, we provide an update on the etiology, diagnosis and management of sexual precocity.

Tamoxifen impairs both longitudinal and cortical bone growth in young male rats

Tamoxifen (Tam) has been used experimentally to treat boys with gynecomastia and girls with McCune-Albright syndrome. This drug was recently shown to inhibit the growth of cultured fetal rat metatarsal bones and thus might also affect bone growth in vivo. Four-week-old Sprague-Dawley rats were gavaged daily with vehicle alone (peanut oil), Tam (40 mg/kg/d; 1 or 4 wk), or estradiol (40 microg/kg/d; 4 wk). Five of the 10 rats in each group were killed after 4 wk and the other five after 14 wk of recovery. Bone growth was followed by repeat DXA scans, whereas other bone parameters and spine length were evaluated by pQCT and X-ray at the time of death. Four-week Tam treatment significantly decreased body weight, nose-anus distance, spinal and tibial bone lengths, trabecular BMD, cortical periosteal circumference, and bone strength and also reduced serum IGF-I levels (424 +/- 54 versus 606 +/- 53 ng/ml in control; p < 0.05). Analysis of the tibial growth plate of treated rats showed elevated chondrocyte proliferation (BrdU) and apoptosis (TUNEL), as well as decreases in the number of hypertrophic chondrocytes and in the size of terminal hypertrophic chondrocytes. Despite a complete catch-up of body weight after 14 wk of recovery, the tibia was still shorter (p < 0.001) and its cortical region was smaller. We conclude that, when administered at a clinically relevant dose, Tam causes persistent retardation of longitudinal and cortical radial bone growth in young male rats. Our findings suggest that this inhibition results from local effects on the growth plate cartilage and systemic suppression of IGF-I production. Based on these rat data, we believe that Tam, if given to growing individuals, might compromise cortical bone growth, bone strength, and adult height.

The aromatase inhibitor anastrozole is ineffective in the treatment of precocious puberty in girls with McCune-Albright syndrome

CONTEXT

Precocious puberty (PP) in girls with McCune-Albright syndrome (MAS) is characterized by episodic development of large unilateral ovarian cysts followed by sudden onset of vaginal bleeding. Some patients experience frequent bleeding as well as accelerated linear growth and advanced skeletal maturation. The use of anastrozole for the treatment of PP in this condition has not been well studied.

OBJECTIVE

The objective of the study was to determine the safety and efficacy of the aromatase inhibitor anastrozole for the treatment of PP in girls with MAS.

DESIGN AND SETTINGS

This was a prospective international multicenter study in which subjects received anastrozole 1 mg daily for 1 yr.

PATIENTS

Twenty-eight girls 10 years of age or younger with MAS and progressive PP were enrolled.

MAIN OUTCOME MEASURES

Vaginal bleeding, rate of skeletal maturation (change in bone age over change in chronological age), growth velocity, and uterine/ovarian volumes were measured. These indices were compared with a 6-month pretreatment interval.

RESULTS

No difference in vaginal bleeding (mean number of days per year) was noted. Mean change in DeltaBA/DeltaCA, which was 1.25 +/- 0.77 at baseline, was -0.25 +/- 1.02 at study end (P = 0.22). Average growth velocity z score was 1.40 +/- 3.15 at study entry and 0.26 +/- 2.71 at 12 months (P = 0.10). Mean ovarian/uterine volumes were unaffected by anastrozole, and no significant adverse events occurred.

CONCLUSIONS

Although it appears safe, anastrozole for 1 yr was ineffective in halting vaginal bleeding, attenuating rates of skeletal maturation, and linear growth in girls with MAS. Pharmacological strategies other than anastrozole should be pursued for the treatment of PP in this population.

McCune-Albright syndrome. Orphanet J Rare Dis. 2008;3:12. [PMID: 18489744 PMCID: PMC2459161 DOI: 10.1186/1750-1172-3-12]

McCune-Albright syndrome (MAS) is classically defined by the clinical triad of fibrous dysplasia of bone (FD), café-au-lait skin spots, and precocious puberty (PP). It is a rare disease with estimated prevalence between 1/100,000 and 1/1,000,000. FD can involve a single or multiple skeletal sites and presents with a limp and/or pain, and, occasionally, a pathologic fracture. Scoliosis is common and may be progressive. In addition to PP (vaginal bleeding or spotting and development of breast tissue in girls, testicular and penile enlargement and precocious sexual behavior in boys), other hyperfunctioning endocrinopathies may be involved including hyperthyroidism, growth hormone excess, Cushing syndrome, and renal phosphate wasting. Café-au-lait spots usually appear in the neonatal period, but it is most often PP or FD that brings the child to medical attention. Renal involvement is seen in approximately 50% of the patients with MAS. The disease results from somatic mutations of the GNAS gene, specifically mutations in the cAMP regulating protein, G_s alpha. The extent of the disease is determined by the proliferation, migration and survival of the cell in which the mutation spontaneously occurs during embryonic development. Diagnosis of MAS is usually established on clinical grounds. Plain radiographs are often sufficient to make the diagnosis of FD and biopsy of FD lesions can confirm the diagnosis. The evaluation of patients with MAS should be guided by knowledge of the spectrum of tissues that may be involved, with specific testing for each. Genetic testing is possible, but is not routinely available. Genetic counseling, however, should be offered. Differential diagnoses include neurofibromatosis, osteofibrous dysplasia, non-ossifying fibromas, idiopathic central precocious puberty, and ovarian neoplasm. Treatment is dictated by the tissues affected, and the extent to which they are affected. Generally, some form of surgical intervention is recommended. Bisphosphonates are frequently used in the treatment of FD. Strengthening exercises are recommended to help maintaining the musculature around the FD bone and minimize the risk for fracture. Treatment of all endocrinopathies is required. Malignancies associated with MAS are distinctly rare occurrences. Malignant transformation of FD lesions occurs in probably less than 1% of the cases of MAS.