Abstract
PURPOSE: We conducted a case-control study to examine the role of parents' nutrient intake before their child's conception in the child's risk of sporadic bilateral retinoblastoma, which results from a new germline RB1 mutation. METHODS: Parents of 206 cases from 9 North American institutions and 269 friend and relative controls participated; fathers of 182 cases and 223 controls and mothers of 202 cases and 260 controls provided useable information in telephone interviews on their diet in the year before the child's conception. We also asked parents about supplements, a significant source of nutrients in users. RESULTS: Father's intake of dairy-associated nutrients and his use of calcium supplements were associated with decreased risk, while his intake of copper, manganese, and vitamin E was associated with increased risk. Mother's use of multivitamins close to conception was associated with lower risk as was her intake of several micronutrients found in these supplements. In analyses to elucidate the primary factor from multiple correlated factors, the most robust findings were for father's calcium intake (adjusted OR = 0.46-0.63 for 700 mg increase) and calcium supplement use (OR = 0.35-0.41) and mother's multivitamin use (ORs 0.28-0.48). CONCLUSIONS: There are few directly relevant studies but some data indirectly support the biologic plausibility of the inverse associations with father's calcium intake and mother's use of multivitamins; however, we cannot rule out contributions of bias, confounding, or chance. Our findings provide a starting point for further investigation of diet in the etiology of retinoblastoma and new germline mutation generally.