There is increasing interest in the relationship between breast cancer and obesity around the waist versus overall obesity.

Researchers in England say gaining one skirt size over any 10 years between a woman’s mid-20s to mid-50s can be dangerous.

The scientists base their findings on almost 93,000 women taking part in the UK Collaborative Trial of Ovarian Cancer Screening.  The women were all aged 50-plus, had gone through menopause and had no known breast cancer when they entered the study between 2005 and 2010.

During the monitoring period, close to 1100 women developed breast cancer.  As expected, infertility treatment, family history of breast/ovarian cancer, and use of hormone replacement therapy were all significantly associated with a heightened risk of being diagnosed with the disease, while pregnancies were protective.

But after taking account of other influential factors, increases in skirt size emerged as the strongest predictor of breast cancer risk.

In fact, the researchers say such a gain is linked to a 33 per cent greater risk of developing breast cancer after menopause.

The study is published in the online journal BMJ Open.