A hormone that boosts growth in kids may lead to breast cancer, and women with high levels are at higher risk, according to a new study by UK scientists.
It is a known fact that cancer is cause by uncontrolled division of cells in the body.
The hormone, IGF-1, stimulates cell division, especially during childhood. It is also being investigated as an anti-ageing treatment.
Information from nearly 5000 women across 12 countries was analysed by Cancer Research UK scientists at the University of Oxford.
The results amongst these women suffering from breast cancer showed that the 20 per cent of women with the highest blood levels of the growth factor were 28 per cent more likely to develop the disease than the 20 per cent with the lowest levels.
Moreover, the effect is more pronounced with a certain type of breast cancer that responds to the female hormone oestrogen.
"Over the last few years there has been increasing interest in the possible link between growth factors and breast cancer, but the results have been inconsistent. Putting together all the information available worldwide gives us conclusive evidence that the higher a woman's blood levels of IGF-I, the higher her risk of breast cancer," the Independent quoted Professor Tim Key, lead author of the study, as saying.