The study aims to determine whether a larger body size in childhood protects against a risk of pre-menopausal breast cancer.
- Topic: Breast cancer
- Institution: Murdoch Children's Research Institute
- Country: Australia
- Status: Ongoing
The study aims to determine whether a larger body size in childhood protects against a risk of pre-menopausal breast cancer.
Obesity is a risk factor for several adult cancers, but the specific risk associated with it in childhood is not well understood because of limited evidence from prospective studies – those that take measurements of for example weight and height in children and follow them until cancer occurs.
Determining the contribution of childhood obesity is particularly important for pre-menopausal breast cancer because of the surprising finding in studies based on adults’ recall of their height and weight that girls who are overweight have a reduced risk of this type of breast cancer.
The study aims to determine whether a larger body size in childhood protects against a risk of pre-menopausal breast cancer.
It also seeks to gain an understanding of why this might be so by measuring hormones and other metabolites in the blood which could be the mechanism through which obesity exerts its possible effect on risk.
The i3C cohort consortium provides a unique opportunity to examine this relationship prospectively using childhood measurements of obesity.
It has assembled data on 41,015 participants, including 21,217 girls, from USA, Finland, and Australia – first measured in childhood and followed for approximately 40 years, among whom approximately 500 pre-menopausal invasive breast cancer cases have occurred.
The available dataset includes height and weight measurements at several points in childhood, as well as girth and skinfold measures, which presents an opportunity to investigate whether the amount and distribution of body fat is important in predicting risk.
The availability of stored serum or blood spots on >6,000 will enable examination of the potential mediating role of many biological variables.
To be able to do this investigation we will need to obtain information from cancer registries on how many of the 21,217 girls developed pre-menopausal breast cancer in adulthood. This will then be linked to the data on obesity in the girls to determine the associated risk.
Blood stored by i3C from childhood will then be analysed to determine whether hormone levels in childhood and other metabolites might also be associated with risk of this breast cancer.
Whether obesity is a protective factor for pre-menopausal breast cancer must be addressed as public health programs to combat childhood obesity are implemented.
Because the i3C Consortium possesses the only prospective dataset that includes childhood measures of obesity that can then be linked to risk of pre-menopausal breast cancer, the evidence the study produces will be completely unique.
It will be relied upon for some time to guide the development of public health programs in childhood aimed at pre-menopausal breast cancer prevention.
We are delighted to investigate an important research question regarding the causal link between body mass index in childhood and pre-menopausal breast cancer. Pooled data from the International Childhood Cardiovascular Cohort (i3C) Consortium will provide a unique opportunity to prospectively examine this relationship to identify previously unknown and potentially modifiable causes of pre-menopausal breast cancer. It is our expectation this will provide insights into new pathways for breast cancer prevention and provide important guidance to public health programs.
Professor Terry Dwyer