Breast-feeding and Wilms tumor: a report from the Children's Oncology Group.

OBJECTIVE

Previous research has shown that breast-feeding offers many nutritional benefits to children including protection against infection and possibly a decreased risk of childhood cancer. We investigated the association between breast-feeding and Wilms tumor, a childhood kidney tumor.

METHODS

We used data from a large case-control study in the United States and Canada. Cases were children under age 16 years who were diagnosed with Wilms tumor from 1999 to 2002 and were participating in the National Wilms Tumor Study. Controls were identified by random-digit dialing and were age and region matched to cases. Mothers of 501 cases and 480 controls provided information on breast-feeding by telephone interviews.

RESULTS

Breast-feeding was associated with a reduced risk of Wilms tumor [adjusted odds ratio (OR) = 0.7; 95% confidence interval (CI) = 0.5-0.9]. Longer duration did not provide any additional reduction in risk. When stratified by maternal education, breast-feeding lowered risk among children whose mothers had less than a college education (OR = 0.6; 95% CI = 0.4-0.8) but not for mothers who had a college degree or more (OR = 1.1; 95% CI = 0.6-1.9).

CONCLUSIONS

The results of this study are suggestive of an association between breast-feeding and Wilms tumor, but further research is needed to confirm this relationship.