Unchangeable Risk Factors

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Risk Factors


Women are at greater risk of developing breast cancer. The risk of a man developing breast cancer is significantly lower.


Your risk of developing breast cancer increases as you get older.  About 2 out of 3 invasive breast cancers occur in women 55 years of age or older.


About 5% to 10% of breast cancers are hereditary.  This means the cancer is caused by a gene mutation, which was passed down from a parent.

The BRCA1 and BRCA2 genes are the most common causes of hereditary breast cancer.  Breast cancers caused by these genes are more often found in younger women, and can affect both breasts.  In the United States, BRCA mutations are common in Jewish women of Ashkenazi (Eastern European) origin; however, they can occur in anyone.  Genetic testing can be done to find such mutations.  If you are considering genetic testing, it is important to speak with a healthcare professional first to better understand the procedures and if it is the right option for you.

To learn more about genetic mutations which may cause breast cancer, visit: American Cancer Society.

Family history

The risk of breast cancer increases in women who have a relative on either their mother’s or father’s side of the family.  However, less than 15% of women who have breast cancer have a family history of the disease.  Therefore, the majority of women who get breast cancer have no family history at all.

Personal history

A women with breast cancer in one breast has an increased risk of getting a new cancer in another part of the same breast, or the other breast.  This is not the same as the return of the first breast cancer.

Race and ethnicity

Caucasian women are more likely to develop breast cancer but African American women are more likely to die from it.  The risk of developing breast cancer in younger women is higher for African American women as well.  The risk of developing and dying from breast cancer is lower in Asian, Hispanic, and Native American women.

Breast Density

Women with dense breast tissue have an increased risk of developing breast cancer.  Age, menopause, pregnancy, genetics, and some drugs may affect the density of breast tissue. 

Benign Breast Conditions

Some women with benign breast conditions have an increased risk of developing breast cancer.

To learn more on benign breast conditions which may cause cancer, visit: American Cancer Society.

Exposure to Diethylstilbestrol (DES)

Diethylstilbestrol (DES) is an estrogen-like drug which was given to some women in the 1940s through the 1970s.  If you or your mother (while she was pregnant with you) took DES, it may have increased your chance of developing breast cancer.


If you had your menstrual cycle start before the age of 12, you may have an increased risk of developing breast cancer.


If you started menopause after 55 years of age, you may have an increased risk of developing breast cancer. 

Previous chest radiation

If you were treated with radiation therapy to the chest area as a child, you may have an increased chance of developing breast cancer.

To take a breast cancer risk assessment test, visit: National Cancer Institute at the National Institutes of Health.




American Cancer Society 

Centers for Disease Control and Prevention