Background Prenatal exposures including parental occupational exposures have been hypothesised to play an etiological role in testicular cancer; however, epidemiological data supporting this hypothesis remain scarce. In the NORD-TEST Study, a registry-based case-control study conducted in the Nordic countries, we examined the associations between certain parental occupational exposures before childbirth and testicular germ cell tumour (TGCT) in offspring.

Methods TGCT cases diagnosed at ages 14–49 years between 1978 and 2012 in Denmark, Finland, Norway, and Sweden were identified from the cancer registries. Four controls per case were randomly selected from the central population registry and matched to cases by country and year of birth. We retrieved information on maternal and paternal occupations before childbirth from census or Pension Fund registry. Using the Nordic job-exposure matrices, occupational information was converted to exposure indices of pesticides (all four countries) and of solvents, heavy metals, or welding fumes (Finland, Norway and Sweden only). Further, information on family history of testicular cancer and personal history of genital malformations were retrieved through registry linkages. Conditional logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI).

Results The study sample comprised 9,569 cases and 32,028 controls (8,112 cases and 26,264 controls excluding Denmark). The data showed no significant associations of TGCT risk with maternal (OR = 0.83, 95% CI: 0.56–1.23) or paternal pesticide exposure (OR = 1.03, 95% CI: 0.92–1.14). We found increased TGCT risk associated with maternal exposure to aromatic hydrocarbon solvents (OR = 1.32, 95% CI: 1.06–1.65) but no linear dose-response relationship. Parental exposures to other solvents, heavy metals, or welding fumes did not significantly increase TGCT risk.

Conclusions The NORD-TEST Study provided little evidence of associations of parental occupational exposures to pesticides, solvents, heavy metals, or welding fumes to TGCT risk, with the possible exception of maternal exposure to aromatic hydrocarbon solvents.