High body fat levels could increase breast cancer risk. A study led by researchers from Memorial Sloan Kettering Cancer Center has reported this finding in Jama Oncology.
“In postmenopausal women with normal BMI, relatively high body fat levels were associated with an elevated risk of invasive breast cancer and altered levels of circulating metabolic and inflammatory factors. Normal BMI categorization may be an inadequate proxy for the risk of breast cancer in postmenopausal women,” the study concluded.
Obesity is associated with an increased risk of breast cancer, including the estrogen receptor (ER)–positive subtype in postmenopausal women. Whether excess adiposity is associated with increased risk in women with a normal body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) was unknown before this study.
The recognition of obesity as a risk factor for several cancers is largely based on the use of anthropometric indices, such as body mass index (BMI). However, BMI is a crude measure of body size that does not discriminate between adiposity and muscle.
Recent evidence suggests that a subset of women with normal BMI and excess body fat may be at increased risk for breast cancer. This is the evidence that has now been validated by this study.