Breast Cancer Risk Factors

If you're a woman, you're at risk for breast cancer.  Unfortunately, the incidence of breast cancer keeps growing.  This year 211,240 new cases of invasive breast cancer will be diagnosed in the United States with 4,000 in the state of Wisconsin.  Approximately, 40,410 women in the United States are expected to die from this disease with more than 700 deaths in Wisconsin. Our mothers, daughter, sister, or friends chance of getting breast cancer is now 1 in 7.

While it is impossible to know who will get breast cancer and who will not, most cases can be linked to a handful of known risk factors.

Risk Factors

What puts you at risk for breast cancer?

  • Gender – Although breast cancer occasionally afflicts men, roughly 99 percent of all cases occur in women.
  • Age – The risk for breast cancer arises significantly after the age of 40.  An estimated 75 percent of breast cancer cases are found in women over 50.
  • Personal history – If you have had breast cancer before, you are five times more likely to develop it again in the opposite breast.
  • Family history – If your mother or sister has had breast cancer – especially if they developed it before menopause – your own risk increases.
  • Early onset of menstruation – If you were younger than 12 when you started menstruating, you may be more susceptible to developing breast cancer.
  • Late menopause – The later a woman goes through menopause, the more likely she is to develop breast cancer.  This may be due to prolonged exposure to the hormone estrogen, which has been implicated in hormone-dependent cancers such as breast cancer.
  • Not having had children, not having breast-fed, or having a first child after the age of 30 – Excess estrogen may play a role.

Even if none – or few – of these risk factors apply to you, don't assume you are safe.  In 70 percent of breast cancer cases, the patients have no or few identifiable risk factors.  The medical community still does not know exactly what triggers breast cancer, or why some women with few risk factors get it, while other women with several risk factors don't.   No matter how high or low your risk of developing breast cancer is, your best defense is to find breast cancer early. 

 Early Detection

  • Monthly breast self-exam – All women need to check their breasts for lumps, thickness, or other changes.  By examining your breasts regularly, you will know how your breasts normally feel.  If a change should happen in your breasts, you will be able to identify it and let your doctor know.
  • Mammogram – Have a mammogram every year if you are age 40 or older (earlier if there is a family history of breast cancer).
  • Clinical breast examination – A regular breast exam performed by a medical professional is recommended at least every three years.

 Statistics source: American Cancer Society