Parental occupation and childhood germ cell tumors: a case\u2013control study in Denmark, 1968\u20132016

Clinton Hall,Ondine S Von Ehrenstein,Di He,Julia E Heck,Jørn Olsen,Beate Ritz,Johnni Hansen

doi:10.1007/s10552-021-01434-0

Abstract

PurposeTo examine associations between parental occupation and childhood germ cell tumors (GCTs) in offspring while distinguishing by common histologic subtype (i.e., yolk sac tumor and teratoma).MethodsThis population-based case–control study included childhood GCT cases in Denmark diagnosed 1968–2015 (< 16 years old at diagnosis) and sex and birth year-matched controls. Demographic information and parental employment histories were obtained from Danish registries. Parental occupation was assessed by industry; job-exposure matrices were used to examine specific occupational exposures (i.e., potentially carcinogenic organic solvents and social contact). Conditional multivariable logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CIs).ResultsOverall, 178 childhood GCT cases (50 yolk sac tumors; 65 teratomas) and 4,355 controls were included for analysis. Maternal employment in education during pregnancy was associated with offspring GCTs (OR 2.45, 95% CI 1.23–4.90), especially yolk sac tumors (OR 5.27, 95% CI 1.94–14.28). High levels of both maternal and paternal occupational social contact were also associated with offspring yolk sac tumors across all exposure periods (ORs 2.30–4.63). No signals were observed for paternal occupational solvent exposure, while imprecise associations were estimated for maternal exposure (e.g., dichloromethane exposure during pregnancy, OR 1.51, 95% CI 0.77–2.95).ConclusionOur findings suggest that parental occupation is associated with offspring GCTs, with most consistent evidence supporting an association between maternal employment in education or other high social contact jobs and offspring yolk sac tumors.

Highlights

Childhood germ cell tumors (GCTs) are a rare group of heterogenous neoplasms with largely unknown etiology [1]
Maternal employment in education and job-exposure matrices (JEMs) classification as high/very high social contact were moderately correlated; and the associations we observed with these exposures suggest infectious and immunologic risk factors for childhood GCTs
One prior study including 451 GCT cases < 6 years identified an imprecise association with maternal Group B streptococcus infection during pregnancy [3], while another study of 105 malignant GCT cases < 15 years found a strong association with maternal urinary infection during pregnancy, but not with any viral infection [6]; neither study showed results by histologic subtype

Summary

Introduction

Childhood germ cell tumors (GCTs) are a rare group of heterogenous neoplasms with largely unknown etiology [1]. In Europe, the incidence rate of GCTs among children ages 0–14 is estimated to be 4.8 per million [2]. The two most common GCT subtypes are yolk sac tumors and teratomas; evidence suggests these cancers have different risk profiles [1, 3], but few observational studies have provided subtype-specific results. Despite the rarity of epidemiologic studies on childhood GCTs, consistent associations have been observed with Asian/Pacific Islander racial identification, birth defects, and abnormal fetal growth [3, 4]; the latter suggest that prenatal exposures are associated with childhood GCT development. While parental occupational exposures have been examined for several childhood cancers, there are few studies for childhood GCTs. Previously, we observed an association between

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Conclusion