Breast cancer starts when cells in the breast begin to grow out of control.

These cells usually form a tumor that can often be seen on an x-ray or felt as a lump. The tumor is malignant (cancer) if the cells can grow into (invade) surrounding tissues or spread (metastasize) to distant areas of the body. Breast cancer occurs almost entirely in women, but men can get breast cancer, too. Breast cancer can spread when the cancer cells get into the blood or lymph system and are carried to other parts of the body.

Treatment

There are several ways to treat breast cancer, depending on its type and stage:

Local treatments

Some treatments are called local therapies, meaning they treat the tumor without affecting the rest of the body. Types of local therapy used for breast cancer include:

• • Surgery
  • Radiation therapy

These treatments are more likely to be useful for earlier stage (less advanced) cancers, although they might also be used in some other situations.

Systemic treatments

Breast cancer can also be treated using drugs, which can be given by mouth or directly into the bloodstream. These are called systemic therapies because they can reach cancer cells anywhere in the body. Depending on the type of breast cancer, several different types of drugs might be used, including:

• • Chemotherapy
  • Hormone therapy
  • Targeted therapy

Many women will get more than one type of treatment for their cancer.