An evaluation from the Women's Health Initiative (WHI) found that not only are postmenopausal women who’re obese or obese. The risk of invasive breast cancer is higher in women of normal weight, but the danger also increases when a girl gains weight from obesity. The results were published online on June 11, 2015. JAMA Oncology.
A team of investigators from multiple medical centers studied data from 67,000 postmenopausal women who were enrolled within the WHI between 1993 and 1998. During that point, 3,388 invasive breast cancers were detected. The researchers analyzed the distribution of breast cancer across weight classes and calculated the risks for girls who were obese (body mass index, or BMI, 25 to 30), obese (BMI 30 to 35) and obese (BMI 30 to 35). , or very obese (BMI greater than 35) in comparison with women of normal weight (BMI 25 or less). They found that the danger of developing breast cancer increased from 17 percent to 59 percent in obese women with a BMI greater than 35. People who were at their original weight had a lower risk of breast cancer than those that maintained their original weight. Neither weight reduction nor using hormone therapy had a big effect on risk for girls of any weight.
You can calculate your personal risk on the National Cancer Institute website at www.cancer.gov/bcrisktool. The WHI evaluation can provide you with a greater idea of how being obese or obese may affect your risk.