Breast Cancer Treatment During Pregnancy (PDQ®)–Patient Version
General Information About Breast Cancer Treatment During Pregnancy
- Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
- Sometimes breast cancer occurs in women who are pregnant or have just given birth.
- Signs of breast cancer include a lump or change in the breast.
- It may be difficult to detect (find) breast cancer early in pregnant or nursing women.
- Breast exams should be part of prenatal and postnatal care.
- Tests that examine the breasts are used to detect (find) and diagnose breast cancer.
- If cancer is found, tests are done to study the cancer cells.
- Certain factors affect prognosis (chance of recovery) and treatment options.
Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes. Each lobe has many smaller sections called lobules. Lobules end in dozens of tiny bulbs that can make milk. The lobes, lobules, and bulbs are linked by thin tubes called ducts.
Each breast also has blood vessels and lymph vessels. The lymph vessels carry an almost colorless, watery fluid called lymph. Lymph vessels carry lymph between lymph nodes. Lymph nodes are small, bean-shaped structures found throughout the body. They filter lymph and store white blood cells that help fight infection and disease. Groups of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone, and in the chest.
Sometimes breast cancer occurs in women who are pregnant or have just given birth.
Breast cancer occurs about once in every 3,000 pregnancies. It occurs most often in women aged 32 to 38 years. Because many women are choosing to delay having children, it is likely that the number of new cases of breast cancer during pregnancy will increase.
Signs of breast cancer include a lump or change in the breast.
- 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 around the nipple).
- Dimples in the breast that look like the skin of an orange, called peau d’orange.
It may be difficult to detect (find) breast cancer early in pregnant or nursing women.
The breasts usually get larger, tender, or lumpy in women who are pregnant, nursing, or have just given birth. This occurs because of normal hormone changes that take place during pregnancy. These changes can make small lumps difficult to detect. The breasts may also become denser. It is more difficult to detect breast cancer in women with dense breasts using mammography. Because these breast changes can delay diagnosis, breast cancer is often found at a later stage in these women.
Breast exams should be part of prenatal and postnatal care.
To detect breast cancer, pregnant and nursing women should examine their breasts themselves. Women should also receive clinical breast exams during their regular prenatal and postnatal check-ups. Talk to your doctor if you notice any changes in your breasts that you do not expect or that worry you.
Tests that examine the breasts are used to detect (find) and diagnose breast cancer.
The following tests and procedures may be used:
- Physical exam and history : An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
- Clinical breast exam (CBE): An exam of the breast by a doctor or other health professional. The doctor will carefully feel the breasts and under the arms for lumps or anything else that seems unusual.
- 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. The picture can be printed to look at later.
- Mammogram : An x-ray of the breast. A mammogram can be done with little risk to the unborn baby. Mammograms in pregnant women may appear negative even though cancer is present.
Biopsy : The removal
of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. If a lump in the breast is
found, a biopsy may be done.
There are four types of breast biopsies:
If cancer is found, tests are done to study the cancer cells.
Decisions about the best treatment are based on the results of these tests and the age of the unborn baby. The tests give information about:
- How quickly the cancer may grow.
- How likely it is that the cancer will spread to other parts of the body.
- How well certain treatments might work.
- How likely the cancer is to recur (come back).
Tests may include the following:
- Estrogen and progesterone receptor test : A test to measure the amount of estrogen and progesterone (hormones) receptors in cancer tissue. If there are more estrogen or progesterone receptors than normal, the cancer is called estrogen receptor positive or progesterone receptor positive. This type of breast cancer may grow more quickly. The test results show whether treatment to block estrogen and progesterone given after the baby is born may stop the cancer from growing.
- Human epidermal growth factor type 2 receptor (HER2/neu) test : A laboratory test to measure how many HER2/neu genes there are and how much HER2/neu protein is made in a sample of tissue. If there are more HER2/neu genes or higher levels of HER2/neu protein than normal, the cancer is called HER2/neu positive. This type of breast cancer may grow more quickly and is more likely to spread to other parts of the body. The cancer may be treated with drugs that target the HER2/neu protein, such as trastuzumab and pertuzumab, after the baby is born.
Multigene tests: Tests in which samples of tissue are studied to look at the activity of many genes at the same time. These tests may help predict whether cancer will spread to other parts of the body or recur (come back).
