Children with Down syndrome (DS) are highly susceptible to acute leukaemia. Given the potential role of infections in the aetiology of leukaemia in children without DS, we investigated whether there was an association between early-life infections and acute leukaemia in children with DS. Maternal infections during pregnancy were also examined. We enrolled 158 incident cases of acute leukaemia in children with DS (97 acute lymphoblastic leukaemia (ALL) and 61 acute myeloid leukaemia (AML)) diagnosed at Children's Oncology Group institutions between 1997 and 2002. DS controls (N=173) were selected from the cases' primary care clinics and frequency matched on age at leukaemia diagnosis. Data were collected on demographics, child's medical history, mother's medical history, and other factors by maternal interview. Analyses were conducted using unconditional logistic regression adjusted for potential confounders. A significant negative association was observed between acute leukaemia and any infection in the first 2 years of life (adjusted odds ratio (OR)=0.55, 95% confidence interval (CI) (0.33-0.92); OR=0.53, 95% CI (0.29-0.97); and OR=0.59, 95% CI (0.28-1.25) for acute leukaemia combined, ALL, and AML respectively). The association between acute leukaemia and maternal infections during pregnancy was in the same direction but not significant. This study offers support for the hypothesis that early-life infections may play a protective role in the aetiology of acute leukaemia in children with DS.

Data on five allergic conditions were abstracted from the medical records of 180 cases of childhood acute lymphoblastic leukaemia (ALL) and 718 matched controls. Odds Ratios (OR) and 95% Confidence Intervals (CI) were estimated for composite variables and for individual allergies using conditional logistic regression modelling. Allergies were divided into late and early diagnoses (those made within the year before the matched case's ALL diagnosis and those made earlier, respectively). Among the early diagnoses, atopy or hives was significantly associated with ALL (OR=2.20; 95% CI: 1.16-4.16). Significant associations were found for late diagnoses of atopy or hives (OR=3.78; 95% CI: 1.00-14.29) and of asthma (OR=3.10; 95% CI: 1.39-6.95). None of the other allergic conditions were associated with ALL. These results are contrary to those of prior studies of childhood ALL and allergy. © 2003 Elsevier Ltd. All rights reserved.

Several case-control studies have demonstrated positive associations between parental occupational exposures and childhood cancer. However, an overestimation of risk estimates due to recall bias is of concern. The magnitude and nature of this bias were explored using data from a German case-control study on childhood leukemia conducted between 1992 and 1997. A moderate overreporting of occupational exposures by fathers was observed, particularly for the prenatal period. Overreporting was most apparent when the time between exposure and interview was short. It was also found that job titles were no satisfactory substitute for information on specific occupational exposures. The results of this analysis emphasize the need for more sophisticated exposure assessment methods in epidemiologic studies of childhood cancer. However, because future case-control studies will at least partially rely on questionnaire data, improvements including probing questions, better interview techniques, and validation studies are indicated.

Background Familial aggregation in childhood leukemia is associated with epidemiological and genomic factors. Albeit epidemiological studies on the familial history of hematological malignancies (FHHM) 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. Methods A series of 5,878 childhood leukemia (≤21 years of age) from the EMiLI study (2000-2019) was 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 WHO recommendations. Logistic regression-derived odds ratios (OR), and 95% confidence intervals (CI) 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. Results FHC were identified in 472 of 3,618 eligible cases (13%). Ninety-six of the 472 patients (20.3%) had an occurrence of FHHM amongst relatives. FHC was significantly associated with AML (OR, 1.36, 95% CI,1.01-1.82; p=0.040). Considering only first-degree relatives, the OR was 2.92, 95% CI,1.57-5.42, and adjOR, 1.16 (1.03-1.30; p=0.012) were observed. Conclusions Our 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 Brazil's risk of developing myeloid malignancies.

Background-Prior research has focused on early outcomes after congenital heart surgery, but less is known about later risks. We aimed to determine the late causes of death among children (<21 years of age) surviving their initial congenital heart surgery.