What Causes Breast Cancer?

No one knows exactly what causes breast cancer. However, certain personal characteristics have been identified that may increase a woman's chance of developing breast cancer.

According to the New York State Department of Health, these risk factors include:

• Increasing age – as women get older their risk of developing breast cancer increases.
• Family history of breast cancer – women whose relatives have had breast cancer (especially at an early age) are more likely to get breast cancer.
• Breast cancer genes – about 5% to 10% of breast cancers are believed to be inherited.
• Personal history of breast cancer – a woman who has had cancer in one breast is more likely to develop it in the other breast or in remaining breast tissue.
• History of benign breast disease – women who have a history of certain types of non-cancerous tumors and cysts in their breasts are more likely to develop breast cancer.
• Hormonal factors – women who start their periods at a young age, start menopause at a late age, have their first child later in life, and have no full-term pregnancies may have an increased risk of developing breast cancer.

Although scientists are not sure, other studies indicate there may be additional, ancillary factors that could increase breast cancer risk, including:

• Taking birth control pills
• Exposure to certain chemicals in the environment
• Long-term use of hormone replacement therapy
• The use of alcoholic beverages
• Obesity and lack of physical activity

Myths: Research has shown that use of underarm deodorant or antiperspirants, underwire bras, induced abortions and silicone breast implants do not increase the risk of getting breast cancer.

Most women who develop breast cancer have no risk factors. Among women with average risk, breast cancer cannot be prevented.

However, there are things you can do to reduce your chances of getting breast cancer. Mammograms, breast self-examination, and examination of your breasts by your health care provider increase the chances that breast cancer will be diagnosed early.

Also, among women who have higher than average risk, certain drugs may be useful in preventing breast cancer. All women should discuss their risk and screening or prevention options with their health care provider.