- Oncotype DX : This test helps predict whether stage I or stage II breast cancer that is estrogen receptor positive and node-negative will spread to other parts of the body. If the risk of the cancer spreading is high, chemotherapy may be given to lower the risk.
- MammaPrint : This test helps predict whether stage I or stage II breast cancer that is node-negative will spread to other parts of the body. If the risk of the cancer spreading is high, chemotherapy may be given to lower the risk.
Certain factors affect prognosis (chance of recovery) and treatment options.
Stages of Breast Cancer
- After breast cancer has been diagnosed, tests are done to find out if cancer cells have spread within the breast or to other parts of the body.
- There are three ways that cancer spreads in the body.
- Cancer may spread from where it began to other parts of the body.
- The following stages are used for breast cancer:
- Stage 0 (carcinoma in situ)
- Stage I
- Stage II
- Stage IIIA
- Stage IIIB
- Stage IIIC
- Stage IV
After breast cancer has been diagnosed, tests are done to find out if cancer cells have spread within the breast or to other parts of the body.
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.
Some procedures may expose the unborn baby to harmful radiation or dyes. These procedures are done only if absolutely necessary. Certain actions can be taken to expose the unborn baby to as little radiation as possible, such as the use of a lead-lined shield to cover the abdomen.
- Chest x-ray : An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
- Bone scan : A procedure to check if there are rapidly dividing cells, such as cancer cells, in the bone. A very small amount of radioactive material is injected into a vein and travels through the bloodstream. The radioactive material collects in bones with cancer and is detected by a scanner.
- Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs, such as the liver, and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body, such as the brain. This procedure is also called nuclear magnetic resonance imaging (NMRI).
There are three ways that cancer spreads in the body.
- Tissue. The cancer spreads from where it began by growing into nearby areas.
- Lymph system. The cancer spreads from where it began by getting into the lymph system. The cancer travels through the lymph vessels to other parts of the body.
- Blood. The cancer spreads from where it began by getting into the blood. The cancer travels through the blood vessels to other parts of the body.
Cancer may spread from where it began to other parts of the body.
The metastatic tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bone, the cancer cells in the bone are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.
The following stages are used for breast cancer:
This section describes the stages of breast cancer. The breast cancer stage is based on the results of testing that is done on the tumor and lymph nodes removed during surgery and other tests.
Stage 0 (carcinoma in situ)
There are 3 types of breast carcinoma in situ:
- Ductal carcinoma in situ (DCIS) is a noninvasive condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, DCIS may become invasive cancer and spread to other tissues. At this time, there is no way to know which lesions could become invasive.
- Lobular carcinoma in situ (LCIS) is a condition in which abnormal cells are found in the lobules of the breast. This condition seldom becomes invasive cancer. However, having LCIS in one breast increases the risk of developing breast cancer in either breast.
- Paget disease of the nipple is a condition in which abnormal cells are found in the nipple only.
Stage II is divided into stages IIA and IIB.
- In stage IIA:
- no tumor is found in the breast or the tumor is 2 centimeters or smaller. Cancer (larger than 2 millimeters) is found in 1 to 3 axillary lymph nodes or in the lymph nodes near the breastbone (found during a sentinel lymph node biopsy); or
- the tumor is larger than 2 centimeters but not larger than 5 centimeters. Cancer has not spread to lymph nodes.
- In stage IIB, the tumor is:
- larger than 2 centimeters but not larger than 5 centimeters. Small clusters of breast cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes; or
- larger than 2 centimeters but not larger than 5 centimeters. Cancer has spread to 1 to 3 axillary lymph nodes or to the lymph nodes near the breastbone (found during a sentinel lymph node biopsy); or
- larger than 5 centimeters. Cancer has not spread to lymph nodes.
In stage IIIA:
- no tumor is found in the breast or the tumor may be any size. Cancer is found in 4 to 9 axillary lymph nodes or in lymph nodes near the breastbone (found during imaging tests or a physical exam); or
- the tumor is larger than 5 centimeters. Small clusters of breast cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes; or
- the tumor is larger than 5 centimeters. Cancer has spread to 1 to 3 axillary lymph nodes or to lymph nodes near the breastbone (found during a sentinel lymph node biopsy).
Cancer that has spread to the skin of the breast may also be inflammatory breast cancer.
