Finding breast cancer during pregnancy
Breast cancer can be difficult to detect during pregnancy. Normal breast changes that occur during pregnancy, such as larger, more tender, and lumpy-feeling breasts, can make it difficult to find small masses during clinical breast exams and self-exams.
Increased breast density during pregnancy can also make it harder to find breast cancer with a mammogram. Breast density is higher during pregnancy because hormonal shifts increase glandular tissue and reduce fat in preparation for lactation. Additionally, women who are pregnant or nursing are often below the age at which mammogram screening is recommended.
Because these factors can delay a breast cancer diagnosis and because younger women are more likely to have aggressive forms of the disease, breast cancer is often found at a later stage in women who are pregnant or nursing.
If you are pregnant or nursing, you should receive clinical breast exams during regular prenatal and postnatal check-ups. However, most women diagnosed with pregnancy-associated breast cancer find a lump on their own. If you are pregnant or nursing, be aware of changes in your breasts. Talk to your doctor right away if you notice any changes that worry you.
Diagnosing breast cancer during pregnancy
The same tests used to diagnose breast cancer in women who are not pregnant can be used in women who are pregnant. The first test to evaluate a suspicious mass is typically an ultrasound, which does not involve radiation. Mammograms involve only a small amount of radiation and can safely be used to further evaluate a mass. Biopsies are also safe to have during pregnancy.
If you are diagnosed with breast cancer, additional tests may be needed to determine the stage of the disease. Some tests, such as CT or PET-CT scans that are used to stage breast cancer in women who aren't pregnant, may be dangerous for a developing fetus or a nursing baby due to radiation or use of dyes or radioactive tracers. These tests are done only if absolutely necessary. Certain precautions, such as covering the abdomen with a lead shield, are taken to ensure that the fetus is exposed to the lowest possible amount of radiation.
Different tests and procedures may be used to stage breast cancer in women who are pregnant or nursing than in women who are not. Tests that may safely be used to stage breast cancer during pregnancy include ultrasound and MRI with limited use of contrast.
To learn more about the tests and procedures used to diagnose and stage breast cancer, visit How Breast Cancer Is Diagnosed.
Prognosis for women with breast cancer during pregnancy
The prognoses for pregnant and nonpregnant women with breast cancer may differ. Research results have been mixed. Some studies show prognosis is similar if cancers are found at the same stage; however, other research shows worse outcomes for those diagnosed when pregnant.
Ending a pregnancy or stopping lactation does not necessarily improve a woman's chance of survival, although this depends on the type of cancer and stage at diagnosis.
For women who have had breast cancer in the past, getting pregnant does not seem to increase the risk that the cancer will come back. However, some doctors recommend waiting 2 years after treatment for breast cancer before getting pregnant so that an early return of the cancer would be more easily detected. For women on adjuvant hormone therapy, subsequent pregnancy attempts require stopping it and then waiting a few months before trying to become pregnant. Hormone therapy can then be started again after the baby is born. To learn more about pregnancy after cancer, visit Female Fertility and Cancer Treatment.
Treating breast cancer during pregnancy
Treatment options for pregnant women depend on the stage of the disease and the trimester of the pregnancy.
Pregnant women with early-stage breast cancer (stage I and stage II) are usually treated in the same way as women who are not pregnant, with some changes in the timing of certain treatments to protect the fetus. Treatment may be more complicated in pregnant women with late-stage breast cancer (stage III and stage IV) because some treatments may need to begin quickly and could harm the fetus. Ending a pregnancy may be considered if the cancer is fast-growing or advanced and treatment is needed right away. The ability to safely terminate a pregnancy because of an advanced cancer diagnosis may vary based on your state of residence.
Treatment for breast cancer during pregnancy may include:
- Surgery. Most pregnant women with breast cancer have a lumpectomy, also called breast-conserving surgery, or a modified radical mastectomy to remove the breast. Some of the lymph nodes under the arm may be removed so a pathologist can check them under a microscope for signs of cancer. If surgery is planned and the woman has already given birth, breastfeeding should be stopped to reduce blood flow in the breasts and make them smaller. Learn more about Breast Cancer Surgery, including reconstruction.
- Chemotherapy. After the first 3 months of pregnancy, certain types of chemotherapy may be given before or after surgery. Chemotherapy given at this time does not usually harm the fetus but may cause early labor or low birth weight. Chemotherapy also should be avoided 3 to 4 weeks before delivery, because it can cause delivery complications for both the mother and baby. Women receiving chemotherapy should not breastfeed. Many chemotherapy drugs may be found in high levels in breast milk and could harm the nursing baby. Learn more about Chemotherapy for Breast Cancer.
- Radiation therapy. Delaying radiation therapy until after the baby is born is usually the safest option. Women with late-stage breast cancer (stage III or stage IV) may consider external radiation therapy after a careful assessment of the risks and benefits. Talk with your doctor about the risks and benefits of radiation therapy as you discuss your treatment plan. Learn more about Radiation for Breast Cancer.
- Other treatments. Hormone therapy, targeted therapy, and immunotherapy are usually not given to pregnant or nursing women because these treatments are harmful to a fetus or a nursing baby.
Clinical trials
Joining a clinical trial specifically designed to include women who are pregnant or nursing may be an option. Examples of these types of trials may include a treatment trial that tests new treatments or new ways of using existing treatments in pregnant women or a registry trial that tracks outcomes.
However, despite the need for research, pregnant and lactating women are often excluded from breast cancer clinical trials because of the complexity of managing treatment and concerns about potential harm to the fetus.
You can use the clinical trial search to find NCI-supported cancer clinical trials that are accepting participants. This search allows you to filter trials based on the type of cancer, your age, and where the trials are being done. You can also review a list of all current Breast Cancer Clinical Trials.
Learn more about clinical trials at Cancer Clinical Trial Information for Patients and Caregivers.
Coping with breast cancer during pregnancy
Breast cancer during pregnancy is especially challenging, both mentally and physically. It is important that you bring up any questions and concerns you have with your health care team throughout your care and treatment to get the support you need.
In addition to support from your health care team and family, one-on-one counseling or in-person and online support groups can help you cope and improve your mental wellbeing. To learn more about how to manage the physical and emotional effects of breast cancer, visit Living with Breast Cancer and Survivorship.