Birth characteristics and Wilms tumors in children in the Nordic countries: A register‐based case–control study

Abstract

Little is known about causes of Wilms tumor. Because of the young age at diagnosis, several studies have looked at various birth characteristics. We conducted a registry-based case-control study involving 690 cases of Wilms tumor aged 0-14 years, occurring in Denmark, Finland, Norway or Sweden during 1985, individually matched to five controls drawn randomly from the Nordic childhood population. Information on birth characteristics was obtained from the population-based medical birth registries. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression analysis. We observed a distinct association between Wilms tumor and high birth weight (4 kg) for girls (OR 1.97, CI 1.50-2.59) but not for boys (1.04, 0.78-1.38); overall, the OR was 1.43 (1.17-1.74). Among girls, risk increased by 28% (15-42%) per 500 g increase in birth weight. Large-for-gestational age girls also had a higher risk (2.48, 1.51-4.05), whereas no effect was seen for boys (1.12, 0.60-2.07). An association was seen with Apgar score at 5 min < 7 for both sexes combined (5.13, 2.55-10.3). ORs close to unity were seen for parental age and birth order. In our large-scale, registry-based study, we confirmed earlier observations of an association between high birth weight and risk of Wilms tumor, but we found an effect only in girls. The higher risk of infants with low Apgar score might reflect hypoxia causing cell damage, adverse side effects of neonatal treatment or reverse causation as low Apgar score might indicate the presence of a tumor.Renal tumors in children are rare. Its major subtype, Wilms tumor or nephroblastoma, constituting >95% of all childhood renal tumors, is an embryonal malignancy arising from remnants of the immature kidney.

Birth order and risk of childhood cancer in the Danish birth cohort of 1973–2010

“…A large registry-based study in the Nordic countries of 3,983 CNS tumor cases confirmed our finding of no association with birth order, acknowledging some overlap in the Danish cases with our birth cohort [10]. In a similar study in the Nordic countries involving 3,298 cases of Wilms tumor, the odds ratio of later-born children compared with firstborn children was 0.98, again consistent with our findings [11]. Overall, there appears to be little evidence of an association between birth order and childhood solid tumor risk.…”

“…Many studies have investigated the possible association between birth order and risk of childhood cancer, although the evidence to date has been inconsistent [1,[4][5][6][7][8][9][10][11][12]. As birth order is relatively straightforward to record, either through routine data sources such as birth registries or through questionnaire-based studies, where it is generally acknowledged to be well reported [13], it has often been used as a surrogate marker for in utero and/or childhood exposures.…”

Fetal Growth and Childhood Cancer: A Population-Based Study

“…7 Our findings confirmed the earlier observations of an increased risk of Wilms tumors at high birth weights (.50% increased risk at birth weights .4000 g compared with the reference group [3000-3499 g]) and being LGA (.100% increased risk) in girls. In data from the Children' s Oncology Group in the United States, the association between high birth weight (.4000 g) and Wilms tumors was strongest among patients with perilobar nephrogenic rests, present in 17% of the girls and 9% of the boys.…”

“…High birth weight (.4000 g) generally has been associated with a 30% to 50% increased risk of Wilms tumors, 7,25,26 although Nordic data have shown that the effects of high birth weight and being LGA were restricted to girls. 7 Our findings confirmed the earlier observations of an increased risk of Wilms tumors at high birth weights (.50% increased risk at birth weights .4000 g compared with the reference group [3000-3499 g]) and being LGA (.100% increased risk) in girls.…”

“…4 High birth weight has also been linked to development of other childhood tumors such as cancers of the central nervous system (CNS), lymphomas, and Wilms tumors (nephroblastoma), but results have been inconclusive. [5][6][7] Earlier Nordic population-based studies have also shown that increased head circumference is positively associated with childhood brain cancer, suggesting that brain pathologic conditions originate in fetal life. 8,9 Studies of pregnancy risk factors are made difficult by the low relative frequency of different childhood tumors.…”