Breast Cancer Treatment and Pregnancy (PDQ®)

As a National Cancer Institute (NCI)-designated Comprehensive Cancer Center, a core part of our mission is to educate patients and the community about cancer. The following summary is trusted information from the NCI.

General Information about Breast Cancer and Pregnancy

The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes, which have many smaller sections called lobules. The lobes and lobules are connected by thin tubes called ducts. Anatomy of the female breast. The nipple and areola are shown on the outside of the breast. The lymph nodes, lobes, lobules, ducts, and other parts of the inside of the breast are also shown.

Each breast also contains blood vessels and lymph vessels. The lymph vessels carry an almost colorless fluid called lymph. The lymph vessels lead to small, bean-shaped organs called lymph nodes that help the body fight infection and disease. Lymph nodes are found throughout the body. Clusters of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone, and in the chest.

In women who are pregnant or who have just given birth, breast cancer occurs most often between the ages of 32 and 38. Breast cancer occurs about once in every 3,000 pregnancies.

Breast cancer may cause any of the following signs and symptoms. Check with your doctor if any of the following problems occur:

  • A lump or thickening in or near the breast or in the underarm area.
  • A change in the size or shape of the breast.
  • A dimple or puckering in the skin of the breast.
  • A nipple turned inward into the breast.
  • Fluid, other than breast milk, from the nipple, especially if it's bloody.
  • Scaly, red, or swollen skin on the breast, nipple, or areola (the dark area of skin that is around the nipple).
  • Dimples in the breast that look like the skin of an orange, called peau d'orange.

Other conditions that are not breast cancer may cause these same symptoms.

Women who are pregnant, nursing, or have just given birth usually have tender, swollen breasts. This can make small lumps difficult to detect and may lead to delays in diagnosing breast cancer. Because of these delays, cancers are often found at a later stage in these women.

To detect breast cancer, pregnant and nursing women should examine their breasts themselves. Women should also receive clinical breast examinations during their routine prenatal and postnatal examinations.

If an abnormality is found, one or all of the following tests may be used:

  • Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.
  • Mammogram: An x-ray of the breast. A mammogram can be performed with little risk to the fetus. Mammograms in pregnant women may appear negative even though cancer is present. Mammography of the right breast.
  • Biopsy: The removal of cells or tissues by a pathologist so they can be viewed under a microscope to check for signs of cancer.

The prognosis (chance of recovery) and treatment options depend on the following:

  • The stage of the cancer (whether it is in the breast only or has spread to other places in the body).
  • The size of the tumor.
  • The type of breast cancer.
  • The age of the fetus.
  • Whether there are symptoms.
  • The patient's general health.

Stages of Breast Cancer

The process used to find out if the cancer has spread within the breast or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment.

Standard methods for giving imaging scans can be adjusted so that the fetus is exposed to less radiation. Tests to measure the level of hormones in the blood may also be used in the staging process.

The three ways that cancer spreads in the body are:

  • Through tissue. Cancer invades the surrounding normal tissue.
  • Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
  • Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

There are 2 types of breast carcinoma in situ:

Pea, peanut, walnut, and lime show tumor sizes.

In stage I, cancer has formed. Stage I is divided into stages IA and IB.

Stage II is divided into stages IIA and IIB.

  • In stage IIA:
    • no tumor is found in the breast, but cancer is found in the axillary lymph nodes (lymph nodes under the arm); or
    • the tumor is 2 centimeters or smaller and has spread to the axillary lymph nodes; or
    • the tumor is larger than 2 centimeters but not larger than 5 centimeters and has not spread to the axillary lymph nodes.
  • In stage IIB, the tumor is either:
    • larger than 2 centimeters but not larger than 5 centimeters and has spread to the axillary lymph nodes; or
    • larger than 5 centimeters but has not spread to the axillary lymph nodes.

In stage IIIA:

  • no tumor is found in the breast. Cancer is found in axillary lymph nodes that are attached to each other or to other structures, or cancer may be found in lymph nodes near the breastbone; or
  • the tumor is 2 centimeters or smaller. Cancer has spread to axillary lymph nodes that are attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone; or
  • the tumor is larger than 2 centimeters but not larger than 5 centimeters. Cancer has spread to axillary lymph nodes that are attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone; or
  • the tumor is larger than 5 centimeters. Cancer has spread to axillary lymph nodes that may be attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone.

In stage IIIB, the tumor may be any size and cancer:

Cancer that has spread to the skin of the breast is inflammatory breast cancer. See the section on Inflammatory Breast Cancer for more information.

In stage IIIC, there may be no sign of cancer in the breast or the tumor may be any size and may have spread to the chest wall and/or the skin of the breast. Also, cancer:

Cancer that has spread to the skin of the breast is inflammatory breast cancer. See the section on Inflammatory Breast Cancer for more information.

