Breast cancer is cancer that starts in the tissues of the breast.
There are two main types of breast cancer:
• Ductal carcinoma starts in the tubes (ducts) that carry milk from the breast to the nipple. Most breast cancers are of this type.
• Lobular carcinoma starts in the parts of the breast, called lobules, which produce milk.
In rare cases, other kinds of breast cancer can start in other areas of the breast.
Breast cancer risk factors are things that increase the chance that you could develop breast cancer:
• Some risk factors you can control, such as drinking alcohol. Others, such as family history, you cannot control.
• The more risk factors you have, the more your risk increases. But, it does not mean you will develop cancer. Many women who develop breast cancer do not have any known risk factors or a family history.
• Understanding your risk factors can help you take steps to lower your risk.
Some women are at higher risk for breast cancer because of certain genetic markers or variants that may be passed down from their parents.
• Genes known as BRCA1 or BRCA2 are responsible for most cases of inherited breast cancers.
• A screening tool with questions about your family’s history as well as yours can help your health care provider whether you are at risk for carrying these genes.
• If you are at high risk, a blood test to see if you carry the genes.
• Certain other genes may lead to an increased risk of breast cancer.
Breast implants, using antiperspirants, and wearing underwire bras do not increase the risk for breast cancer. There is also no evidence of a direct link between breast cancer and pesticides.