Prenatal Ambient Pesticide Exposure and Childhood Retinoblastoma

Retinoblastoma is a rare tumor of the retina, most commonly found in young children. Due to the rarity of thischildhood cancer, few studies have been able to establish prenatal pesticide exposure as a risk factor. We conducted a population-based case-control study using cases under the age of 6 identified from the California Cancer Registry, and controls randomly selected from California birth certificates. Frequency matching cases to controls by age resulted in 221 cases of unilateral retinoblastoma and 114 cases of bilateral retinoblastoma, totaling 335 cases and 123,166 controls. We linked addresses from birth certificates with Pesticide Use Reports, in order to assess exposure to pesticides within 4000m of the residence during pregnancy. Odds ratios were computed for individual pesticides using unconditional logistic and hierarchical regression models stratified by laterality. We found that exposures to acephate (OR: 1.70, 95% CI: 1.20, 2.41) and bromacil (OR: 1.87, 95% CI: 1.07, 3.26) were associated with increased risk for unilateral retinoblastoma. In addition to acephate, we found that pymetrozine (OR: 1.45, 95% CI: 1.00, 2.08) and kresoxim-methyl (OR: 1.60, 95% CI: 1.00, 2.56) were associated with retinoblastoma (all types combined). These findings suggest that prenatal ambient pesticide exposure from residing near agricultural fields may play a role in the development of childhood retinoblastoma