Stage IIIC breast cancer is divided into operable and inoperable stage IIIC.

In operable stage IIIC, the cancer:

  • is found in ten or more axillary lymph nodes; or
  • is found in lymph nodes below the collarbone; or
  • is found in axillary lymph nodes and in lymph nodes near the breastbone.

In inoperable stage IIIC breast cancer, the cancer has spread to the lymph nodes above the collarbone.

In stage IV, the cancer has spread to other organs of the body, most often the bones, lungs, liver, or brain.

Inflammatory Breast Cancer

In inflammatory breast cancer, cancer has spread to the skin of the breast and the breast looks red and swollen and feels warm. The redness and warmth occur because the cancer cells block the lymph vessels in the skin. The skin of the breast may also show the dimpled appearance called peau d'orange (like the skin of an orange). There may not be any lumps in the breast that can be felt. Inflammatory breast cancer may be stage IIIB, stage IIIC, or stage IV.

Inflammatory breast cancer of the left breast showing peau d'orange and inverted nipple.

Recurrent Breast Cancer

Recurrent breast cancer is cancer that has recurred (come back) after it has been treated. The cancer may come back in the breast, in the chest wall, or in other parts of the body.

Treatment Option Overview

Different types of treatment are available for patients with breast cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

For some patients, taking part in a clinical trial may be the best treatment choice. Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Clinical trials are taking place in many parts of the country. Information about clinical trials is available from the NCI Web site.

Most pregnant women with breast cancer have surgery to remove the breast. Some of the lymph nodes under the arm are usually taken out and looked at under a microscope to see if they contain cancer cells.

Types of surgery to remove the breast include:

Breast-conserving surgery, an operation to remove the cancer but not the breast itself, includes the following:

  • Lumpectomy: A surgical procedure to remove a tumor (lump) and a small amount of normal tissue around it. Most doctors also take out some of the lymph nodes under the arm.
  • Partial mastectomy: A surgical procedure to remove the part of the breast that contains cancer and some normal tissue around it. Some of the lymph nodes under the arm may also be removed for biopsy. This procedure is also called a segmental mastectomy.
Breast-conserving surgery. Dotted lines show the area containing the tumor that is removed and some of the lymph nodes that may be removed.

Even if the doctor removes all of the cancer that can be seen at the time of surgery, the patient may be given radiation therapy, chemotherapy, or hormone therapy after surgery to try to kill any cancer cells that may be left. Treatment given after surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Radiation therapy should not be given to pregnant women with early stage (stage I or II) breast cancer because it can harm the fetus. For women with late stage (stage III or IV) breast cancer, it should not be given during the first 3 months of pregnancy.

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Chemotherapy should not be given during the first 3 months of pregnancy. Chemotherapy given after this time does not usually harm the fetus but may cause early labor and low birth weight.

See Drugs Approved for Breast Cancer for more information.

This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the NCI Web site.

Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. Hormones are substances produced by glands in the body and circulated in the bloodstream. Some hormones can cause certain cancers to grow. If tests show that the cancer cells have places where hormones can attach (receptors), drugs, surgery, or radiation therapy is used to reduce the production of hormones or block them from working.

The effectiveness of hormone therapy, alone or combined with chemotherapy, in treating breast cancer in pregnant women is not yet known.

Because ending the pregnancy is not likely to improve the mother's chance of survival, it is not usually a treatment option.

Treatment Options by Stage

Early Stage Breast Cancer (Stage I and Stage II)

Treatment of early stage breast cancer (stage I and stage II) may be surgery followed by adjuvant therapy as follows:

Late Stage Breast Cancer (Stage III and Stage IV)

Treatment of late stage breast cancer (stage III and stage IV) may include the following:

Radiation therapy and chemotherapy should not be given during the first 3 months of pregnancy.

Other Considerations for Pregnancy and Breast Cancer

If surgery is planned, breast-feeding should be stopped to reduce blood flow in the breasts and make them smaller. Breast-feeding should also be stopped if chemotherapy is planned. Many anticancer drugs, especially cyclophosphamide and methotrexate, may occur in high levels in breast milk and may harm the nursing baby. Women receiving chemotherapy should not breast-feed. Stopping lactation does not improve survival of the mother.

Breast cancer cells do not seem to pass from the mother to the fetus.

Some doctors recommend that a woman wait 2 years after treatment for breast cancer before trying to have a baby, so that any early return of the cancer would be detected. This may affect a woman's decision to become pregnant. The fetus does not seem to be affected if the mother has previously had breast cancer.

The effects of treatment with high-dose chemotherapy and a bone marrow transplant, with or without radiation therapy, on later pregnancies are not known.

To Learn More About Breast Cancer and Pregnancy

For more information from the National Cancer Institute about breast cancer and pregnancy, see the following:

For general cancer information and other resources from the National Cancer Institute, see the following:



Cancer Care Services

Clinical Trials