Breast cancer develops when normal cells in the breast grow and multiply abnormally. This process can lead to a tumor or an area of firmness in the breast that you can feel, or it may be seen on imaging tests. Sometimes these changes are found by accident, such as when you’ve had a procedure for an unrelated reason. But usually a screening test such as mammography or a physical exam detects them.

In many cases, breast tumors are benign (noncancerous), which means they can’t spread and aren’t directly life threatening. In malignant (cancerous) tumors, the cancer cells divide out of control. Those cells can invade nearby tissues and potentially metastasize, or spread, to other parts of the body.

A small percentage of breast cancers are inherited, which means they are passed down within families, or linked to mutations in the genes. People with hereditary breast cancer may be at risk of developing other cancers — including ovarian cancer in particular. For women who have an increased risk based on genetic or other factors, we offer surveillance and screening programs.

The stage of your disease will determine your treatment. You may have:

Your treatment will vary based on how advanced your disease is and whether your tumor might respond to targeted therapies. If you have certain types of surgery, you may wish to consider breast reconstruction.

At any point in your care you may also be eligible for a clinical trial exploring a new treatment option or approach.

Although it’s much less common, breast cancer can also occur in men. Learn more about male breast cancer.

Symptoms of Breast Cancer

Many breast cancers are discovered through routine screening of people who have no symptoms or outward evidence of disease. There are symptoms that could be suspicious, however. You should see a doctor right away if any of the following occur:

  • a physical change in the breast, such as a lump, a thickening, or a change in its size or shape
  • changes in the nipple such as retraction (pulling in of the nipple) or fluid that comes out on its own without squeezing
  • an inflammatory change, such as redness or hardening of the breast
  • a lump in the underarm lymph nodes

Very rarely, the first evidence of breast cancer is a lump, pain, or discomfort elsewhere in the body.

It is always possible that even though your breast feels normal, a screening test will show an abnormality. These tests are designed to find hidden disease.