[Breastfeeding and childhood leukemia and lymphoma]

In the last 30 years there has been an increase in the incidence rate of childhood cancer in the western world. Although the 5-year survival rate from childhood cancer has increased significantly over the years due to advances in treatment technologies, cancer is still one of the leading causes of death among children in westernized countries. Leukemia and lymphoma are two of the most common cancer types in children and together account for about 45% of all childhood cancers. Nevertheless, very little is known of the etiology of childhood leukemia and lymphoma. Several studies had looked into the question of a relationship between infant nutrition--breastfeeding or lack thereof--and the risk of childhood leukemia and lymphoma as part of the "infective agent theory". This review aims to describe the current scientific evidence regarding the possible connection between breastfeeding and childhood malignancies, with an emphasis on childhood and adolescent leukemia and lymphoma. To that end, a systematic review of past studies has been conducted using Pubmed. Furthermore, the bibliographies of the relevant studies found on Pubmed were consulted. Studies were divided into two groups: original studies, and systematic reviews and meta analyses. Based on the Literature review, it is evident that the results are still inconclusive--some studies found a connection between breastfeeding and a lower risk of childhood leukemia and lymphoma, while others found no connection. The variability in breastfeeding and childhood cancer rates among the different populations where studies were conducted is large. In view of that variability and the differing results of former studies, there is a need to continue research. Israel, with characteristics of both a westernized country and a more traditional society with respect to parity and breastfeeding, is a good place to conduct such a study, with possible important implications for public health.