The late effects of haematopoietic stem cell transplants in paediatric patients: a 25 year review

Context: A rare, large single centre study covering all long-term health outcomes of paediatric allogeneic HSCT survivors, to provide comprehensive local data, and identify gaps and future directions for improved care.

Objective: To document endocrine sequelae and other late effects of all HSCT recipients.

Design: Retrospective review.

Setting: Royal Children's Hospital Melbourne.

Patients: 384 children and adolescents received HSCT. 228 formed the study cohort; 212 were alive at commencement of data accrual.

Intervention: None.

Main outcome measures: Incidence of endocrinopathies; fertility, growth, bone and metabolic status; subsequent malignant neoplasms (SMNs).

Results: Gonadotoxicity was more common in females (p<0.001). Total body irradiation (TBI) conditioning was more toxic than chemotherapy alone. All females receiving TBI or higher cyclophosphamide equivalent doses (CED) developed premature ovarian insufficiency (POI) . In males, impaired spermatogenesis +/- testicular endocrine dysfunction was associated with increasing testicular radiation exposure. Preservation of gonadal function was associated with younger age at HSCT. Of sexually active females, 22% reported spontaneous pregnancies. Short stature was common, with growth hormone axis disruption in 30% of these. Of patients exposed to thyroid radiation 51% developed nodules, 30% malignant. Metabolic disturbances included hypertension, dyslipidemias, with both excess and underweight reported. Fragility fractures occurred in 6%; avascular necrosis in 6%. 13% developed SMNs, risk continuing to rise throughout follow-up.

Conclusions: We confirm gonadal dysfunction, multiple endocrine and metabolic abnormalities, thyroid cancer and SMNs, as common sequelae of HSCT, and identify gaps in management - particularly the need for informed fertility counselling and pretreatment fertility preservation, evaluation and management of bone health, and underline need for early lifestyle modification, long-term surveillance, and prospective planned studies aimed at reducing complication risk.