Risk factors for Wilms tumor. Report from the National Wilms Tumor Study.

BACKGROUND: Previous epidemiologic studies have indicated that several factors may be associated with an increased risk of Wilms tumor including paternal occupational exposures, maternal exposure during pregnancy to cigarettes, coffee or tea, oral contraceptives, hormonal pregnancy tests, hair-coloring products, maternal hypertension, vaginal infection during pregnancy, and higher birth weight of the child. The current study examines the nonoccupational risk factors using questionnaire data from a large national collaborative clinical trial. METHODS: Parents of 200 children registered with the National Wilms Tumor Study and 233 matched controls, identified using telephone random-digit dialing, completed a self-administered questionnaire about a variety of risk factors. RESULTS: As opposed to some previous studies, no association was found for mother's smoking during pregnancy (10+ cigarettes per day; odds ratio [OR] = 0.73; 95% confidence interval [CI] = 0.40-1.34), maternal consumption of coffee or tea during pregnancy (4+ cups per day; OR = 1.31; CI = 0.57-3.01), or hypertension during pregnancy (OR = 0.96; CI = 0.45-2.06). In addition, no association was found in this study for hormone exposure during pregnancy, hair dye use, vaginal infection during pregnancy, or high birth weight. A previously unreported association with a history of household insect extermination was found (OR = 2.16; CI = 1.24-3.75). CONCLUSIONS: In general, the study failed to confirm most of the previously reported maternal risk factors for Wilms tumor. Understanding the possible role of paternal exposures may be the best objective for further research on potential risk factors for Wilms tumor.