Diagnostic procedures and treatment (antimetabolites, hormone inhibitors, radioisotopes) for proliferative breast diseases are contraindicated while breastfeeding, at the moment of administration and for a variable period of time after completion. (Consult the file for each specific treatment). Keep in mind that the safe waiting period to breastfeed is, at least, 5 half-lives (T½) of the drug in question (Anderson 2016).After treatment for breast cancer, breastfeeding is possible. In breast cancer, when there is no residual tumor, breastfeeding can be achieved, either on the healthy or treated breast, whenever the patient has undergone conservative treatment. However, whether surgery or radiation is used, the latter instance may lead to less milk production, but always remaining the possibility of successful breastfeeding with one breast only. About 50% of women whose breast was irradiated may produce milk on that breast but only one in four women may breastfeed on it. Mechanical or manual removal of milk and/or formula supplementation may be required.Breast irradiation induces to less milk production, although nutritionally adequate, the infant may refuse it because of more sodium content than on the non-radiated breast. After radical and total mastectomy, there is not possibility to breastfeed in the future because of lacking to conservation of breast tissue, nipple or both. Only after partial subcutaneous mastectomy with preservation of part of breast tissue, breastfeeding may be feasible. Breastfeeding after breast cancer poses no danger to the mother nor the child, either if it is from the healthy breast or not. The mother will require appropriate information and assistance along with professional and family support. Breastfeeding is often more difficult when it must be done on one breast only, with a lot of emotional and physical stress together with frustration if exclusive breastfeeding is not achieved. Prestigious Medical and Oncology Societies offer support to mothers who want to breastfeed after such an ordeal. See below the information of this related group: