This study investigated the impact of residential radon exposure on human cancers (i.e., lung cancer and childhood leukemia) through a systematic review and meta-analysis of case−control studies. A total of 9724 articles obtained from electronic databases were assessed; however, only 55 case−control studies were eligible after manually screening and eliminating unnecessary studies. The causal associations were addressed by determining the meta-analysis’s estimated size effects (i.e., ORs/RRs) of the meta-analysis. Residential radon was revealed to significantly increase the incidence of lung cancer and childhood leukemia with pooled ORs of 1.38 [1.19; 1.60] (I2 = 90%; p < 0.00001) and 1.43 [1.19; 1.72] (I2 = 0% and p = 0.51), respectively. In addition, subgroup analyses were performed to reduce the heterogeneity of the initial meta-analyses. The results provided strong evidence that inhaling radon in the indoor environments is closely associated with the development of lung cancer and childhood leukemia in patients living in Europe and areas with high radon levels (≥100 Bq/m3).

Myeloid sarcoma (MS), a tumor consisting of myeloid blasts with or without maturation, occurs at anatomical sites other than the bone marrow. MS of the gastrointestinal tract presenting with jaundice in children is rare. We report the case of a 4-year-old boy with a 6-week history of symptoms of obstructive jaundice due to a peripancreatic mass compressing the common bile duct. Six weeks later, blasts were found in a peripheral smear prior to surgical biopsy; bone marrow evaluation and flow cytometry results led to a diagnosis of acute myeloid leukemia (AML) with MS. No further invasive testing or temporary drainage was performed. He was started on induction therapy with full therapeutic doses of cytarabine, dose reductions of etoposide, and escalating doses of daunorubicin. His liver enzymes normalized, and he completed subsequent cycles of chemotherapy with full doses. The abdominal ultrasound showed resolution of the mass after the second cycle of chemotherapy. He is currently in remission three years after completing therapy. AML-directed chemotherapy in patients with obstructive jaundice secondary to MS may be beneficial without requiring invasive testing or temporary drainage procedures. Daily follow-up is crucial for chemotherapy dose modifications. Management plans should be individualized according to the patient\'s clinical condition.

The association between childhood leukemia and extremely low frequency magnetic fields (ELF-MF) generated by power lines and various electric appliances has been studied extensively during the past 40 years. However, the conditions under which ELF-MF represent a risk factor for leukemia are still unclear. Therefore, we have performed a systematic review and meta-analysis to clarify the relation between ELF-MF from several sources and childhood leukemia. We have systematically searched Medline, Scopus, Cochrane Database of Systematic Review and DARE to identify each article that has examined the relationship between ELF-MF and childhood leukemia. We have performed a global meta-analysis that takes into account the different measures used to assess magnetic field exposure: magnetic flux density measurements (<0.2 µT vs. >0.2 µT), distances between the child\'s home and power lines (>200 m vs. <200 m) and wire codings (low current configuration vs. high current configuration). Moreover, meta-analyses either based on magnetic flux densities, on proximity to power lines or on wire codings have been performed. The association between electric appliances and childhood leukemia has also been examined. Of the 863 references identified, 38 studies have been included in our systematic review. Our global meta-analysis indicated an association between childhood leukemia and ELF-MF (21 studies, pooled OR=1.26; 95% CI 1.06-1.49), an association mainly explained by the studies conducted before 2000 (earlier studies: pooled OR=1.51; 95% CI 1.26-1.80 vs. later studies: pooled OR=1.04; 95% CI 0.84-1.29). Our meta-analyses based only on magnetic field measurements indicated that the magnetic flux density threshold associated with childhood leukemia is higher than 0.4 µT (12 studies, >0.4 µT: pooled OR=1.37; 95% CI 1.05-1.80; acute lymphoblastic leukemia alone: seven studies, >0.4 µT: pooled OR=1.88; 95% CI 1.31-2.70). Lower magnetic fields were not associated with leukemia (12 studies, 0.1-0.2 µT: pooled OR=1.04; 95% CI 0.88-1.24; 0.2-0.4 µT: pooled OR=1.07; 95% CI 0.87-1.30). Our meta-analyses based only on distances (five studies) showed that the pooled ORs for living within 50 m and 200 m of power lines were 1.11 (95% CI 0.81-1.52) and 0.98 (95% CI 0.85-1.12), respectively. The pooled OR for living within 50 m of power lines and acute lymphoblastic leukemia analyzed separately was 1.44 (95% CI 0.72-2.88). Our meta-analyses based only on wire codings (five studies) indicated that the pooled OR for the very high current configuration (VHCC) was 1.23 (95% CI 0.72-2.10). Finally, the risk of childhood leukemia was increased after exposure to electric blankets (four studies, pooled OR=2.75; 95% CI 1.71-4.42) and, to a lesser extent, electric clocks (four studies, pooled OR=1.27; 95% CI 1.01-1.60). Our results suggest that ELF-MF higher than 0.4 µT can increase the risk of developing leukemia in children, probably acute lymphoblastic leukemia. Prolonged exposure to electric appliances that generate magnetic fields higher than 0.4 µT like electric blankets is associated with a greater risk of childhood leukemia.

