Women with a high risk of developing breast cancer based on family history and genetic risk can still reduce the chance they will develop the disease in their lifetimes by following a healthy lifestyle, new research led by the Johns Hopkins Bloomberg School of Public Health suggests.
White women who are at high risk but who had a low body mass index (a marker for obesity), who did not drink or smoke and who did not use hormone replacement therapy, had roughly the same risk as an average white women in United States, the researchers found. The average chance that a 30-year-old White woman will develop breast cancer before she is 80 is about 11 percent.
The researchers found that roughly 30 percent of breast cancer cases could be prevented by modifying known risk factors – say, by drinking less alcohol, losing weight and not taking hormone replacement therapy. More importantly, the study found that a larger fraction of total preventable cases would occur among women at higher levels because of genetic risk factors, family history and a few other factors that cannot be modified.
The findings, published May 26 in JAMA Oncology, are a first step in understanding how advances in the field of genetics can be used for developing precision prevention strategies to help women improve their odds of avoiding breast cancer. Breast cancer remains the most common form of malignancy diagnosed in women in Western developed countries, with an estimated 232,000 new cases diagnosed in the United States in 2014. Roughly 40,000 women die in the United States from breast cancer each year.