Breastfeeding following lumpectomy and radiation therapy for breast cancer

I am a physical therapist, childbirth educator and lactation counselor from Israel, temporarily residing in the States. I have a question about breastfeeding after radiation therapy for breast cancer.  The woman is 42 years old. She has a 7 year old son whom she breastfed for 2 years. Her milk supply was high during that lactation. She is now 17 weeks pregnant. A year ago she had breast cancer in her left breast and had a lumpectomy, radiation and some lymph nodes removed.  The “affected” breast has not grown as the other one has during pregnancy.

Could you share any information or experience with clients with the same condition and their experience with breastfeeding after radiation? I want to support her as much as I can.

Amy Shapira – Georgia

Pregnancy following breast cancer is becoming more common, and because of breast conserving therapies, women now seek information about how a previously treated breast will respond during lactation.  Some of the published articles we reviewed for the chapter on breast cancer in the 4th edition of The Breastfeeding Atlas report that the breast is no longer capable of lactation following radiation therapy.  A few case studies, however, have described milk production in the treated breast following delivery of an infant.  In these cases, the appearance of the milk has been altered, looking thicker and somewhat discolored. Perhaps the discolored milk may result from debris in the ducts (dead cells). The reported cases uniformly describe diminished milk production.

BWC has worked with 4 women whose previously irradiated breasts became engorged following delivery.  Two opted to wean that breast immediately.  Two decided to breastfeed from the affected breast even though the milk looked different.  The infants of these 2 women preferred breastfeeding from the untreated breast, but appeared to suffer no ill effects from nursing on the affected one.  In both cases, milk flow was slow and the volume of milk was very low on the treated breast.  Pumping usually produced only drops or, at best, enough milk to cover the bottom of a bottle.  The low volume probably caused the breast preference, but perhaps the taste of the milk was altered. We know that weaning milk (milk in low volume) has increased sodium and chloride levels, and tastes salty.   Both the mothers in BWC’s practice who breastfed following radiation therapy tended to use the treated breast more for pacification and soothing, and depended on the healthy breast for feeding.

Any type of invasive breast surgery (including lumpectomy) damages the internal structure of the breast and interrupts normal drainage of milk.  Scar tissue may also create blockages. Even if radiation has not totally destroyed the lactational capacity of the breast, surgically affected breasts tend to not drain normally.  Care providers must be watchful for mastitis. The presence of any lumps in the breast is very upsetting to the mom who has had breast cancer, so she will need anticipatory guidance and education about signs and symptoms of mastitis.

This mother should, of course, be carefully monitored. The most risky time for pregnancy in women who have had breast cancer is within 2-3 years of the diagnosis.  This mother falls within that time frame, so it is prudent to be watchful and to err on the side of caution.  She will need lots of emotional support as well.  Generally, women who have had breast cancer get periodic blood work to check for tumor markers.  It will be important not to become “distracted” by the fact she is lactating or to ignore changes in skin texture or color or lumps that should be visualized to rule out recurrence of cancer.

While pregnancy itself may be somewhat of a risk factor (depending on timing), there is no evidence that it is harmful to breastfeed following treatment for breast cancer.  While it is unlikely the treated breast will produce a full supply of milk, one breast is generally capable of nourishing one baby.  Remind her that twins can thrive while feeding from only one breast. In our experience, that is typically very reassuring information for women who have only one healthy breast.  Because she will worry about whether the baby is getting enough, provide education about normal weight gain and what to expect with regard to feeding frequency.  Such information will help her distinguish between normal infant feeding behavior and signs which might reflect real problems with intake.

We have made Chapter 12 from The Breastfeeding Atlas, 5th edition, available here as a pdf file which individuals may download for personal information and study. This chapter reviews breast cancer. In addition, we would like to refer people seeking more information about breast cancer in women of reproductive age to Lawrence and Lawrence, Breastfeeding: A guide for the medical profession, which contains a brief, but excellent review of this subject.

View PDF


Burns P.  Absence of lactation in a previously radiated breast.  Int J Radiation Oncology, Biology, Physics 1987, 13:1603.

Camune B, Gabzdyl E.  Breastfeeding after breast cancer in childbearing women. J Perinatal and Neonatal Nurs 2007; 21(3):225-233.

David F. Lactation following primary radiation therapy for carcinoma of the breast.  Int J Radiation Oncology, Biology, Physics 1985; 11(7):1425.

Higgins S, Huffy B.  Pregnancy and lactation after breast-conserving therapy for early stage breast cancer. Cancer 1994:73(8):2175-2180.


  1. Dandy says

    Thank you so much for this information. I am a 30 year old bc survivor and an now pregnant with my first child. There is very little information on breastfeeding after lumpectomy and radiation. I really appreciate this post!

  2. Tracie says

    Thank you for posting this information. I am 5 months pregnant with my first baby, after undergoing a lumpectomy, chemotherapy, and heavy radiation to my right breast three years ago. There is a marked difference in my breast’s sizes as the pregnancy progresses. The affected side is not growing, as the other other is, well, thriving. It is hard to know what to expect, and with the possibilities of mastitis and blocked ducts, having only one breast to work with can be a scary thing.
    I look forward to hearing more experiences in this instance, and sharing my own when the baby is born.

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