Children with leukemia are at risk for epilepsy due to primary disease or neurotoxic therapies. We describe the phenotypes of drug-resistant epilepsy in 10 children with history of leukemia. Of 10 cases, 6 had features of Lennox-Gastaut syndrome, and 4 had focal epilepsy. Mean age of epilepsy onset was 5 years in Lennox-Gastaut cases and 6.5 years in focal epilepsy cases. Mean latency between leukemia diagnosis and seizure onset was about 3 years. Brain MRI of 2 patients with epileptic encephalopathy had structural abnormalities - unclear if causative for epilepsy, and 4 had no overt structural abnormalities. In focal epilepsy group, 3 had temporal lobe epilepsy and one had fronto-temporal localization. All 10 patients had received intrathecal chemotherapy; 2 also had received whole brain irradiation. Seizures were poorly controlled in the epileptic encephalopathy group. Three underwent corpus callosotomy with variable response. Two patients with temporal lobe epilepsy had temporal lobectomy with Engel 1 outcome at 2 year follow-up in both. Two phenotypes of refractory epilepsy were observed in children with previous history of leukemia, focal epilepsy and epileptic encephalopathy. Children with temporal lobe epilepsy had good response to temporal lobectomy; response to palliative surgery was variable.

A number of epidemiologic studies with a variety of exposure assessment approaches have implicated pesticides as risk factors for childhood cancers. Here we explore the association of pesticide exposure in pregnancy and early childhood with childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) utilizing land use and pesticide use data in a sophisticated GIS tool.
We identified cancer cases less than 6 years of age from the California Cancer Registry and cancer-free controls from birth certificates. Analyses were restricted to those living in rural areas and born 1998-2011, resulting in 162 cases of childhood leukemia and 9,805 controls. Possible carcinogens were selected from the Environmental Protection Agency\'s classifications and pesticide use was collected from the California Department of Pesticide Regulation\'s (CDPR) Pesticide Use Reporting (PUR) system and linked to land-use surveys. Exposures for subjects were assessed using a 4000m buffer around the geocoded residential addresses at birth. Unconditional logistic and hierarchical regression models were used to assess individual pesticide and pesticide class associations.
We observed elevated risks for ALL with exposure to any carcinogenic pesticide (adjusted Odds Ratio (aOR): 2.83, 95% CI: 1.67-4.82), diuron (Single-pesticide model, adjusted (OR): 2.38, 95% CI: 1.57-3.60), phosmet (OR: 2.10, 95% CI: 1.46-3.02), kresoxim-methyl (OR: 1.77, 95% CI: 1.14-2.75), and propanil (OR: 2.58, 95% CI: 1.44-4.63). Analyses based on chemical classes showed elevated risks for the group of 2,6-dinitroanilines (OR: 2.50, 95% CI: 1.56-3.99), anilides (OR: 2.16, 95% CI: 1.38-3.36), and ureas (OR: 2.18, 95% CI: 1.42-3.34).
Our findings suggest that in rural areas of California exposure to certain pesticides or pesticide classes during pregnancy due to residential proximity to agricultural applications may increase the risk of childhood ALL and AML. Future studies into the mechanisms of carcinogenicity of these pesticides may be beneficial.

The role of environmental and behavioral exposures on childhood leukemia etiology is poorly understood. We examined the association of maternal and paternal tobacco smoking at different time points with the risk of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) in Costa Rican children.
We conducted a population-based case-control study on childhood leukemia in Costa Rica. Cases (n ALL = 252; n AML = 40) were diagnosed between 1995 and 2000 (aged <15 years at diagnosis) and identified from the Costa Rican Cancer Registry and the National Children\'s Hospital. A total of 578 frequency-matched population controls were sampled from the National Birth Registry. Parental tobacco smoking was assessed via face-to-face interviews. We used logistic regression models to examine the association of paternal and maternal tobacco smoking before conception, during pregnancy, and after birth with childhood ALL and AML risk, adjusted for child sex, birth year, maternal/paternal age, and parental education.
Paternal smoking before conception, during pregnancy, and after birth was associated with an increased risk of childhood AML (Odds Ratio (OR): 2.51, 95% CI: 1.21-5.17; OR: 3.21, 95% CI: 1.56-6.60; and OR: 2.83, 95% CI: 1.36-5.90, respectively). Maternal smoking during pregnancy was also associated with a modest, but imprecise increase in AML risk. We observed null associations of maternal and paternal smoking with ALL in the offspring.
Our results suggest an association between parental smoking and risk of AML, but not ALL, in Costa Rican children. These findings add to the established evidence of numerous health risks associated with smoking and highlight the potential harm of smoking during sensitive windows of the development of fetus and child.

