Cancer Treatment Centers of America

Breast cancer risk factors

Each year, more than 190,000 people are diagnosed with breast cancer. According to the National Cancer Institute, the incidence of breast cancer in the United States has decreased by about two percent from 1999 to 2006. The reason for the decrease is not completely understood.

Knowing the risk factors for breast cancer may help you take preventative measures to reduce the likelihood of developing the disease.

Invasive breast cancer risk factors


  • Gender: Women are at greater risk than men for developing invasive breast cancer.
  • Race: Invasive breast cancer rates are lower among black, Asian and Hispanic women and higher among white women.
  • Age: Women who are age 55 years and older are at greater risk for invasive breast cancer than women under age 55.


  • BRCA1 and BRCA2 mutations: BRCA1 and BRCA2 are genes that help repair damaged DNA. Mutations in BRCA1 and BRCA2 can be inherited from a family member and are the most common causes of inherited breast cancer, which is most often invasive.
  • Other genetic mutations: Other genetic mutations that may increase a woman’s risk of invasive breast cancer include ATM, p53, CHEK2, PTEN and CDH1. These mutations are rare and do not increase risk as much as BRCA1 and BRCA2.
  • Family history of breast cancer: Having a family history of breast cancer, particularly women with a mother, sister or daughter who has or had breast cancer, may double the risk.


  • Dense breast tissue: Women with less fatty tissue and more glandular tissue in the breast may be at higher risk for developing invasive breast cancer.
  • Obesity: After menopause, fat tissue may contribute to increases in estrogen levels, and high levels of estrogen may increase the risk of breast cancer. Weight gain during adulthood and excess body fat around the waist may also play a role.
  • Not having children: Women who have had no children, or who were pregnant later in life (over age 35) may have a greater chance of developing breast cancer. Breast-feeding may help to lower the risk of breast cancer.

Understanding risk factors

Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer. Not having risk factors doesn’t mean that you will not get cancer. If you think you may be at risk, you should discuss it with your doctor.

Advanced genomic testing

genomic tumor assessment

We use advanced genomic testing to examine a patient's tumor on a cellular level. This innovative tool can help us find what's driving the cancer's growth and offer patients more precise treatment.