Endocrine Abstracts

Introduction: Children undergoing treatment for cancer are prone to several long-term endocrine complications, which can permanently affect bone tissue.

Case report: A 25-year-old man was diagnosed with right maxillary sinus rhabdomyosarcoma at the age of 5. He was submitted to chemotherapy – intrathecal methotrexate+prednisolone and i.v. vincristine+actinomycin+ifosfamide – and submaxillary+cervical radiotherapy, 60Gy. At the age of 12, he was referenced to Endocrine Rehabilitation Clinics. Laboratory: IGF1 102 ng/ml (<p3), TSH 7.4 mIU/ml (0.3–4.2), T₃ 120 ng/dl (80–200), FT₄ 0.8 ng/dl (0.9–1.7). He started levothyroxine (50 μg/day). Adrenal and gonadal axes were normal. Insulin-tolerance-test showed GH insufficiency. Auxology: height 139 cm (p10), predicted adult stature (PAS) 170 cm; bone age 9 years; Tanner stages P2G2, testicular volume (TV) 5 ml. According to national criteria back then, he wasn’t eligible for somatropin treatment. Pubertal spurt wasn’t achieved. At the age of 14 growth velocity remained in p3 (−2SD). He reached P5G5, TV 25 ml when he was 17. PAS wasn’t achieved. One year later he performed bone mineral density (BMD) scan – T-score: lumbar spine (LS) −3.1, femoral neck (FN) −1.9. Calcium and cholecalciferol were started, without improvement. At the age of 21 he showed: LH 1.7 mIU/ml (>8), FSH 2.0 mIU/ml (>10), total testosterone 324.8 ng/dl (160–730) and dihydrotestosterone 253 ng/dl (300–850). Testosterone enanthate 250 mg/ml monthly was started. Despite correct replacement and appropriate physical activity, 2 years later he presented with T-score: −3.8 (LS), −2.1 (FN). He was still showing IGF1 of 79 ng/ml (<p3) so he started somatropin. Currently (25-year-old) he exhibits T - score: −3.6 (LS), −2.3 (FN).

Conclusion: Our patient developed growth hormone insufficiency secondary to radiotherapy. This contributed to impaired bone mass acquisition. Methotrexate and glucocorticoids’ adverse effects on bone are usually reversible. Peak bone mass should already been reached when partial gonadal axis insufficiency was established. It’s important to identify the risk of endocrine complications in order to treat these patients properly.