PURPOSE: In the United States, lymphoma represents approximately one-third of all malignancies in those less than 20 years of age. As most cases are of unknown etiology, the identification of risk factors for the prevention of childhood lymphoma is critical. Parental and birth characteristics are often evaluated in studies of childhood cancer to determine the role of inborn variation on disease risk. Thus we sought to evaluate the role of parental and birth characteristics on the risk of childhood lymphoma.
MATERIAL AND METHODS: Cases (n=374) were obtained from the Texas Cancer Registry (TCR) and limited to children born in Texas during or after 1995 and diagnosed with a lymphoma between 1995-2011. Diagnostic information came from the TCR, and case birth characteristic data was obtained from linked Texas birth certificates provided by the Center for Health Statistics. A randomly selected group of 10 controls for each case with subsequent birth characteristic data available was obtained from linked birth certificates. Multinomial logistic regression was used to generate relative-risk ratios (aRRR) and 95% confidence intervals (CI), adjusted for relevant covariates, to evaluate the association between several parental and birth characteristics and lymphoma risk (overall and by subtype).
RESULTS: Most parental and birth characteristics were not associated with risk of childhood lymphoma. However, two factors were associated with lymphoma risk overall and by subtype: maternal race/ethnicity and infant sex. When compared to non-Hispanic white mothers, Hispanic mothers were more likely to have offspring that developed: 1) any lymphoma (aRRR: 1.09; 95% CI: 0.85-1.40) and 2) non-Hodgkin excluding Burkitt lymphoma (aRRR: 1.42; 95% CI: 0.96-2.11). The reverse was seen for non-Hispanic black mothers. There was also a disparity in risk by infant sex. Specifically, female children were at a decreased risk of developing all lymphomas (aRRR: 0.59; 95% CI: 0.47-0.74); Hodgkin lymphoma (aRRR: 0.65; 95% CI: 0.46-0.92); and Burkitt lymphoma (aRRR: 0.18; 95% CI: 0.10-0.33) when compared to male children. Additionally, paternal nativity was suggested to increase overall lymphoma risk (aRRR: 1.29; 95% CI: 0.96-1.73); an increase specifically suggested among those diagnosed with Hodgkin lymphoma (aRRR: 1.46; 95% CI: 0.93-2.32).
CONCLUSION: In this relatively large population-based study of these factors on the risk of childhood lymphoma, we found little evidence that parental and birth characteristics were strongly associated with disease risk.
