Women are being diagnosed younger and younger, raising concerns about pregnancy and breast cancer.

How common is breast cancer in pregnancy?

Breast cancer during pregnancy is very rare. It occurs in about one out of every 3000 pregnant women. It is the most common cancer in pregnant women and usually occurs in women in their thirties or older.

How is breast cancer detected in pregnancy?

Breast cancer in pregnancy is most often diagnosed when either the woman or her doctor find a lump. As it can be difficult for pregnant women to detect lumps (the breasts become larger and tender), it is important that doctors perform routine breast examinations during pregnancy.

The earlier a lump is found the easier it is to treat. As a general rule any lump that was not there before, or that does not disappear within two weeks, should be investigated.

A mammogram may not be helpful because of increased breast density in pregnancy but can be performed safely with the proper shielding of the growing foetus. A breast ultrasound can be performed safely, followed by a breast biopsy to finalise the diagnosis.

How is breast cancer treated in pregnancy?

The type and timing of treatment depends on many things, such as:

• Size of tumour

• Location of tumour

• Whether, and how far, the cancer has spread

• How far along the pregnancy is

• What the women prefers.

Treatment goals in pregnancy are the same as in non-pregnant women: to control the cancer in the place where it started and to prevent spread. The additional challenge of protecting a growing baby makes everything more complicated. Radiation therapy is not used in pregnancy as it causes miscarriages, birth defects and impaired foetal growth. Hormone therapy such as Tamoxifen, is not recommend for use in pregnancy. Treatment options are surgery (mastectomy or local excision of the tumour) and chemotherapy (not usually given in the first 12 weeks of pregnancy). One option would be an early, planned delivery of the baby if the pregnancy is advanced, and the baby’s chances of survival are good.

Research has not shown that termination of pregnancy improves breast cancer outcomes and this is not usually considered as a therapeutic option. However, if the cancer is aggressive, was diagnosed late or high dose chemo and radiation is needed, termination might have to be discussed in order to allow for proper treatment.

Can I get pregnant after successful treatment for breast cancer?

Some treatment for breast cancer, mainly chemotherapy drugs, may affect a woman’s fertility – damaging the ovaries and causing the early onset of menopause, especially in older women. In younger women this may be less permanent and fertility can return a few months or years later.

There is a clear link between oestrogen levels and the growth of breast cancer cells, making it advisable for breast cancer survivors to wait at least two years after treatment before trying to get pregnant. This is thought to provide time to detect an early return of the cancer.

Most studies indicate that pregnancy does not increase the risk of cancer recurrence after successful treatment. The desire to fall pregnant should be weighed up against a number of factors such as age, type of breast cancer and risk of early relapse. Your team of caregivers, (obstetrician, surgeon, oncologist and psychologist) can provide invaluable advice.

Can I breastfeed my baby if I have breast cancer?

Chemotherapy, when completed prior to delivery, has been shown to significantly decrease milk production. So breastfeeding in this instance may be difficult.

Breastfeeding whilst having breast cancer will not harm the baby. Moreover, there is no evidence that stopping the flow or production of breast milk will improve the cancer or survival.

However if a woman is undergoing chemotherapy for breast cancer, breastfeeding is not recommended as these powerful, potentially harmful drugs are transferred to the baby via the breast milk. Depressed immunity, bone marrow suppression and low white cells counts have been reported in infants who have been nursed by mothers on chemotherapy.


Dr Sumayya Ebrahim is a gynaecologist in private practice in Johannesburg. She is also a blogger. Check out her blog “vaginations by Dr E” on

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