Tamoxifen improved final height prediction in a girl with McCune-Albright syndrome: patient report and literature review

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.

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.

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.

Contemporary issues in precocious puberty

Precocious puberty poses significant diagnostic and therapeutic challenge to the physician. Recent advances in the understanding of pathophysiology of precocious puberty have resulted in improved management. Timely intervention is mandatory to achieve successful outcome. The identification of critical role of KISS-1-kisspeptin-GPR54 system has gone a long way to provide an insight into pubertal physiology. It is likely that the system would become an important diagnostic and therapeutic target in children with precocious puberty. Epidemiological studies point toward earlier thelarche. This is, however, associated with slower progression as the age of menarche is static. These changes have led to suggestions of lowering the age cutoffs for precocious puberty in girls. New developments in assessment of precocious puberty including gonadotropin releasing hormone (GnRH) agonist test have made characterization of precocious puberty easier. Longstanding GnRH analogs have become the mainstay of treatment of gonadotropin-dependent precocious puberty, while aromatase inhibitors and inhibitors of sex hormone action are increasingly being used in gonadotropin-independent precocious puberty.

Tamoxifen treatment in a patient with blepharophimosis-ptosis-epicanthus inversus syndrome and peripheral precocious puberty

Patients with blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) can be classified as types 1 or 2, according to the presence or not of ovarian failure. We report a 5 year-old girl with BPES and large multicystic ovaries who developed peripheral precocious puberty with thelarche (Tanner stage III) and pubarche (Tanner stage II). Pelvic ultrasound revealed pubertal uterus and enlarged multicystic ovaries. Fibrous dysplasia and McCune-Albright syndrome were ruled out. Treatment with an estrogen antagonist was started (tamoxifen, 10 mg/day), achieving regression of thelarche. Tamoxifen treatment was stopped at 10-(7/12) years, and growth velocity and skeletal maturation rate returned to normal. No treatment-associated adverse effects were observed.