Does transitory steroid-induced central hypothyroidism in children treated for haematological malignancies warrant clinical intervention?

Introduction: Steroid-induced central hypothyroidism (CH) is a frequent but under-diagnosed hormonal disturbance in children treated for acute lymphoblastic leukaemia (ALL) and lymphoma.

Aim of the study: To determine the occurrence, frequency of symptoms, replacement therapy administration, and association of CH with glucocorticoid therapy in children treated for haematological malignancies.

Material and methods: A prospective clinical survey was conducted on 21 patients (61.9% male, mean age 9.1 years) treated in the Children's Hospital Zagreb during 2019, of whom 12 were treated for for ALL and 6 for Hodgkin lymphoma (HL), based on clinical (signs and symptoms) and laboratory data (hormonal status).

Results: Overt CH was verified in 15 (71.4%) and mild CH in 3 patients (14.2%). The most common symptoms and signs were fatigue, apathy, and electrolyte imbalance, observed in 50% of CH cases. Hormonal substitutional therapy was initiated in 44.4% of affected patients, during a mean of 2.08 months, with significant clinical improvement. Overt CH was more prevalent in patients with ALL than in those with HL (p = 0.025). Among children with ALL there was no difference in CH occurrence between the prednisone and dexamethasone groups; however, dexamethasone-induced CH was more frequently symptomatic (p = 0.03). The prednisone dosage played no role in CH incidence in patients with HL.

Conclusions: Further studies are needed to determine the real incidence of thyroid dysfunction during intensive chemotherapy treatment in children with ALL and lymphoma. Recommendations for optimal hormonal replacement therapy and a follow-up plan for paediatric oncology patients with CH are also urgently required.