Breast cancer is the most common cancer in American women except for skin cancers.
Researchers at the American Cancer Society estimate that there will be 252,710 new cases of invasive breast cancer in women in the United States in 2017. Some 40,610 women will die from the disease.
In addition, there will be 63,410 cases this year of carcinoma in situ, abnormal cells that may be an early form of cancer.
Over a lifetime, a woman living in the United States has a 12.4 percent risk - one in eight - of being diagnosed with breast cancer.
Scientists have now identified at least five subtypes of breast cancer.
In the 1980s and 1990s, breast cancer rates rose. Scientists believe that the increases may be explained by the growing trend toward delayed childbearing and having fewer children, both known risk factors for breast cancer.
The good news is that death rates from breast cancer have declined 39 percent from 1989 through 2015. About 322,600 breast cancer deaths have been averted, largely the result of earlier diagnosis and new treatments.
Read more about this in the New York Times at https://www.nytimes.com/2017/10/06/health/breast-cancer-rates-united-states.html