Posterior reversible encephalopathy syndrome in children with acute lymphoblastic leukemia: Clinical characteristics, risk factors, course, and outcome of disease.

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.

Children with low-risk acute lymphoblastic leukemia are at highest risk of second cancers.

BACKGROUND: The improved survival rates for childhood acute lymphoblastic leukemia (ALL) may be jeopardized by the development of a second cancer, which has been associated with thiopurine therapy. PROCEDURE: We retrospectively analyzed three sequential Nordic Society of Paediatric Haematology and Oncology's protocols characterized by increasing intensity of thiopurine-based maintenance therapy. We explored the risk of second cancer in relation to protocols, risk group, thiopurine methyltransferase (TPMT) activity, ALL high hyperdiploidy (HeH), and t(12;21)[ETV6/RUNX1]. RESULTS: After median 9.5 years (interquartile range, 5.4-15.3 yrs) of follow-up, 40 of 3,591 patients had developed a second cancer, of whom 38 had non-high-risk B-cell precursor ALL. Patients with standard-risk ALL, who received the longest maintenance therapy, had the highest adjusted hazard of second cancer (hazard ratio [HR], intermediate vs. standard risk: 0.16, 95% CI: 0.06-0.43, P < 0.001; HR, high vs. standard risk: 0.09, 95% CI: 0.02-0.49, P = 0.006); no significant effects of protocol, age, or white blood cell count at diagnosis, ALL HeH, or t(12;21)[ETV6/RUNX1] were observed. A subset analysis on the patients with standard-risk ALL did not show an increased hazard of second cancer from either HeH or t(12;21) (adjusted HR 2.02, 95% CI: 0.69-5.96, P = 0.20). The effect of low TPMT low activity was explored in patients reaching maintenance therapy in clinical remission (n = 3,368); no association with second cancer was observed (adjusted HR 1.43, 95% CI: 0.54-3.76, P = 0.47). CONCLUSIONS: The rate of second cancer was generally highest in patients with low-risk ALL, but we could not identify a subset at higher risk than others.

Seizures during treatment of childhood acute lymphoblastic leukemia: A population-based cohort study.

BACKGROUND: Seizures are common in children with acute lymphoblastic leukemia (ALL). As ALL survival rates are improving, the challenge to minimize treatment related side effects and late sequelae rises. Here, we studied the frequency, timing, etiology and risk factors of seizures in ALL patients. METHODS: The study included children aged 1-17.9 years at diagnosis of B-cell-precursor and T cell ALL who were treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol between 2008 and 2015. Detailed patient data were acquired from the NOPHO ALL2008 registry and by review of medical records. RESULTS: Seizures occurred in 81/1464 (5.5%) patients. The cumulative incidence of seizures at one months was 1.7% (95% CI: 1.2-2.5) and at one year 5.3% (95% CI 4.2-6.5%). Patients aged 10-17.9 years, those with T cell immunophenotype, CNS involvement, or high-risk induction with dexamethasone had higher risk for seizures in univariable analyses. Only age remained a risk factor in multivariable analyses (the cumulative incidence of seizures for patients 10-17.9 years old at one year was 9.0% (95% CI: 6.2-12.9)). Of the 81 patients with seizures, 43 had posterior reversible encephalopathy syndrome (PRES), 15 had isolated seizures, nine had sinus venous thrombosis (SVT), three had stroke-like syndrome, and 11 had other neurotoxicities. Epilepsy diagnosis was reported in totally 11 ALL survivors at last follow up. CONCLUSION: Seizures are relatively common in ALL patients and occur most often in patients with PRES, SVT, or as an isolated symptom. Older children have higher risk of seizures.

Asparaginase-Associated Pancreatitis in Acute Lymphoblastic Leukemia: Results From the NOPHO ALL2008 Treatment of Patients 1-45 Years of Age.

PURPOSE: Asparaginase-associated pancreatitis (AAP) is common in patients with acute lymphoblastic leukemia (ALL), but risk differences across age groups both in relation to first-time AAP and after asparaginase re-exposure have not been explored. PATIENTS AND METHODS: We prospectively registered AAP (n = 168) during treatment of 2,448 consecutive ALL patients aged 1.0-45.9 years diagnosed from July 2008 to October 2018 and treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol. RESULTS: Compared with patients aged 1.0-9.9 years, adjusted AAP hazard ratios (HRa) were associated with higher age with almost identical HRa (1.6; 95% CI, 1.1 to 2.3; P = .02) for adolescents (10.0-17.9 years) and adults (18.0-45.9 years). The day 280 cumulative incidences of AAP were 7.0% for children (1.0-9.9 years: 95% CI, 5.4 to 8.6), 10.1% for adolescents (10.0 to 17.9 years: 95% CI, 7.0 to 13.3), and 11.0% for adults (18.0-45.9 years: 95% CI, 7.1 to 14.9; P = .03). Adolescents had increased odds of both acute (odds ratio [OR], 5.2; 95% CI, 2.1 to 13.2; P = .0005) and persisting complications (OR, 6.7; 95% CI, 2.4 to 18.4; P = .0002) compared with children (1.0-9.9 years), whereas adults had increased odds of only persisting complications (OR, 4.1; 95% CI, 1.4 to 11.8; P = .01). Fifteen of 34 asparaginase-rechallenged patients developed a second AAP. Asparaginase was truncated in 17/21 patients with AAP who subsequently developed leukemic relapse, but neither AAP nor the asparaginase truncation was associated with increased risk of relapse. CONCLUSION: Older children and adults had similar AAP risk, whereas morbidity was most pronounced among adolescents. Asparaginase re-exposure should be considered only for patients with an anticipated high risk of leukemic relapse, because multiple studies strongly indicate that reduction of asparaginase treatment intensity increases the risk of relapse.