Childhood cancer mortality and survival in immigrants: A population-based registry study in Finland

Maternal serum concentrations of per- and polyfluoroalkyl substances and childhood acute lymphoblastic leukemia

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are widespread and environmentally persistent chemicals with immunotoxic properties. Children are prenatally exposed through maternal transfer of PFAS to cord blood, but no studies have investigated the relationship with childhood leukemia.

METHODS

We measured maternal serum levels of 19 PFAS in first-trimester samples collected in 1986-2010 and evaluated associations with acute lymphoblastic leukemia in full-term offspring (aged younger than 15 years) for 400 cases and 400 controls in the Finnish Maternity Cohort, matched on sample year, mother's age, gestational age, birth order, and child's sex. We analyzed continuous and categorical exposures, estimating odds ratios (ORs) and 95% confidence intervals (CIs) via conditional logistic regression adjusted for maternal smoking and correlated PFAS (ρ ≥ ±0.3). We also stratified by calendar period, mean diagnosis age, and the child's sex.

RESULTS

N-methyl-perfluorooctane sulfonamidoacetic acid was associated with acute lymphoblastic leukemia in continuous models (per each doubling in levels: ORperlog2 = 1.22, 95% CI = 1.07 to 1.39), with a positive exposure-response across categories (OR>90th percentile = 2.52, 95% CI = 1.33 to 4.78; Ptrend = .01). Although we found no relationship with perfluorooctane sulfonic acid overall, an association was observed in samples collected in 1986-1995, when levels were highest (median = 17.9 µg/L; ORperlog2 = 4.01, 95% CI = 1.62 to 9.93). A positive association with perfluorononanoic acid was suggested among first births (Pinteraction = .06). The N-methyl-perfluorooctane sulfonamidoacetic acid association was mainly limited to children diagnosed before age 5 years (Pinteraction = .02). We found no consistent patterns of association with other PFAS or differences by sex.

CONCLUSIONS

These novel data offer evidence of a relationship between some PFAS and risk of the most common childhood cancer worldwide, including associations with the highest levels of perfluorooctanesulfonic acid and with a precursor, N-methyl-perfluorooctane sulfonamidoacetic acid.

Variation in disease in children according to immigrant background

BACKGROUND

A growing proportion of children born in Europe are born to immigrant parents. Knowledge about their health is essential for preventive and curative medicine and health services planning.

OBJECTIVE

To investigate differences in diagnoses given in secondary and tertiary healthcare between Norwegian-born children to immigrant and non-immigrant parents.

METHODS

Data from the Medical Birth Registry of Norway, the Norwegian Patient Registry and Statistics Norway were linked by the national personal identification number. The study population included children born in Norway aged 0-10 years between 2008 and 2018 (N=1,015,267). Diagnostic categories from three main domains of physical health, given in secondary or tertiary care; infections, non-infectious medical conditions and non-infectious neurological conditions were included from 2008 onwards. Hazards of diagnoses by immigrant background were assessed by Cox regressions adjusted for sex and birth year.

RESULTS

Children of immigrants generally had higher hazards than children with Norwegian background of some types of infections, obesity, nutrition-related disorders, skin diseases, blood disease and genital disease. Children of immigrants from Africa also had higher hazards of cerebral palsy, cerebrovascular diseases and epilepsy. Conversely, most groups of children of immigrants had lower hazards of acute lower respiratory tract infections, infections of the musculoskeletal system, infections of the central nervous system, diseases of the circulatory system, hearing impairment, immune system disorders, chronic lower respiratory disease and headache conditions.

CONCLUSIONS

Children of immigrants did not present with overall worse health than children without immigrant background, but the distribution of health problems varied between groups.