Can the “Hispanic Paradox” Shed Light on Childhood Cancer Risk?

Abstract

Abstract The “Hispanic epidemiologic paradox” is the commonly observed phenomenon that foreign-born Hispanic mothers who emigrate to the United States have consistently good pregnancy outcomes, such as decreased rates of low birthweight, despite high levels of poverty. We examined whether this advantage extends to childhood cancer risk. Methods: The study included all children born in California from 1983–2007. Birthrolls were linked to California Cancer Registry records of children ages <6 who were diagnosed with cancer 1988–2007 (N = 8710 cases, 9,519,438 controls). The mother's Hispanic origin, ethnic ancestry, and country of birth were ascertained from the birth certificate. We used Cox proportional hazard models to estimate the risk for cancer based upon maternal birthplace and ethnic ancestry. Models stratified by tumor subtype and adjusted for maternal and paternal age. Summary of results: The children of foreign-born Hispanic women had lower rates of several cancers [acute lymphoblastic leukemia (ALL; odds ratio (OR) = 1.05, 95% confidence interval (CI) = 0.96–1.14); glioma (OR = 0.51, 95% CI, 0.43–0.59); neuroblastoma (OR = 0.46, 95% CI, 0.39–0.55)] in comparison to the children of US-born Hispanic women [ALL (OR = 1.23, 95% CI, 1.11–1.37); glioma (OR = 0.75, 95% CI, 0.62–0.90); neuroblastoma (OR = 0.63, 95% CI, 0.51–0.78); referent group was the children of US-born Whites]. The odds for rhabdomyosarcoma and acute myeloid leukemia were equivalent between Hispanics regardless of maternal place of birth. Hepatoblastoma was higher among the children of foreign-born mothers (OR = 1.35, 95% CI, 0.87–2.10) than those of US-born Hispanic mothers (OR = 0.93, 95% CI, 0.56–1.55) while bone tumors were higher among the children of US-born mothers (OR = 2.08, 95% CI, 1.11–3.88) compared to the children of foreign-born mothers (OR = 0.73, 95% CI, 0.38–1.41). Conclusions: With notable exceptions, the children of foreign-born Hispanic mothers tended to have cancer rates lower than those of US-born Hispanic mothers. Risk factors identified as driving the Hispanic paradox may be fruitful for study among these childhood cancer types.