Breast Cancer Risk Factors

Breast cancers develop when breast cells acquire genetic damage that interfere with their normal function, leading to uncontrolled cellular division (i.e. tumor growth). There are a number of things that can cause genetic damage and/or that can over-stimulate breast cell division. These are considered risk factors for breast cancer.

One single risk factor is unlikely to cause a cancer to develop, but several risk factors interacting with one another may contribute to the process. Having these risk factors does not necessarily mean that you will develop breast cancer, and you can still get breast cancer even if you do not have the risk factors. In other words, every woman has some degree of risk for breast cancer. It is just that some women have a greater risk than others, depending upon their particular risk factors.

Being a woman and aging are the most significant risk factors for breast cancer. In fact, more than 70 percent of all women who develop breast cancer have no identifiable risk factors besides their sex and age. Additional risk factors are listed below.

 

Risk Factors

  • Age (greater risk after age 50)
  • Family history (greater risk associated with multiple diagnoses in the family, early ages of diagnosis, bilateral disease and male breast cancers)
  • Inherited mutations in certain genes (i.e. BRCA1 and BRCA2)
  • Prior breast cancer diagnosis (same or opposite breast)
  • First menstrual period at a young age (before age 12)
  • Nullparity (no children) or first full-term pregnancy after age 30
  • Late menopause (after age 55)
  • High dose ionizing radiation exposure to the chest (i.e. for treatment of Hodgkin's disease, acne, etc.), particularly before the age of 30
  • Biopsy-proven breast atypia (abnormal cells) or LCIS (lobular carcinoma in situ)
  • Obesity, particularly after menopause
  • Certain body types (i.e. apple-shaped women)
  • Diabetes
  • Prolonged exposure to hormone replacement therapy
  • Excessive alcohol intake (greater than nine drinks per week), particularly before age 30
  • Physical inactivity, particularly before age 40
  • Breast density
  • Environmental hazards

 

African-American Women and Breast Cancer

Recent studies suggest that the incidence of breast cancer among African-American women is lower than the incidence among Caucasian women but that a greater proportion of African-American women who do develop breast cancer do so at a younger age.

African-American women diagnosed with breast cancer are more likely than Caucasian women to die from their disease. This difference in survival rates is due, in part, to the fact that African American women undergo fewer screening mammograms, as compared to Caucasian women, which means that their cancers are more likely to be diagnosed at a later stage when treatment is more difficult and survival rates are lower. The difference in survival rates also appears to reflect a tendency for African American women to have more aggressive breast cancers, stage for stage.

 

Male Breast Cancer and Men at Risk

Male breast cancer is relatively rare, with approximately 1600 cases diagnosed in the United States each year. Men with breast cancer are typically diagnosed at a later age than women (average age of diagnosis is 65). The first symptom that most men notice is a painless lump. Additional symptoms might include nipple discharge (possibly bloody), nipple retraction and skin ulceration. For a variety of reasons, men may not seek early treatment for breast cancer. Men are unlikely to examine their breasts on a regular basis and, when they notice symptoms, they are more likely to delay seeing a physician.

Diagnosis and treatment of male breast cancer is similar to that for women. Surgical treatment followed, in some cases, by radiation, chemotherapy and/or hormone therapy. Decisions regarding post-surgical treatment are made on a case by case basis and depend on individual factors, including age. As with women, male breast cancer can generally be cured and/or controlled if it is detected early and promptly treated.

A man's risk of developing breast cancer increases with age. Additional risk factors for male breast cancer include:

  • Family history of breast cancer (male or female)
  • Inherited mutations in certain genes (primarily BRCA2)
  • Hyper-estrogenic conditions (e.g., Klinefelter's syndrome)
  • Radiation exposure to the chest (i.e. for Hodgkin's disease)
  • Excessive alcohol consumption
  • Liver disease
  • Estrogen administration
  • Obesity

 

Genetic Testing

Women with a strong family history of breast cancer have an increased risk of developing the disease. Characteristics of a strong family history include multiple first or second degree relatives diagnosed with the disease (sisters, mothers, aunts, grandmothers), early ages of diagnosis (before age 50), bilateral disease, and male breast cancers. Some particularly strong family histories of breast and ovarian cancer have been associated with inherited mutations in the breast cancer genes (BRCA1 and BRCA2). Mutations in these genes account for a relatively small proportion of all breast cancers, but the risk of developing breast or ovarian cancer is very high for women who carry mutations.

For women who have a strong family history of breast cancer and/or for women who have a personal history of breast cancer diagnosed at a young age, identifying a BRCA gene mutation through genetic testing can have a major impact on how they manage their health. Genetic counseling and BRCA gene testing are available at the Saul and Joyce Brandman Breast Center - A Project of Women's Guild as part of the Wasserman Breast Cancer Risk Reduction Program or through the GenRISK Adult Genetics Program.

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