Study Finds Link between Birth Size and Breast Cancer Cases
Women who were big at birth are at greater risk of breast cancer, a new study has found.
High birth size could account for five per cent of breast cancers in developed countries such as the UK, said scientists.
Weight, body length and head circumference were all correlated with breast cancer risk in adulthood.
Of the three, the most significant association was with body length.
Women who measured 51 centimetres or more at birth were 17 per cent more likely to develop breast cancer than those who had a birth length of 49 centimetres.
Birth record data showed that every 0.5 kilogram increase in birth weight was associated with a significant six per cent increase in breast cancer risk.
A team led by Professor Isabel dos Santos Silva, from the London School of Hygiene and Tropical Medicine, analysed findings from 32 investigations looking at 22,058 cases of breast cancer among more than 600,000 women.
Most of the patients lived in developed countries, and they included both post-menopausal and younger women.
Scientists have linked birth size and breast cancer before, but the findings from individual studies have been inconsistent.
The new paper, published in the online journal PLoS Medicine, provides the strongest evidence yet that birth size is related to breast cancer risk in later life.
Experts still do not know the reason for the association, but birth size is thought to reflect conditions in the womb that influence cancer development.
Prof Santos Silva said: "Our study indicates that birth size is a marker of susceptibility to breast cancer in adulthood, at least in developed countries. …