CCoPE
Date: 2002-09-20

Question:
This question is regarding a woman who is currently pregnant (EDD: 31 October) and undergoing chemotherapy for a breast tumor that was detected in her fourth month of pregnancy. She has undergone chemotherapy 3 times (q 3 weeks) and anticipates one or two more rounds prior to delivery, after which further treatment (ie. radiation and surgery) will be discussed. She has been receiving a combination of 5FU, Adriamycin and Cyclophosphamide. The questions have to do with the possibility of her breastfeeding: Is it possible to breastfeeding while receiving these drugs? If the drugs are contraindicated to breastfeeding, how long after a chemo treatment could she breastfeed? (eg. if her last chemo was a month prior to delivery would it be safe to breastfeed following delivery?) If she receives radiation is it possible to breastfeed on the unaffected breast? Similarly, would she be able to breastfeed from the unaffected breast following surgery? Any information you may have would be welcomed as soon as possible. Thank you.

Answer:
Radiation is not a concern in the context of breastfeeding: there is no radioactive substance produced and excreted in milk. Cyclophosphamide and doxorubicin (in the same groups as adriamycin) are listed as drugs of concern. There are very few reports of infants breastfed by women on these drugs, but in one case, cyclophosphamide was believed to be the cause of low white blood cell count of the baby. But, overall, infant exposure to these drugs is at much higher level in pregnancy than in breastfeeding. If she can pump and wait until the chemo cycle is over, that would be the best. If the interval bewteen the chemo and feeding is more than a week, there may be little concern.