Washington: A new study has revealed that overall weight gain during adulthood, especially thickening of the waist area increases the risk of postmenopausal breast cancer by 33 percent.
The study was based on almost 93,000 women aged over 50taking part in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) in England who had gone through the menopause, and had no known breast cancer when they entered the study between 2005 and 2010, also most of them were white, educated to university degree level, and overweight at the point of study entry, with a BMI of 25-26.
After a monitoring period of three to four years they were asked about continuing use of HRT; their general health; a subsequent diagnosis of cancer; and lifestyle, including how much they smoked and drank, it was found that 1090 women developed breast cancer, giving an absolute risk of just over 1%. As expected, 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.
At the age of 25, the women's average skirt size had been a UK 12, and when they entered the study at the average age of 64, it was a 14. Skirt size increased over the course of their adult lives in three out of four of the women and it was revealed that going up one skirt size every 10 years was associated with a 33 percent greater risk of developing breast cancer after the menopause; going up two skirt sizes in the same period was associated with a 77 percent greater risk.
The researchers estimate that the five year absolute risk of postmenopausal breast cancer rises from 1 in 61 to 1 in 51 with each increase in skirt size every 10 years. Adding BMI to the calculations did not significantly improve the prediction of risk and earlier expanding waist line has been linked to other cancers, including those of the pancreas, lining of the womb, and ovaries, they point out, possibly because midriff fat is more harmful.