Precision medicine has uncertain potential to address population health disparities.
Case study of disparities in pediatric acute lymphoblastic leukemia (ALL).
Literature-based evaluation of ALL in African American (AA) and European American (EA) children.
AA children have a lower incidence of ALL than EA children, experience higher relapse rates, and are more likely to be diagnosed with poor prognostic indicators. Environmental risk exposures for ALL have small effect sizes; data are insufficient to determine their contribution to differences in incidence and prognosis. Differences in prevalence of gene variants associated with treatment response contribute to higher relapse rates in AA children. However, higher relapse rates were not seen in a care setting that eliminated out of pocket costs, used risk-directed therapy, and included rigorous case management.
Unequal access to effective treatment contributes to ALL disparities. Precision medicine can help to define effective treatment for diverse patient populations.

OBJECTIVE: Our research investigated the relationship between childhood leukemia and breastfeeding in the P. R. of China.
METHODS: We conducted a retrospective case-control study from March 2008 to April 2017 at the Children\'s Hospital of Zhejiang University, Zhejiang province, P. R. of China, which reviewed 958 children who had been diagnosed with leukemia in case group and 785 healthy children in control group. Data were obtained from medical records, and if the medical records were incomplete, we called mothers of children by phone to complete the data.
RESULTS: Breastfeeding reduces the risk of childhood leukemia; the effect is greater, if feeding continued for 7-9 months (p = 0.002). In addition, we suggest that some factors such as maternal age, smoking during pregnancy, abortion history, genetic factors, parents use of hair dye, and the history of using birth control pills before pregnancy can increase the risk of childhood leukemia.
CONCLUSIONS: This study indicates that promoting breastfeeding for 7-9 months may help lower the childhood leukemia incidence. Our study firstly demonstrates that breastfeeding has protective effects against childhood leukemia in the P. R. of China.
BACKGROUND: ALL: Acute lymphocytic leukemia; AML: Acute myeloid leukemia.

Little is known about the causes of childhood cancer, partly as not many children develop cancer, although childhood cancer is a leading cause of death by disease in the young. The young age of the children suggests that risk factors for childhood cancer may be present during pregnancy. Previous studies have shown that exposure to trans-fat, a type of unsaturated fat common in industrially produced foods (iTFA), has adverse health effects in adults, including the risk of developing cancer. Haematopoietic neoplasms are the most common cancer types among European children under the age of 15 years. This study will bring new knowledge as to whether trans-fat and other fatty acids may also increase the risk of developing haematopoietic neoplasms during childhood.
We will investigate if the Danish iTFA legislation ban, which radically reduced the use of iTFA in foodstuffs, influenced the risk of childhood haematopoietic neoplasms in children born either before or after the change in legislation, adjusting for relevant secular trends. Further, in a case-control study, we will examine if levels of fatty acids in dried blood spots from newborns can predict the risk of developing childhood haematopoietic neoplasms. Permission from the Danish Data Protection Agency and the Ethical Committee has been granted.
The results from this study will provide important information about fatty acids in the mother\'s diet as a contributor to development of haematopoietic neoplasms during childhood, which may result in relevant preventive action.
Not relevant.

OBJECTIVE: Studies have reported an increased risk of childhood leukemia associated with exposure to magnetic fields. We conducted a large records-based case-control study of childhood leukemia risk and exposure to magnetic fields from power lines in California.
METHODS: The study included 5,788 childhood leukemia cases (born in and diagnosed in California 1986-2008) matched to population-based controls on age and sex. We calculated magnetic fields at birth addresses using geographic information systems, aerial imagery, historical information on load and phasing, and site visits.
RESULTS: Based on unconditional logistic regression controlling for age, sex, race/ethnicity, and socioeconomic status using subjects geocoded to a basic standard of accuracy, we report a slight risk deficit in two intermediate exposure groups and a small excess risk in the highest exposure group (odds ratio of 1.50 (95% confidence interval [0.70, 3.23])). Subgroup and sensitivity analyses as well as matched analyses gave similar results. All estimates had wide confidence intervals.
CONCLUSIONS: Our large, statewide, record-based case-control study of childhood leukemia in California does not in itself provide clear evidence of risk associated with greater exposure to magnetic fields from power lines, but could be viewed as consistent with previous findings of increased risk.