Parental heat exposure and risk of childhood brain tumor: a Children's Oncology Group study.

Medulloblastoma (MB) and primitive neuroectodermal tumor (PNET) are histologically similar brain tumors that occur mostly in children. As part of a comprehensive case-control study of MB/PNET, this study explored parental exposure to heat and electromagnetic fields as potential risk factors. Parents of 318 cases (<6 years of age at diagnosis in 1991-1997 and registered with the Children's Cancer Group) and 318 controls selected by random digit dialing were interviewed. In univariate analyses, moderately strong associations were observed for mother's sauna use close to conception (odds ratio = 3.8, 95% confidence interval (CI): 1.0, 13.7) or in the first trimester (odds ratio = 3.6, 95% CI: 0.7, 17.3) and for father's exposure in the 3 months before the pregnancy to sauna (odds ratio = 2.4, 95% CI: 1.3, 4.5), electric blanket (odds ratio = 2.0, 95% CI: 0.9, 4.3), or any heat source (for higher exposure: odds ratio = 2.5, 95% CI: 1.4, 4.6). In multivariate models, father's sauna use and father's exposure to any heat source were associated with MB/PNET in a dose-response fashion (for high exposure: odds ratio = 3.4, 95% CI: 1.2, 9.7, and odds ratio = 2.1, 95% CI: 1.1, 4.3, respectively). This new observation regarding paternal exposure to heat just prior to the index pregnancy deserves consideration in future animal and human studies of MB/PNET.