UCLA

Childhood cancer is a rare disease that may be triggered prenatally. The few known causes of pediatric cancers include ionizing radiation, Down syndrome, and some genetic or chromosomal anomalies. Additional risk factors have been suggested, but due to the rarity of childhood cancers, it has been difficult to establish causes and hence targets for prevention. We investigated ultraviolet radiation (UVR), pesticides, and maternal dietary patterns as possible risk and protective factors. Studies have shown that higher solar UVR may be related to lower risk of some cancers in adults and children. In a large, population-based case-control study we tested the hypothesis that childhood cancers may be influenced by UVR. Cancers in children ages 0 to 5 years were identified from California Cancer Registry records for 1988-2007 and linked to birth certificate data. Controls were sampled from birth certificates. Based on birth address, we assigned UVR exposure using a geostatistical exposure model developed with data from the National Solar Radiation Database. Our preliminary findings suggest that UVR during pregnancy may decrease the odds of some childhood cancers. In the same study population we evaluated the associations of exposure to specific pesticide types during pregnancy with glial tumors in young children in California using a validated geographic exposure model. We observed increased odds of astrocytoma for residential pesticide exposure to herbicides, insecticides and fungicides, as well as for several chemical classes of pesticides. Additionally, using data from a multi-institutional case-control study of retinoblastoma in the United States and Canada, we investigated the association of maternal prenatal diet with the risk for unilateral retinoblastoma among children less 15 years of age. Previous studies have shown that mother's diet during pregnancy may affect her offspring's risk of cancer. Our results suggest that a dietary pattern with high fruit and vegetable consumption and low consumption of fried foods and sweets during pregnancy, as well as a dietary pattern with high fruit and vegetable consumption and low consumption of red and cured meats, may reduce the odds of unilateral retinoblastoma in offspring.