Breast cancer occurs when the DNA in a breast tissue cell is damaged, and the cell reproduces too rapidly.  But what causes this DNA damage?  Scientists are still researching to find the answer, so no one truly understands the causes of breast cancer.  We do know that exposure to estrogen can be a factor in who gets breast cancer.

As I explained in an earlier article, risk factors are not the same as causes.  They are conditions that are known to be more common in people who get breast cancer.  Because many women who have breast cancer have no known risk factors and women who have several risk factors may never develop breast cancer, a risk factor is not a cause.  Nevertheless, scientists have noticed that many of the risk factors for breast cancer are related to estrogen exposure and hormone regulation.  Some of these risk factors are not easily controlled by choice.  These include early age for first menstruation, no childbirth, childbirth after age 30, and late age for menopause.

However, there are other factors that affect hormones that may have a connection to breast cancer.  Some are definitely connected, and some are still under study or controversial.  Here are some possible risk factors that you can control.

Hormone Replacement Therapy (HRT)  Many women have used estrogen or estrogen/progesterone pills to relieve menopausal symptoms.  In fact, at one time HRT was believed to reduce a woman's risk of heart disease and other problems of aging.  Then in 2002, a large study by the Woman's Health Initiative was stopped because it turned out that the group of women receiving HRT had a higher rate of breast cancer and no benefits to heart health.  Subsequent studies have confirmed these original findings.

Although some people argue that today's HRT uses smaller doses of hormones than earlier versions, it makes sense that any hormone strong enough to reduce menopausal symptoms might also be raising the risk of breast cancer.  Women who have early medical menopause and those who have severe hot flashes or other troublesome menopausal symptoms should discuss with their doctors how much risk they would incur by taking HRT and then decide the best balance of risk and benefits for them.

Birth control pills: Birth control pill users may have a slightly higher risk of breast cancer, but studies into birth control pills and cancer are contradictory-perhaps because there are so many different formulations of the pill.  After stopping birth control pills, the risk decreases over time and by 10 years after stopping the pills, users and non-users have the same risk.  A woman who has other risk factors for breast cancer will want to discuss with her doctor whether birth control pills are right for her.  Because pregnancy has its own set of health risks, the pill may still be the best option for many women, especially for young women who are at low risk for breast cancer because of their age.