Sex
The overwhelming majority of breast cancers occur in women. It does also occur in men.
The ratio from woman to man is 135:1.

Age
As a woman gets older her risk of breast cancer increases. For example, at age 30, 1 in 2200 women develop breast cancer but at age 80 approximately 1 in 10 develop breast cancer.  

Race
Caucasian women have the highest incidence of breast cancer.
 
Personal History of Breast or Ovarian Cancer
Women who have had a breast cancer in one breast have a higher risk of developing another breast cancer; either within the same breast or in the other. Women who have had ovarian cancer are also at a higher risk of developing breast cancer.

Breast Hyperplasia
Women who have had a breast biopsy with atypical hyperplasia (ductal or lobular), lobular carcinoma in situ, or cellular atypia also have an elevated risk for the development of breast cancer. 
 
Family History
Having a strong family history of breast cancer (either maternal or paternal) increases a woman's risk status. 

Breast Density
Breast density tends to decrease as a woman ages. As she gets older the dense ducts and lobules (glandular tissue) get replaced by fatty tissue.  High breast density, especially post-menopausally, is a risk factor for breast cancer. 

Hormones
The longer the breasts have been exposed to hormones, the higher the risk for developing breast cancer. Therefore, women who started menstruating before the age of 12 and stopped menstruating after 55 are at greater risk.  

Child-Birth
Not having children or having a first child over 30 also increases a woman's risk. Breast-feeding has been shown to reduce breast cancer risk.

Radiation Exposure
Prior radiation to the chest area, especially during the period between puberty and 30 years of age, increases the risk of breast cancer. 

Alcohol Use
Studies suggest that greater than 2 drinks a day increases breast cancer risk. 

Hereditary Breast Cancer
5-10% of all the breast cancers we see are likely due to an inherited mutation. BRCA 1 and BRCA 2 are two genes everyone has. Certain people are born with a mutation of one of these genes and this mutation significantly increases their likelihood of developing breast and ovarian cancer.  Some red flags in a person's personal or family history that would make us concerned about a genetic mutation are:

•  Breast cancer before the age of 50
• Ovarian cancer at any age
• Male breast cancer
• Bilateral breast cancer
• Both breast and ovarian cancer
• Relative with a BRCA 1 and BRCA 2  Mutation

To discuss your specific risk factors for breast cancer, call the St. John Health High Risk Breast Clinic at 1-888-440-0644.