This Breast Cancer Risk Assessment Tool has been designed for a health professional to project an individual patient's estimate of invasive breast cancer risk
Even when a woman with breast cancer has a risk factor, there is no way to prove that it actually caused her cancer. There are different kinds of risk factors
Obesity is also a risk factor for breast cancer in postmenopausal women. More information about breast cancer risk factors is found in NCIs publication What You Need To Know About Breast Cancer