Background Posterior reversible encephalopathy syndrome (PRES) is a distinct entity with incompletely known predisposing factors. The aim of this study is to describe the incidence, risk factors, clinical course, and outcome of PRES in childhood acute lymphoblastic leukemia (ALL). Procedure Patients aged 1.0 to 17.9 years diagnosed with ALL from July 2008 to December 2015 and treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol were included. Patients with PRES were identified in the prospective NOPHO leukemia toxicity registry, and clinical data were collected from the medical records. Results The study group included 1378 patients, of whom 52 met the criteria for PRES. The cumulative incidence of PRES at one month was 1.7% (95% CI, 1.1–2.5) and at one year 3.7% (95% CI, 2.9–4.9). Older age (hazard ratios [HR] for each one‐year increase in age 1.1; 95% CI, 1.0–1.2, P = 0.001) and T‐cell immunophenotype (HR, 2.9; 95% CI, 1.6–5.3, P = 0.0005) were associated with PRES. Central nervous system (CNS) involvement (odds ratios [OR] = 2.8; 95% CI, 1.2–6.5, P = 0.015) was associated with early PRES and high‐risk block treatment (HR = 2.63; 95% CI, 1.1–6.4, P = 0.033) with late PRES. At follow‐up of the PRES patients, seven patients had epilepsy and seven had neurocognitive difficulties. Conclusion PRES is a neurotoxicity in the treatment of childhood ALL with both acute and long‐term morbidity. Older age, T‐cell leukemia, CNS involvement and high‐risk block treatment are risk factors for PRES.

The prevalence of CF is higher among Nordic survivors of AML, IA, and WT than GP controls of similar age. CF is associated with impaired HRQoL in survivors. However, they reported better mental health than CF GP controls. This might indicate different underlying mechanisms of CF in the two populations.

Cow's milk consumption in infancy is not related to IDDM in Iceland. The lower fraction of A1 and B beta-caseins in Icelandic cow's milk may explain why there is a lower incidence of IDDM in Iceland than in Scandinavia.

Norwegian long-term survivors of childhood malignant lymphomas are showing improved level of knowledge of their diagnosis and treatment modalities during the last decade. Still, independent of age at diagnosis and level of education, they are insufficiently aware of their risk of late effects.