Health Topics

Ask the Expert: Breast Cancer Risk Factors, Am I at Risk?

More than ever before, women are interested in being pro-active about reducing the risk of breast cancer. At the center of this change is our growing concern and understanding of breast cancer, the second most common form of cancer among women in the United States.

What is Breast Cancer?

Cells in the body normally divide (reproduce) only when new cells are needed. Sometimes cells will divide for no reason, creating a mass of tissue called a tumor. Tumors can be benign (not cancerous) or malignant (cancerous).

In breast cancer, as well as in some other cancers, a tissue cell becomes abnormal and reproduces without control or order, forming a malignant tumor. Cancer cells can break off from the tumor, travel to other parts of the body, and form new tumors. This process is called metastasis. Metastasis is a late stage of cancer.

Am I at Risk for Developing Breast Cancer?

If you are a woman, you are at risk. (Men can also develop breast cancer, but this is rare.) You may be more likely to develop breast cancer if you have one or more risk factors, but risk factors do not cause breast cancer. However, not having a risk factor does not mean that you will not get breast cancer.

In many cases, it’s not known why a woman develops breast cancer. In fact, 70 percent of all women with breast cancer have no known risk factor.

What are the risk factors of breast cancer?

A risk factor is anything that increases a person’s chance of getting a disease. Different cancers have different risk factors.

Significantly higher risk

History of previous cancer in one breast, especially if it occurred before menopause, increases a woman’s risk of developing a new breast cancer unrelated to the first one. This is different than a recurrence of the previous breast cancer.

Genetics also plays a role. Carriers of either of two familial breast cancer genes called BRCA1 or BRCA2 are at higher risk. Ten percent of women are carriers of these genes. Also, 5-10 percent of all breast cancers are thought to be from either gene. In addition, the risk of getting breast cancer is up to 85 percent in a woman’s lifetime if she has inherited these genes.

Moderately higher risk

  • Getting older. Your risk for breast cancer increases as you age. About 77 percent of women diagnosed with breast cancer each year are over age 50, and almost half are age 65 and older. Consider this: In women 40 to 49 years of age, there is a one in 66 risk of developing breast cancer. In the 50 to 59 age group, that risk increases to one in 40.
  • Direct family history. Having a mother, sister, or daughter (a "first-degree relative") who has breast cancer puts you at higher risk for the disease. The risk is even greater if your relative developed breast cancer before menopause and had cancer in both breasts. Having one first-degree relative with breast cancer approximately doubles a woman’s risk. Having two first-degree relatives with breast cancer increases her risk five-fold. Having a male blood relative with breast cancer may also increase a woman’s risk of the disease.
  • Breast lesions. These include multiple papillomatosis, atypical ductal hyperplasia, and lobular carcinoma in situ.

Slightly higher risk

  • Distant family history. This refers to breast cancer in more distant relatives such as aunts, grandmothers, and cousins.
  • Large cysts in the breast. Large cysts increase your risk, especially if accompanied by early atypical hyperplasia (abnormal cell changes in the breast). A previous breast biopsy result of atypical hyperplasia increases a woman’s breast cancer risk by four to five times
  • Age at childbirth. Having your first child after age 30 or never having children puts you at higher risk.
  • Early menstruation. Your risk increases if you got your period before age 12.
  • Late menopause. If you begin menopause after age 55, your risk of diagnosis increases (but overall death rates are lower with late menopause).
  • Weight. Being overweight (especially in the upper body), with excess caloric and fat intake, increases your risk, especially after menopause.
  • Excessive radiation. This is especially true for women who were given radiation for postpartum mastitis, received prolonged fluoroscopic X-rays for tuberculosis, or who were exposed to a large amount of radiation before age 30 (usually as a treatment for cancers such as lymphoma or Hodgkin’s disease).
  • Other cancer in the family. A family history of cancer of the ovaries, cervix, uterus, or colon increases your risk.
  • Heritage. Female descendents of Eastern and Central European Jews (Ashkenazi) are at increased risk.
  • Race. Breast cancer occurs more frequently in Caucasian women than in Hispanic, Asian, or African-American women.
  • Alcohol. The use of alcohol is linked to increased risk of developing breast cancer. Compared with nondrinkers, women who consume one alcoholic drink a day have a 10 percent increase in risk, and those who have two or three drinks daily have about 20 percent to 30 percent higher risk than women who drink no alcohol. Alcohol is also known to increase the risk of developing cancers of the mouth, throat, and esophagus.
  • Menopausal hormone therapy. Combination estrogen-progestin hormones taken for more than 5 years increases the risk of being diagnosed with breast cancer by one extra case of breast cancer per 1,000 women.

Low risk

  • Pregnancy before age 18
  • Breastfeeding
  • Early onset of menopause
  • Surgical removal of the ovaries before age 40

Factors not related to breast cancer

  • Fibrocystic breast changes
  • Multiple pregnancies
  • Coffee or caffeine intake
  • Antiperspirants
  • Underwire bras
  • Abortion
  • Breast implants

There are other factors that may affect your risk for breast cancer, but medical research has not yet determined the exact role they play. Scientists are investigating the effects of high-fat diets, lack of exercise, and environmental pollutions as well as certain viruses that may increase breast cancer risk.

How can I Protect Myself From Breast Cancer?

  • Get a mammogram:
    • Annual mammogram start at age 45 and personalized.
    • Some women can wait until age 50 to begin screening mammograms and have them done every 2 years.
    • High risk women need more intensive screening.
  • Avoid weight gain, lack of exercise and tobacco and/or excessive alcohol use
  • Get adequate amounts of vitamin D3 and calcium and folic acid
  • In the future, we hope to have vaccines to reduce the risk of breast cancer.

Where can I learn more?

NCI Cancer Information Hotline
800.422.6237 (800.4.CANCER)
TTY: 800.332.8615

American Cancer Society
800.ACS.2345 (800.227.2345)
TTY: 866.228.4327

Susan G. Komen Breast Cancer Foundation
5005 LBJ Freeway, Suite 250
Dallas, Texas 75244
Fax: 972.855.1605
Helpline: 800.I’M AWARE (800.462.9273)

For more information, visit Cleveland Clinic’s Center for Specialized Women’s Health.