Parental exposures to pesticides and risk of Wilms' tumor in Brazil.

Wilms' tumor is one of the most common abdominal childhood malignancies. Wilms' tumor rates in Brazil are among the highest in the world. This prompted the Brazilian Wilms' Tumor Study Group to conduct a hospital-based, multicenter, case-control investigation of environmental risk factors for the disease. Between April 1987 and January 1989, the authors collected information on relevant occupational exposures by interviewing the parents of 109 Wilms' tumor cases admitted to hospitals in Sao Paulo, Salvador, Belo Horizonte, and Jau. Also interviewed were the parents of 218 age- and sex-matched control children who had been admitted for treatment of nonneoplastic diseases to the same or nearby hospitals. Odds ratios (ORs) adjusted for income and education were calculated by conditional logistic regression. Consistently elevated risks were seen for farm work involving frequent use of pesticides by both the father (OR = 3.24, 95% confidence interval (CI) 1.2-9.0) and the mother (OR = 128.6, 95% CI 6.4-2,569). These risk elevations were restricted to cases diagnosed after 2 years of age (ORs > 4), for paternal exposure, and after 4 years of age (OR = 14.8, 95% CI 2.2-98.8), for maternal exposure. Risk elevations were also more pronounced among boys (paternal exposure OR = 8.56, 95% CI 2.1-35.1; maternal exposure OR = 4.60, 95% CI 0.8-26.4) than among girls (paternal exposure OR = 1.31, 95% CI 0.4-4.1; maternal exposure OR = 2.03, 95% CI 0.5-8.9).