Research links birthweight and childhood cancer

Recent research conducted by the International Childhood Cancer Cohort Consortium, led by Professor Terry Dwyer of Oxford University, has confirmed a link between birthweight and childhood cancer

The International Childhood Cancer Cohort Consortium (I4C) is an alliance of several large-scale prospective cohort children studies. The group pools data and biospecimens from individual cohorts to study various modifiable and genetic factors in relation to cancer risk.

Childhood Cancer

The George Institute for Global Health’s, UK Executive Director, based at Oxford University, Professor of Epidemiology Terry Dwyer has been leading the International Childhood Cancer Cohort Consortium’s initiative to better understand the role of early-life exposures in childhood cancers.

The research from the I4C confirmed that childhood cancer is linked to birthweight. In addition, the study uncovered that childhood cancer incidences appear to be rising by about 1% per year in developed countries. The risk increased for all cancers by 26% for each kilogram increase in birthweight.

Early-life exposures and risk of Leukemia 

The risk for leukemia appears to be higher in younger children than all other cancers combined. However, for children that were diagnosed at three years of age or older, cancers other than leukemia are more strongly related to high birthweight. 

One of the factors that the I4C’s research ruled out was that it does not correlate with the mother’s weight gain. This is even though the mother’s weight gain might contribute to birthweight.

Professor Dwyer explains, “We have been able to compile a significant amount of evidence that effectively shows that childhood cancer incidence rises with increasing birthweight. While we observed a correlation between increased birthweight and higher risk of cancer incidence in children, there were no significant interactions with maternal pre-pregnancy overweight or pregnancy weight gain.”

The I4C illustrates the power of collaboration because it allows for ongoing analysis of a wider range of potential factors and causes of childhood cancers.

Other previous studies have shown the relationship between childhood cancers and high birthweights, but this collaboration brings about a wider range of potential factors like maternal age, marital status, education level, smoking propensity, previous live births, diabetes, pre-pregnancy BMI, and total pregnancy weight gain. All of these other metrics can now be included in the research and analysis.

 What’s Next?

 
The I4C researchers are planning to follow this study up with several lines of inquiry, including:

• Looking at data in new cohorts such as in Japan and China to see whether this association exists there as well
• Investigating other factors that have some relationship to birth weight, such as birth order, to see whether  the association is similar in infants of different birth order, and
• Making cord blood measurements from infants in the cohorts to determine whether growth hormones of various types explain what we have found.

To summarize the current research and information on the topic, Professor Dwyer says, “At The George Institute we are focused on the prevention and treatment of non-communicable diseases, like cancer. I am more optimistic that we’ll find ways of preventing childhood cancer than I was when we started this study 10 years ago.

“We know that there are no easy answers, but we are assembling more clues, like this piece of evidence, which will help us fill in the puzzle. Additional research into childhood cancer is needed so that we can provide actionable solutions to improve outcomes for future generations.”

George Clinical is a Asia Pacific Clinical Research Organisation, the George Institute for Global Health acts as its parent company.