Incidence and severity of crucial late effects after allogeneic HSCT for ă malignancy under the age of 3 years: TBI is what really matters

Younger children are considered to be more vulnerable to late effects ă (LE), which prompted us to study LE in patients after haematopoietic ă stem cell transplantation (HSCT) for a haematological malignancy before ă the age of 3. In this multicentre EBMT study, cumulative incidence (CI) ă and severity of endocrine LE, central nervous system complications and ă secondary malignancies at 5, 10, 15 and 20 years of follow-up were ă assessed. Risk factors (RF) like gender, diagnosis, age at and year of ă HSCT, TBI-or chemo-conditioning and GVHD were analysed. CI of any LE was ă 0.30, 0.52, 0.66 and 0.72 at 5, 10, 15 and 20 years after HSCT, ă respectively. In 25% of the patients, LE were severe at a median ă follow-up of 10.4 years. In multivariate analysis, only TBI was a RF for ă having any LE and for thyroid dysfunction and growth disturbance. Female ă gender was a RF for delayed pubertal development. Some more insight ă could be gained by descriptive analysis regarding the role of TBI and ă GVHD on the severity of LE. Although only five selected LE have been ă studied and median follow-up is relatively short, the incidence and ă severity of these LE are considerable but not different from what has ă been found in older children and TBI is the main RF.