SUN-061 Anthropometric and Reproductive Outcomes of Patients with Gonadotropin-Independent Precocious Puberty Due to McCune-Albright Syndrome After Treatment with Distinct Therapeutic Agents

Ovarian estrogen-secreting cysts leading to peripheral precocious puberty (PPP) are some of the major clinical manifestations of the McCune-Albright syndrome (MAS). Therapeutic options for PPP of MAS include tamoxifen, progestational agents, aromatase inhibitors (AI) and anti-androgens that aiming to block sex steroid synthesis or action. Here, we described the anthropometric and reproductive follow-up of patients with PPP of MAS treated with distinct therapeutic agents. Thirteen unrelated girls with MAS were studied. They had PPP combined with café-au-lait spots or/and fibrous dysplasia. All patients were treated with one or more of the following agents: tamoxifen, medroxyprogesterone acetate, aromatase inhibitors (anastrozole or letrozole) and anti-androgens (cyproterone), and, in cases with secondary gonadotropic axis activation, depot GnRHa was used. Patients were evaluated every three months, when height, weight, and Tanner pubertal stage were determined. Vaginal bleeding or other adverse effects were also reviewed. The chronological age (CA) at the diagnosis of PPP was 5.9 ± 2.35 (2.4 to 10.2 years). Thelarche and vaginal bleeding were the first manifestations in 76.9% and 53%, respectively. The first choice of treatment was tamoxifen in 30.7% of the patients, followed by aromatase inhibitors (23%) and medroxyprogesterone acetate in 23% of them. Tamoxifen plus medroxyprogesterone, or cyproterone, or leuprorelin were used (each one) as the first choice in 1 patient (7.6%). Eight patients (61%) presented secondary central precocious puberty and were treated with depot GnRHa. Vaginal bleeding was recurrent in 70% of patients, during treatment. Progression of breast Tanner stage during treatment occurred in 78% of the patients. The great majority (80%) of girls presented bone age (BA) advancement at the diagnosis of PPP (mean Δ BA - CA of 3.2±1.3 yr), which was normalized for chronological age in all except one patient. The mean duration of treatment was 5.8 ± 3.4 yr (ranging from 1 to 12 yr). Three patients are still under medical treatment. Hypertrichosis and uterine enlargement were the main side effects of tamoxifen in 3 and 5 patients, respectively. One patient treated with letrozole presented laboratory hyperandrogenism. Ten patients reached their adult height (149.9 ± 7.9 cm), 60% of them were below their target height. Menarche occurred at a median age of 11.8 yr (10.4 to 14 y), and all but one patient presented regular menstrual cycles. One patient spontaneously became pregnant. Despite a reasonable number of treatment options for peripheral PP in MAS, none of them showed proven effective results in stopping vaginal bleeding, reduce pubertal progression and preserving potential genetic adult height. Therefore, due to the extremely heterogeneous nature of PPP of MAS, the clinical treatment remains a challenge.