Breast Cancer and Pregnancy


You may experience many unpleasant things during pregnancy, but breast cancer should not be one of them. Unfortunately, breast cancer does sometimes occur in women who are pregnant or who have just given birth. According to the National Cancer Institute, breast cancer is diagnosed in about one in every 3,000 pregnant women, most of whom are between the ages of 32 and 38.

Detecting breast cancer can be difficult even under normal circumstances, but it can be even more difficult to diagnose breast cancer during pregnancy, when changes in a woman’s breasts can make small lumps even more difficult to detect, which may lead to delays in diagnosis. As a result, cancers may reach a later stage in pregnant women before they are discovered.

Treatment and prevention of breast cancer during pregnancy is similar to treatment and prevention of breast cancer under normal circumstances. The best thing you can do to protect yourself from breast cancer is to know its signs and symptoms, examine your breasts frequently for lumps, and contact your doctor immediately if you find a lump or have any concerns.

Distinguishing Between Breast Cancer and Pregnancy Symptoms

One of the early signs of pregnancy is breast tenderness. This can be quite painful at times, and may continue throughout your pregnancy. A pregnant woman’s breasts begin to swell in the first trimester and can grow to three cup sizes larger than they were before pregnancy. Swollen, tender breasts can make detection by self-examination more difficult. Other breast changes during pregnancy include darkening of the areolas and enlargement of the tiny bumps on the areola. While all these changes can be alarming, they should not be confused with the symptoms of breast cancer.

A common sign of breast cancer is a hard lump in the breast that won’t go away. The lump may be confused with a calcification, which is common among women who are breastfeeding. The following signs and symptoms may be caused by cancer, but the National Cancer Institute warns that conditions other than breast cancer may cause these same symptoms:

•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.


Diagnosing Breast Cancer During Pregnancy

If you have a palpable mass in your breast that persists for more than two weeks, you should contact your doctor immediately for an evaluation.

After taking your medical history and conducting a complete physical examination, your doctor will carefully feel for any lumps or abnormalities in and around your breasts and underarms. He or she may also order one or more of the following tests:

•Mammogram: This radiograph of the breast can be performed with little risk to the fetus. Reported sensitivity of mammography for detecting breast cancers in pregnancy ranges from 63 to 78 percent (Womens Health [London England], 2009).

  • Ultrasound examination: Ultrasound is used to distinguish between cystic and solid breast masses and does not carry with it any risk for fetal radiation exposure. Ultrasound has been found to be more accurate than mammography in detecting masses.

•Magnetic resonance imaging (MRI) of the breasts: The use of this test is not widely accepted because of the possible risk to the fetus. It may be used as an adjunct to ultrasonography or as part of staging.

•Biopsy: If a lump in the breast is found, your doctor may need to remove a small piece of it for microscopic examination by a pathologist. There are four types of biopsies: excisional biopsy, incisional biopsy, core biopsy, and fine-needle aspiration biopsy.

•Blood chemistry studies: Blood tests may be ordered to detect cancer in other parts of the body or to rule out an underlying health problem or illness.

Further testing involving a chest x-ray with proper shielding, ultrasound of the liver, and a noncontrast MRI of the thoracic and lumbar spine to rule out bone metastases may be required for staging of the cancer.

Treatment of Breast Cancer During Pregnancy

Although treatment options for pregnant women are basically the same as for non-pregnant women, extra precautions are taken for pregnant women to prevent harm to the fetus.

Surgery and procedures: Breast surgery can be safely performed in all trimesters. Often surgery is postponed until after week 12 of gestation, when the risk of spontaneous abortion decreases. Depending on when the cancer is detected, patients may need to have a mastectomy, or they may be able to opt for preoperative chemotherapy during pregnancy with an option for lumpectomy and radiation after delivery. Sentinel lymph node biopsy is not routinely performed during pregnancy, and the use of isosulfan blue-dye mapping is not recommended.

Breast cancer medications and radiation: Chemotherapy can be considered after the first trimester. Biologic agents and endocrine therapy are generally avoided during pregnancy, but if they are necessary they should be initiated after delivery. Radiation therapy should also be postponed until after delivery. Breastfeeding during administration of chemotherapy, biologic therapy, endocrine therapy, or radiation therapy is not recommended.

Breast Cancer Occurrence in Future Pregnancies

This is a major concern for pregnant women with breast cancer. However, women who have a subsequent pregnancy after a diagnosis of breast cancer do not appear to have an increased risk of recurrence.

Prevention of Breast Cancer in Pregnancy

Making the following lifestyle changes can decrease your risk of breast cancer:

•Limit alcohol

•Don’t smoke

•Control your weight

•Be physically active


•Limit dose and duration of hormone therapy

•Avoid exposure to radiation and environmental pollution

•Eat a healthy diet

While eating a diet rich in fruits and vegetables hasn’t been consistently shown to offer protection from breast cancer, new studies suggest that intake of certain vegetables may have a greater impact on reducing your cancer risk than was once thought. Past animal and in vitro studies have shown that intake of cruciferous vegetables can inhibit cancer growth and progression. Cruciferous vegetables, especially Brussels sprouts and broccoli, are a major source of glucosinolate-derived bioactive compounds such as isothiocyanates. The protecting effects against cancer risk have been attributed, at least partly, due to their comparatively high amounts of glucosinolates, which differentiate them from other vegetables (Asian Pacific Journal for Cancer Prevention, 2013). Although one recent study could not find an association between postdiagnosis cruciferous vegetable intake and breast cancer outcomes (Cancer Epidemiology Biomarkers & Prevention, 2013), another recent study found the inhibition of breast cancer stem cells at pharmacologic concentrations of benyl isothiocyanate (Cancer Prevention Research [Philadelphia], 2013). Although the findings are encouraging for women with breast cancer, more research is needed to determine a clear benefit. In the meantime, it could not hurt to try to incorporate foods with anti-carcinogenic properties into your daily diet.

This page was last updated on 06/2017

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