Skirt Size Increase Linked to Postmenopausal Breast Cancer

Going up a skirt size in middle-age can significantly increase the risk of postmenopausal breast cancer, according to new research. Researchers from the Universities of London and Manchester (UK) examined data from 93,000 women taking part in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS). The women were all aged over 50, had gone through the menopause, and had no known breast cancer when they entered the study between 2005 and 2010. On joining the study the women provided detailed information on height and weight; reproductive health; fertility; family history of breast and ovarian cancer; and use of hormonal contraceptives and HRT. They were also asked about their current skirt size, and what it had been in their 20s. After a monitoring period of 3-4 years, the women were asked about continuing use of HRT; their general health; a subsequent diagnosis of cancer; and lifestyle, including how much they smoked and drank. Results showed that 1090 women developed breast cancer during the monitoring period, giving an absolute risk of just over 1%. As predicted, infertility treatment, family history of breast/ovarian cancer, and use of HRT were all significantly associated with a heightened risk of being diagnosed with the disease, while pregnancies were protective. However, an increase in skirt size emerged as the strongest predictor of breast cancer risk. Going up 1 skirt size every 10-years was associated with a 33% greater risk of developing breast cancer after the menopause; while going up 2 skirt sizes in the same period was associated with a 77% greater risk. Results also showed that going down a skirt size was associated with a decreased risk of breast cancer. The association of skirt size with breast cancer risk was independent of BMI. The researchers concluded: “Although the exact mechanism of these relationships need to be better understood, there is a suggestion that body fat around the waist is more metabolically active than adipose tissue elsewhere.”