What is breast cancer?

Breast cancer occurs when abnormal cells grow out of control in one or both breasts. These cancer cells can spread (metastasize) to nearby tissues and form a mass, called a tumor. The cells can spread within the breast, to nearby lymph nodes and other tissues, and to other parts of the body.

The most common type of breast cancer starts in the ducts of the breast. It's called ductal carcinoma.

Breast cancer can occur in anyone. And it can occur even after a breast reduction or a mastectomy.

The first sign of breast cancer is often a painless lump. But early breast cancer is often found on a mammogram before a lump can be felt.

Other symptoms of breast cancer may not appear until the cancer is more advanced. These include:

• A thickening in the breast or armpit.
• A change in the size or shape of the breast.
• Changes in the skin of the breast, such as a dimple or skin that looks like an orange peel.
• A change in the nipple, such as scaling of the skin or a nipple that turns in.
• A green or bloody fluid that comes from the nipple.
• A change in the color or feel of the skin around the nipple (areola).

Symptoms such as changes in the skin of the breast or the nipple may be a sign of inflammatory breast cancer.

Depending on your age and risk factors, the doctor may recommend that you have an ultrasound or a mammogram. A mammogram can often find a lump that is too small to feel.

During a regular physical exam, your doctor can check your breasts for lumps or changes. You also may find a lump on your own.

If there are concerns, the doctor will check to see if there is cancer by looking at a sample of cells (biopsy). The results of the biopsy help your doctor know if you have cancer and what type of cancer it is.

You may have other tests to find out the stage of the cancer. The stage is a way for doctors to describe how far the cancer has spread.

Your doctor may combine treatments. This is a common way to treat breast cancer. Treatment depends on what type and stage of cancer you have. You may have:

• Surgery to remove the cancer.
• Radiation. This uses high-dose X-rays to kill cancer cells and shrink tumors.
• Chemotherapy. This uses medicine to kill cancer cells.
• Hormone therapy. This uses medicines such as tamoxifen. It limits the effect of the hormone estrogen. This hormone can help some types of breast cancer cells to grow.
• Targeted therapy. This uses medicines such as trastuzumab (Herceptin) to help keep cancer from growing or spreading.
• Immunotherapy. This uses medicines like pembrolizumab to help your immune system fight cancer.

There are things you can do at home to help manage the symptoms of cancer and the side effects of treatment. Talk to your doctor about ways to care for yourself at home. Your doctor may give you medicines that can help. If your doctor has given you instructions or medicines to treat symptoms or side effects, be sure to use them.

Healthy habits such as eating right and getting enough sleep and exercise can help.