In stage IIIC, no tumor is found in the breast or the tumor may be any size. Cancer may have spread to the skin of the breast and caused swelling or an ulcer and/or has spread to the chest wall. Also, cancer has spread to:
Cancer that has spread to the skin of the breast may also be inflammatory breast cancer.
Treatment Option Overview
- Treatment options for pregnant women depend on the stage of the disease and the age of the unborn baby.
- Three types of standard treatment are used:
- Radiation therapy
- Ending the pregnancy does not seem to improve the mother’s chance of survival.
- Treatment for breast cancer may cause side effects.
Treatment options for pregnant women depend on the stage of the disease and the age of the unborn baby.
Three types of standard treatment are used:
Most pregnant women with breast cancer have surgery to remove the breast. Some of the lymph nodes under the arm may be removed so they can be checked under a microscope by a pathologist for signs of cancer.
Types of surgery to remove the cancer include:
- Modified radical mastectomy: Surgery to remove the whole breast that has cancer, many of the lymph nodes under the arm, the lining over the chest muscles, and sometimes, part of the chest wall muscles. This type of surgery is most common in pregnant women.
- Breast-conserving surgery: Surgery to remove the cancer and some normal tissue around it, but not the breast itself. Part of the chest wall lining may also be removed if the cancer is near it. This type of surgery may also be called lumpectomy, partial mastectomy, segmental mastectomy, quadrantectomy, or breast-sparing surgery.
After the doctor removes all of the cancer that can be seen at the time of surgery, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that are left. For pregnant women with early-stage breast cancer, radiation therapy and hormone therapy are given after the baby is born. Treatment given after surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.
The way the radiation therapy is given depends on the type and stage of the cancer being treated.
External radiation therapy may be given to pregnant women with early stage (stage I or II) breast cancer after the baby is born. Women with late stage (stage III or IV) breast cancer may be given external radiation therapy after the first 3 months of pregnancy or, if possible, radiation therapy is delayed until after the baby is born.
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. Systemic chemotherapy is used to treat breast cancer during pregnancy.
Chemotherapy is usually not given during the first 3 months of pregnancy. Chemotherapy given after this time does not usually harm the unborn baby but may cause early labor or low birth weight.
See Drugs Approved for Breast Cancer for more information.
Ending the pregnancy does not seem to improve the mother’s chance of survival.
Because ending the pregnancy is not likely to improve the mother’s chance of survival, it is not usually a treatment option.
Treatment for breast cancer may cause side effects.
Treatment Options For Breast Cancer During Pregnancy
For information about the treatments listed below, see the Treatment Option Overview section.
Early Stage Breast Cancer
Pregnant women with early-stage breast cancer (stage I and stage II) are usually treated in the same way as patients who are not pregnant, with some changes to protect the unborn baby. Treatment may include the following:
- Modified radical mastectomy, if the breast cancer was diagnosed early in pregnancy.
- Breast-conserving surgery, if the breast cancer is diagnosed later in pregnancy. Radiation therapy may be given after the baby is born.
- Modified radical mastectomy or breast-conserving surgery during pregnancy. After the first 3 months of pregnancy, certain types of chemotherapy may be given before or after surgery.
Late-Stage Breast Cancer
Radiation therapy and chemotherapy should not be given during the first 3 months of pregnancy.
Special Issues About Breast Cancer During Pregnancy
- Lactation (breast milk production) and breast-feeding should be stopped if surgery or chemotherapy is planned.
- Breast cancer does not appear to harm the unborn baby.
- Pregnancy does not seem to affect the survival of women who have had breast cancer in the past.
Lactation (breast milk production) and breast-feeding should be stopped if surgery or chemotherapy is planned.
If surgery is planned, breast-feeding should be stopped to reduce blood flow in the breasts and make them smaller. Many chemotherapy 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 the mother's prognosis.
Breast cancer does not appear to harm the unborn baby.
Pregnancy does not seem to affect the survival of women who have had breast cancer in the past.
For women who have had breast cancer, pregnancy does not seem to affect their survival. However, 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 unborn baby does not seem to be affected if the mother has had breast cancer.
To Learn More About Breast Cancer During Pregnancy
For more information from the National Cancer Institute about breast cancer during pregnancy, see the following:
For general cancer information and other resources from the National Cancer Institute, see the following:
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