Breast Cancer: Causes & Risk Factors

Health Monitor Staff
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At this time, scientists are not certain what causes breast cancer. However, they do know that both family history and environmental factors play a role. Up to 10% of breast cancers are caused by genetic abnormalities inherited from either parent. The remaining breast cancers are due to genetic abnormalities that happen as a result of aging or because of exposure to various substances. The impact of chemical exposure is under intense investigation. Therefore, whatever you do, it's important not to get caught up in a blame game. Guilt is not helpful in the battle against breast cancer.

Common risk factors
Understanding your own particular risk factors may encourage you keep up with routine screenings and provide the opportunity for early detection. Here are some of the known breast cancer risk factors:

Heredity: A woman's risk of breast cancer approximately doubles if she has a first-degree relative (mother, sister or daughter) who has been diagnosed with breast cancer.

Age: Your chance of developing breast cancer rises as you get older. For example, if you are 20, your risk of getting breast cancer in the next 10 years is one in 2,000. By age 40, your risk of getting breast cancer in the next 10 years is one in 69. And based on current rates, 12.2% of women born in the United States—approximately 1 in 8—will develop breast cancer at some time in their lives, assuming they live to age 80.

Although this 1 in 8 figure may sound scary, it's important to remember that based on these same statistics, the chances that you will never get breast cancer is 87.8% (expressed as "7 in 8")! It's also important to know that thanks to earlier detection and more effective treatment options, fewer than 20% of women diagnosed will die of the disease—early detection being critical for increased survival rates.

Reproductive history: Your menstrual cycle and childbearing history can play a role in your risk of developing breast cancer. Women who start having periods before the age of 12 are at a higher risk, as are women who undergo menopause after age 55. Women who have their first full-term pregnancy after age 30 and women who never have a full-term pregnancy are at higher risk for breast cancer than those who give birth earlier in life. Also related to menopause is the use of use of hormone replacement therapy, commonly referred to as HRT. This use of drugs is considered to be a risk factor as well.

Race: White women are slightly more likely to develop breast cancer than African Americans. However, white women are less likely to die of it. Doctors believe that African American women tend to have more aggressive tumors, but they are unsure why. Women of other ethnic backgrounds—Asian, Hispanic and Native American—have a lower risk of developing and dying from breast cancer than white women and African American women.

May 2013