Breastfeeding after breast cancer is safe

Dr Eva Blondeaux - Ospedale San Martino, Genova, Italy

We previously demonstrated that pregnancy after breast cancer is safe for the mother, with no increased risk of recurrences even among BRCA carriers, but to date there are very few data regarding breastfeeding after breast cancer, also in BRCA carriers. We aim to provide the first evidence on this topic, on the feasibility and safety of breastfeeding, because we know that from the ipsilateral breast the surgery and radiotherapy can impact the women’s ability to breastfeed. Thus, there were concerns among oncologists on how to counsel these patients regarding safety and feasibility, because no data were available on maternal safety and on recurrences in these patients.

Our aim was to evaluate feasibility and safety. We included almost 5,000 young BRCA carriers with a history of breast cancer at a young age, and among those more than 600 had a pregnancy after breast cancer, of whom 474 had a live birth, so were able to decide whether to breastfeed or not. Among those 474 patients, almost half had a risk-reducing mastectomy before delivery, so were not even able to breastfeed. Among these women, around one out of five opted for breastfeeding. We firstly demonstrated that breastfeeding is safe, with no increased risk of recurrences in these women, and we also observed that women that decided to breastfeed were more frequently nulliparous at the time of breast cancer diagnosis, and did not report prior smoking habit. So maybe lifestyle factors can influence the women’s decision to breastfeed.

What is the impact of this study?

Our findings will hopefully improve the way we counsel these patients, because until today no data were available; this is the first evidence specifically focusing on BRCA carriers. So we really hope that our results will improve the knowledge and help clinicians to counsel these patients, because in BRCA carriers there is a consistent risk of relapse and risk of a second primary breast cancer in this population. Thus, patients are frequently counselled regarding the possibility of undergoing risk-reducing mastectomy. But still, if the patient is willing to breastfeed, we firstly demonstrate that is safe, so we can reassure these patients that they will not have increased risk of second primary breast cancers and local regional recurrences.