Breast cancer surgery

Does cancer surgery affect milk supply?

Breast cancer surgery is usually aggressive and will significantly decrease the milk supply in the affected breast. Even if part of the breast remains, milk tissue is often badly damaged. Breast cancer may also be treated with irradiation or chemotherapy, which can damage milk tissue. Breastfeeding mothers who have had breast cancer surgery or other breast cancer treatment need to ensure that their babies are taking in enough milk. Some mothers will have enough milk as the unaffected breast can compensate by making extra milk but others may not. Breastfeeding after breast cancer does not appear to increase the risk of breast cancer returning.

A) Breast cancer surgery

Surgery for breast cancer is generally very aggressive and may significantly decrease the milk supply in the affected breast.

In a total mastectomy all of the breast is removed.

In a partial mastectomy, the cancer and a good amount of healthy tissue surrounding it is removed. The breast may be further damaged by radiation treatment. It is very unlikely that such a breast will be able to make significant amounts of milk (Moran 2005).

Chemotherapy can reduce the amount of milk that the remaining breast can make (Johnson 2019).

Some mothers may have enough milk in the healthy breast to compensate for a low milk supply in the affected one but other mothers may not (Michaels 2013). Mothers who have had breast cancer treatment need to ensure that their babies are getting enough milk and if not, supplement them with milk

There is no information about the safety of herbs or medication to increase the amount of milk when used by breast cancer survivors (Bhurosy 2020; Johnson 2020).

Other breastfeeding problems are also possible.  

Breastfeeding after breast cancer does not appear to increase the risk of breast cancer returning (Johnson 2019).

References

Bhurosy T, Niu Z, Heckman CJ. Breastfeeding is Possible: A Systematic Review on the Feasibility and Challenges of Breastfeeding Among Breast Cancer Survivors of Reproductive Age. Ann Surg Oncol. 2021 Jul;28(7):3723-3735

Johnson HM, Mitchell KB. Breastfeeding and Breast Cancer: Managing Lactation in Survivors and Women with a New Diagnosis. Ann Surg Oncol. 2019 Oct;26(10):3032-3039

Johnson HM, Mitchell KB, the Academy of Breastfeeding Medicine. ABM Clinical Protocol #34: Breast Cancer and Breastfeeding. Breastfeeding Medicine 2020;15(7)

Moran MS, Colasanto JM, Haffty BG, et al. Effects of breast-conserving therapy on lactation after pregnancy. Cancer J. 2005 Sep-Oct;11(5):399-403
 
Michaels AM, Wanner H. Breastfeeding twins after mastectomy. J Hum Lact. 2013 Feb;29(1):20-2