Case-control study of perinatal factors and hepatoblastoma in children with an extremely low birthweight

Background: There is a significant association between hepatoblastoma and l ow birthweight. A case-control study was conducted to reveal risk factors f or hepatoblastoma in children of extremely low birthweight (< 1000 g). Methods: Prenatal and postnatal histories, including parental histories, of 12 hepatoblastoma cases and 75 birthweight-matched controls were compared. Results: The gestational age of the hepatoblastoma cases (23-32 weeks; medi an 25 weeks), tended to be lower than that of the controls (23-36 weeks; me dian, 27 weeks; P=0.072). The time for an infant's bodyweight to return to the same level as the birthweight also tended to be longer in hepatoblastom a cases than in controls (P=0.055). All hepatoblastoma cases received oxyge n therapy for a period of 4-508 days (median 114 days), which was significa ntly longer than the 0-366 days (median 62 days) in the controls (P=0.022). Furosemide was given to all hepatoblastoma cases and was used for a signif icantly longer period in these infants (6-460 days; median 89 days) than in the controls (0-241 days; median 44 days P=0.027). A univariate Cox regres sion demonstrated that the time taken to regain bodyweight at birth and the duration of both oxygen therapy and furosemide treatment were significantl y associated with the development of hepatoblastoma (hazard ratio (HR)=1.04 4, P=0.013; HR=1.006, P=0.001; and HR=1.007, P=0.001, respectively). Althou gh there were significant correlations between the factors, a multivariate Cox regression analysis identified the duration of oxygen therapy as a sign ificant independent risk factor (HR=1.006, P=0.001). Conclusions: Oxygen therapy and furosemide treatment, along with the rate o f growth, are risk factors for the development of hepatoblastoma in childre n of extremely low birthweight, and the duration of oxygen therapy is the m ost important factor in predicting the development of hepatoblastoma. Furth er studies are necessary to determine the real reasons for the development of hepatoblastoma and to protect children of low birthweight from the devel opment of cancer.