MedWire News: The risk for retinoblastoma in children under 6 years of age is associated with paternal age and maternal birthplace and ethnicity, show US study results.
Specifically, risk for the bilateral form of the disease was higher among children born to fathers aged 30 years and above, compared with younger fathers, and risk for the unilateral form was higher among children with Hispanic, US-born mothers, compared with foreign-born Hispanic mothers.
Speaking of the latter finding, co-author Julia Heck (University of California, Los Angeles) said in a press statement: "We believe this is because women born in Mexico who come to the United States and have children have very healthy behaviors in the perinatal period immediately before and after giving birth."
Indeed, Heck and team explain in Cancer Causes & Control that "US-born Mexican women are more likely to have used tobacco, drugs, and alcohol in pregnancy and to have generally poorer diets, in comparison with Mexican immigrant women."
The study examined data for 609 pediatric patients with retinoblastoma (187 bilateral) and 209,051 healthy control patients matched by year of birth, to identify links between disease occurrence and perinatal factors reported on birth certificates.
Among unilateral patients, maternal birthplace in Mexico was 24% less common than maternal birth in the USA, while children with US-born Hispanic mothers were 34% more likely to have retinoblastoma than their peers whose mothers were foreign born.
The average paternal age among children with bilateral retinoblastoma was 30.2 years, and analysis showed that the risk increased when fathers' age was 30-34 years (crude odds ratio [OR]=1.44) or 35 years and above (OR=1.73).
"This association... may be explained by a higher occurrence of new germline mutations with increasing age," suggest Heck and co-workers who add that the finding is also consonant with the observation that new germline mutations predisposing to retinoblastoma are inherited most often from fathers.
The team also reports a decreased risk for unilateral disease among children of parents with less than 8 years of education, an increased risk among male children, and an association between bilateral disease and maternal history of sexually transmitted diseases during pregnancy.
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