Breast cancer

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Breast cancer happens when cells in your breast grow abnormally and out of control. The cancer cells can spread to other parts of your body.

You're more likely to get breast cancer as you get older.

Breast cancer can occur in people who don't identify as female but have breasts.




The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.