Women whose mothers have wide hips may be more likely to develop breast cancer, media reports have claimed.
UK researchers found breast cancer rates were more than three times higher among women whose mothers had wide hips. Previously, it has been suggested that oestrogen can increase the risk of breast cancer in some hormone-sensitive women.
What is the research?
The reports are based on an international study by researchers from the US, UK and Finland. They hypothesised that higher sex hormone concentrations at puberty could produce wider hips, and these could act as markers of increased breast cancer risk in the next generation.
For the study, the researchers studied the maternity records of 6,370 women born in Helsinki, Finland, between 1934 and 1944.
Their mothers' pelvic bones were measured during routine antenatal care. Specifically, measurements of the intercristal diameter, the widest distance between the wing-like structures at the top of the hip bones, were recorded.
Between 1971 and 2003, the researchers followed up the women for any cases of breast cancer or death using the national registers of all hospital admissions and deaths in Finland. Breast cancer was diagnosed in 300 women, of whom 48 died from the disease. The mean age of breast cancer diagnosis was 54.
The risk of breast cancer was calculated to be 3.7 times higher in women whose mother's intercristal distance was more than 30cm than in those whose mothers had smaller hips. The risk was also increased if the mothers had rounded iliac hip bones. Among women born to mothers who had one or more children previously, the risk of breast cancer increased by seven fold.
What do researchers say?
Lead researcher David Barker, professor of developmental origins of health and disease at the University of Southampton, said: 'Our findings show for the first time that the growth spurt of girls at puberty is strongly associated with the risk of breast cancer in their daughters.'
The study findings support the hypothesis that wide, round hips reflect high levels of sex hormone production at puberty, which persist after puberty and adversely affect breast development of their daughters in early gestation.
'A woman's hips are shaped at puberty when the growth of her hip bones is controlled by sex hormones, and also influenced by the level of nutrition', explained Professor Barker.
'Every woman has a unique sex hormone profile established at puberty and persists through her reproductive life.'
Professor Barker proposed that catechol oestrogen, a metabolite of oestradiol, might be behind the increased risk of breast cancer: 'High catechol oestrogen concentrations in the maternal circulation could produce genetic instability in differentiating breast epithelial cells which would make the breast vulnerable to cancer in later life.'
What do the experts say?
Dr Lesley Walker, Cancer Re-search UK's director of cancer information, said that the importance of oestrogen in stimulating the growth of breast cancer was well known.
'While this study appears to show an effect that crosses a generation, we would need to see the results confirmed in follow-up studies.'
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