Birth characteristics and hepatoblastoma risk in young children

Although hepatoblastoma is a very rare childhood cancer, its incidence appears to be rising, especially among children with very low birth weight. With the exception of documented correlations with certain congenital anomalies, the etiology of hepatoblastoma remains largely unknown.

Using California's population-based cancer registry, the authors identified 113 children ages birth-4 years with hepatoblastoma who were diagnosed between 1988 and 1997. Ninety-nine of those 113 children (88%) were matched to a California birth certificate, and randomly selected controls from the same birth certificate files were matched to cases (4:1) according to the month and year of birth and gender. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using conditional logistic regression analyses.

A strikingly elevated risk of hepatoblastoma was found in children who were born with very low birth weight (< 1500 g; OR, 50.57; 95% CI, 6.59-387.97). A plot of the distribution by birth weight showed interesting peaks at birth weights < 1000 g and 3000-3499 g among cases. Children who weighed < 1000 g showed a statistically significant, linear trend toward being diagnosed at an older age (P = 0.036), which seemed to be explained in part by gestational age.

The results confirmed previously reported findings of an increased hepatoblastoma risk among children with very low birth weight and suggested that the etiology may differ between children with very low birth weight and children with normal birth weight.