Drug Levels and Effects:

Summary of Use during Lactation:

High-dose breast radiation for the therapy of breast cancer can decrease or eliminate subsequent milk production in the treated breast, but not the untreated breast. Medical professionals sometimes advise mother's who have received breast cancer surgery and radiation not to breastfeed; however, it appears that these concerns are unfounded. Lower radiation doses to the breast in the treatment of Hodgkin lymphoma appear to have only a minor effect on subsequent lactation success. For information on diagnostic x-rays, see the LactMed entry for X-rays.

Effects in Breastfed Infants:

Relevant published information was not found as of the revision date.

Possible Effects on Lactation:

A woman who had been treated with high-dose external radiation and an iridium-192 implant for breast cancer became pregnant 1 year later and delivered a healthy infant. Her baby nursed equally well from both breasts. The treated breast produced milk that was slightly thicker with a quantity of about half the amount from the untreated breast.[1]

A review of medical records revealed 8 women who became pregnant after breast-conserving surgery, chemotherapy and radiotherapy for breast cancer. Of 8 women who attempted breastfeeding, 4 were successful. Breastmilk production was usually less or absent from the irradiated breast than from the contralateral breast.[2]

A survey of radiation oncologists identified 53 women who had been treated for breast cancer with surgical excision of the breast tumor and radiotherapy. In subsequent pregnancies, 18 of the women (34%) were able tolactate, although milk production was sometimes less in the affected breast. Thirteen (25%) were able to successfully breastfeed from the treated breast. The mean dose of radiation to the breast was 47 grays among those who lactated. The mean dose in women who could notlactatewas 50.6 grays. Most of the women received radiation from cobalt or a high-energy liner accelerator.[3]

In a retrospective study of 21 women with breast cancer treated with a median cumulative radiation dose of 50 grays to the affected breast, milk production in the irradiated breast was substantially reduced or eliminated in subsequent pregnancies. Milk production in the non-irradiated breast was usually not affected.[4]

A retrospective case-control study of 83 women who received radiation for Hodgkin lymphoma compared subsequent breastfeeding success to that of 70 sisters of patients who received radiation. The median dose of whole chest radiation was 41 grays (range 27 to 46 grays). There was a trend toward less success in breastfeeding in irradiated patients that was not statistically significant. The greater breastfeeding success relative to breast cancer patients in other studies was attributed to the lower radiation to the breast and less breast surgery in the Hodgkin lymphoma patients.[5]

Twenty women were identified from the European Institute of Oncology database who had breast cancer from 1988 to 2006 who agreed to take a survey of breastfeeding behavior. Fourteen of 15 women who underwent breast conserving surgery followed by irradiation reported hypoplasia of the irradiated breast during pregnancy. Of the 15 women, eight did not attempt to breastfeed. Of the 7 who attempted breastfeeding, one woman successfully breastfed 2 infants (2 pregnancies) for more than 6 months, one other successfully breastfed for 11 months. The duration of nursing in the other 5 women is unclear in the paper. Only two women attempted to breastfeed from both breasts, and both could breastfeed from both breasts for only 2 weeks because of reduced milk production. Of the women who did not attempt breastfeeding, medical counseling against breastfeeding was a major reason because of "uncertainty regarding maternal safety", and "

a priori

unfeasibility" expressed either by the obstetrician or the oncologist.[6]


1. David FC. Lactation following primary radiation therapy for carcinoma of the breast. Int J Radiat Oncol Biol Phys. 1985;11:1425. PMID:2989233
2. Higgins S, Haffty BG. Pregnancy and lactation after breast-conserving therapy for early stage breast cancer. Cancer. 1994;73:2175-80. PMID:8156522
3. Tralins AH. Lactation after conservative breast surgery combined with radiation therapy. Am J Clin Oncol. 1995;18:40-3. PMID:7847257
4. Moran MS, Colasanto JM, Haffty BG. Effects of breast-conserving therapy on lactation after pregnancy. Cancer J. 2005;11:399-403. PMID:16259870
5. McCullough L, Ng A, Najita J et al. Breastfeeding in survivors of Hodgkin lymphoma treated with chest radiotherapy. Cancer. 2010;116:4866-71. PMID:20629028
6. Azim HA, Bellettini G, Liptrott SJ et al. Breastfeeding in breast cancer survivors: pattern, behaviour and effect on breast cancer outcome. Breast. 2010;19:527-31. PMID:21078487

Substance Identification:

Substance Name:


Drug Class:

  • Radiation Therapy

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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