Prenatal exposure to organochlorine pesticides and polychlorinated biphenyls and risk of testicular germ cell cancer later in life.

Introduction: Exposure to environmental chemicals during fetal development may increase the risk of testicular germ cell cancer (TGCC), but few studies have tested the hypothesis. We focused on organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), previously investigated in relation to other male reproductive health outcomes.

Methods: We conducted a nested case-control study of 332 mother-son pairs, comprising 65 TGCC cases and 267 controls, identified from a Danish Pregnancy Screening Registry with biobanked serum samples collected from pregnant women in 1985-1995, when exposure to the studied chemicals was relatively high. We quantified seven OCPs and 13 PCB congeners in maternal serum by gas chromatography tandem mass spectrometry. TGCC diagnoses and covariate information were derived from the nationwide Danish registries. We estimated associations between individual chemicals and their mixture with the risk of TGCC through adapted Cox regression and quantile g-computation models.

Results: Median age at TGCC diagnosis was 24.7 years. In main analyses, associations between individual OCPs and PCBs and risk of TGCC showed either slightly higher risks or no association (close to Hazard Ratios (HR) of 1.00), with confidence intervals overlapping unity. In mixture analyses, simultaneously increasing all chemical concentrations by one quartile resulted in a slightly higher risk of TGCC (HR 1.11, 95 % CI: 0.61; 2.05) after adjusting for confounders. Sensitivity analyses investigating tertiles of concentrations did not change the overall pattern of results.

Conclusions: Prenatal exposure to OCPs and PCBs, quantified by concentrations in maternal pregnancy serum, was not associated with later risk of TGCC.