Breast cancer, a malignant disease that affects about 1 in every 8 women, is known to be caused by an acquired or inherited DNA mutation. While reasons for the defect are not fully understood, studies have identified risk factors impacting the development of the disease. One of these factors is age, which is why the cancer mainly occurs in older women. But younger women are hardly immune.

Breast cancer during pregnancy is particularly rare, but also the most common form of cancer in women who are pregnant, breastfeeding, or within a year of giving birth. It occurs in about 1 in every 3,000 expectant mothers, according to estimations from the American Cancer Society. Breast cancer during pregnancy is often referred to as gestational breast cancer or pregnancy-associated breast cancer (PABC). The society believes that, due the increasing numbers of women having children later in life, the rates of breast cancer during pregnancy will also increase. This type of cancer has special concerns that need to be taken into consideration.

Diagnosis of Breast Cancer During Pregnancy

“When a pregnant woman develops breast cancer, it’s often diagnosed at a later stage than it would be if the woman were not pregnant. It’s also more likely to have spread to the lymph nodes. This is partly because hormone changes during pregnancy,” the American Cancer Society (ACS) says. “Pregnancy stops monthly menstrual cycles and the levels of estrogen and progesterone go up. Prolactin, a hormone that tells the breasts to prepare for nursing, also goes up during pregnancy. These hormone changes cause the breasts to change. They may become larger, lumpy, and tender. This can make it harder for the woman or her doctor to notice a lump caused by cancer until it gets quite large.”

Diagnosis of breast cancer in pregnant women is more difficult than in other women. Two of the main challenges are delays in breast cancer screening, often postponed until after the baby is born because of fears of radiation exposure to the fetus, and, as mentioned, increases in breast tissue density during pregnancy and breastfeeding, making a tumor more difficult to identify.

If any alterations in breast tissue are noticed and of concern, the physician will need to perform specific tests. If a mammogram is unwanted or not recommended during pregnancy, alternatives like imaging tests (MRI or ultrasound) are possible. The physician may request a biopsy to collect a sample of tissue and analyze it. During pregnancy, the biopsy is usually done with a needle; only if the results are inconclusive is a surgical biopsy likely to be performed. The disease stage will also need to be analyzed, and in pregnancy this is usually done through tests like ultrasound, magnetic resonance imaging (MRI) scans, or chest X-rays. Women may be concerned about the baby’s safety, but X-rays involve small amounts of radiation and the mother’s belly should be shielded. PET scans, bone scans, or computed tomography (CT) scans involve more radiation, and are less likely to be given unless absolutely necessary.

Treatment of Breast Cancer During Pregnancy

Both the prognosis and treatment of breast cancer during pregnancy vary depending on factors like cancer stage and location, type of cancer, age of the unborn baby, signs or symptoms, or a woman’s general health. The disease is unlikely to affect the baby, but the best treatment option for the mother may be harmful for the child, which is why pregnant women are not treated like other breast cancer patients.

Surgery is thought to be safe for both mother and child, and it is done for a single purpose in all women — to control the disease and prevent it from spreading. “As with women who are not pregnant, surgery is usually the first step for treating early-stage breast cancer. Surgery during pregnancy can be safely performed with little risk to your unborn child, so your medical team will most likely proceed by removing the lump with a lumpectomy or mastectomy, and possibly some lymph nodes from under the arm,” the National Breast Cancer Foundation reports.

Treatments like chemotherapy, hormone therapy, targeted therapy, and radiation therapy, however, may be delayed until after the birth due to the possibility of risk to the fetus (especially hormone and targeted therapy). Only chemotherapy is thought able to be administered without harm, if the pregnancy is in its later stages (at least second trimester). But women with inflammatory breast cancer or other aggressive cancer forms may be advised not to wait for a range of treatments, as delay can be very dangerous. These women, like all breast cancer patients, need to carefully consider their options, and discuss them fully with their physician.

Breastfeeding is not advised for women who have recently given birth and are about to undergo cancer treatment, including surgery.

Note: Breast Cancer News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.