Breast Cancer, Female
Breast Cancer, Female

Breast Cancer, Female

The side view of the inside of a breast, showing lobules and milk ducts.

Breast cancer is a malignant growth of tissue (tumor) in the breast. Unlike noncancerous (benign) tumors, malignant tumors are cancerous and can spread to other parts of the body. The two most common types of breast cancer start in the milk ducts (ductal carcinoma) or in the lobules where milk is made in the breast (lobular carcinoma). Breast cancer is one of the most common types of cancer in women.

What are the causes?

The exact cause of female breast cancer is unknown.

What increases the risk?

The following factors may make you more likely to develop this condition:
  • Being older than 55 years of age.
  • Having a family history of breast cancer.
  • Starting menopause after age 55.
  • Starting your menstrual periods before age 12.
  • Having never been pregnant or having your first child after age 30.
  • Having never breastfed.
  • A personal history of:
    • Breast cancer.
    • Dense breast tissue.
    • Radiation exposure.
    • Having the BRCA1 and BRCA2 genes.
    • Having certain types of benign breast conditions.
    • Exposure to the drug DES, which was given to pregnant women from the 1940s to the 1970s.

Other risks include:
  • Using birth control pills.
  • Using hormone therapy after menopause.
  • Drinking more than one alcoholic drink a day.
  • Obesity.

What are the signs or symptoms?

Front and side view of a breast showing dimpling.

Symptoms of this condition include:
  • A painless lump or thickening in your breast.
  • Changes in the size or shape of your breast.
  • Breast skin changes, such as puckering or dimpling.
  • Nipple abnormalities, such as scaling, crustiness, redness, or pulling in (retraction).
  • Nipple discharge that is bloody or clear.

How is this diagnosed?

A comparison of breasts, showing the four stages of breast cancer.

This condition may be diagnosed by:
  • Taking your medical history and doing a physical exam. During the exam, your health care provider will feel the tissue around your breast and under your arms.
  • Taking a sample of nipple discharge. The sample will be examined under a microscope.
  • Performing imaging tests, such as breast X-rays (mammogram), ultrasound, or MRI.
  • Taking a tissue sample (biopsy) from the breast. The sample will be examined under a microscope to look for cancer cells.
  • Taking a sample from the lymph nodes near the affected breast (sentinel node biopsy).

Your cancer will be staged to determine its severity and extent. Staging is a careful attempt to find out the size of the tumor, whether the cancer has spread, and if so, to what parts of the body. Staging also includes testing your tumor for certain receptors, such as estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2). This will help your cancer care team decide on a treatment that will work best for you. You may need to have more tests to determine the stage of your cancer. Stages include the following:
  • Stage 0—The tumor has not spread to other breast tissue.
  • Stage 1 (I)—The cancer is only found in the breast or may be in the lymph nodes. The tumor may be up to ¾ inch (2 cm) wide.
  • Stage 2 (II)—The cancer has spread to nearby lymph nodes. The tumor may be up to 2 inches (5 cm) wide.
  • Stage 3 (III)—The cancer has spread to more distant lymph nodes. The tumor may be larger than 2 inches (5 cm) wide.
  • Stage 4 (IV)—The cancer has spread to other parts of the body, such as the bones, brain, liver, or lungs.

How is this treated?

Treatment for this condition depends on the type and stage of the breast cancer. It may be treated with:
  • Surgery. This may involve breast-conserving surgery (lumpectomy or partial mastectomy) in which only the part of the breast containing the cancer is removed. Some normal tissue surrounding this area may also be removed. In some cases, surgery may be done to remove the entire breast (mastectomy) and nipple. Lymph nodes may also be removed.
  • Radiation therapy, which uses high-energy rays to kill cancer cells.
  • Chemotherapy, which is the use of medicines to kill cancer cells.
  • Hormone therapy, which involves taking medicine to adjust the hormone levels in your body. You may take medicine to decrease your estrogen levels. This can help stop cancer cells from growing.
  • Targeted therapy, in which medicines are used to block the growth and spread of cancer cells. These medicines target a specific part of the cancer cell and usually cause fewer side effects than chemotherapy. Targeted therapy may be used alone or in combination with chemotherapy.
  • Immunotherapy, which is the use of medicines to boost the immune system to recognize and destroy cancer cells more effectively.
  • A combination of surgery, radiation, chemotherapy, or hormone therapy may be needed to treat breast cancer.

Follow these instructions at home:

  • Take over-the-counter and prescription medicines only as told by your health care provider.
  • Eat a healthy diet. A healthy diet includes lots of fruits and vegetables, low-fat dairy products, lean meats, and fiber.
    • Make sure half your plate is filled with fruits or vegetables.
    • Choose high-fiber foods such as whole-grain breads and cereals.
  • Consider joining a support group. This may help you cope with the stress of having breast cancer.
  • Talk to your health care team about exercise and physical activity. The right exercise program can:
    • Help prevent or reduce symptoms such as fatigue or depression.
    • Improve overall health and survival rates.
  • Keep all follow-up visits. This is important.

Where to find more information

Contact a health care provider if:

  • You have a sudden increase in pain.
  • You have any symptoms or changes that concern you.
  • You lose weight without trying.
  • You notice a new lump in either breast or under your arm.
  • You develop swelling in either arm or hand.
  • You have a fever.
  • You notice new fatigue or weakness.

Get help right away if:

  • You have chest pain or trouble breathing.

These symptoms may be an emergency. Get help right away. Call 911.
  • Do not wait to see if the symptoms will go away.
  • Do not drive yourself to the hospital.


  • Breast cancer is a malignant growth of tissue (tumor) in the breast.
  • Your cancer will be staged to determine its severity and extent.
  • Treatment for this condition depends on the type and stage of the breast cancer.

This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.