Summary Our group recently showed that the (ASNase) formulation available in Brazil from 2017 to 2018 when used at the same dose and frequency as the formulation provided previously did not reach the activity considered therapeutic. Based on these, our goal was to assess the impact of these facts on the prognosis of children with ALL at different oncology centers. A multicentre retrospective observational study followed by a prospective follow‐up. Patients aged >1 and <18 years in first‐line treatment followed up at 10 referral centres, between 2014 and 2018 who received the formulation Leuginase® were identified (Group B). For each patient, the centre registered 2 patients who received ASNase in the presentation of Aginasa® exclusively (Group A). Data collection was registered using (Redcap®). A total of 419 patients were included; 282 in Group A and 137 in B. Group A had a 3‐year OS and EFS of 91·8% and 84·8% respectively, while Group B had a 3‐year OS of 83·8% (P = 0·003) and EFS of 76·1% (P = 0·008). There was an impact on 3‐year OS and EFS of children who received a formulation. This result highlights the importance of evaluating ASNase and monitoring its activity.

BackgroundFamilial aggregation in childhood leukemia is associated with epidemiological and genomic factors. Albeit epidemiological studies on the familial history of hematological malignancies (FHHMs) are scarce, genome-wide studies have identified inherited gene variants associated with leukemia risk. We revisited a dataset of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) patients to explore the familial aggregation of malignancies among their relatives.MethodsA series of 5,878 childhood leukemia (≤21 years of age) from the EMiLI study (2000–2019) were assessed. Lack of well-documented familial history of cancer (FHC) and 670 cases associated with genetic phenotypic syndromes were excluded. Leukemia subtypes were established according to World Health Organization recommendations. Logistic regression-derived odds ratios (ORs) and 95% confidence intervals (CIs) were performed and adjusted by age as a continuous variable, where ALL was the reference group for AML and conversely. The pedigree of 18 families with excess hematological malignancy was constructed.ResultsFHC was identified in 472 of 3,618 eligible cases (13%). Ninety-six of the 472 patients (20.3%) had an occurrence of FHHMs among relatives. Overall, FHC was significantly associated with AML (OR, 1.36; 95% CI, 1.01–1.82; p = 0.040). Regarding the first-degree relatives, the OR, 2.92 95% CI,1.57-5.42 and the adjOR, 1.16 (1.03-1.30; p0.001) were found for FHC and FHHM, respectively.ConclusionOur findings confirmed that AML subtypes presented a significant association with hematological malignancies in first-degree relatives. Genomic studies are needed to identify germline mutations that significantly increase the risk of developing myeloid malignancies in Brazil.