Breast cancer survivors given new hope for breastfeeding, studies show

Two groundbreaking international studies have revealed that breastfeeding after breast cancer may be safer than previously thought, potentially transforming advice given to survivors who wish to have children.

The findings, presented at the 2024 Annual Meeting of the European Society for Medical Oncology (ESMO), challenge long-held concerns about hormonal changes during breastfeeding potentially increasing cancer recurrence risks.

Dr Fedro Alessandro Peccatori, director of the Infertility Unit at the European Institute of Oncology in Milan and lead researcher of the POSITIVE study, said: “Before these data, doctors were very cautious, perhaps even defensive, about the possibility and safety of breastfeeding after breast cancer.”

The POSITIVE study, involving 518 women from 20 countries with hormone receptor-positive breast cancer, found no significant difference in 24-month recurrence rates between those who breastfed and those who did not.

A second study, led by Dr Eva Blondeaux from Ospedale Policlinico San Martino in Genoa, focused on 4,732 young women with BRCA gene mutations. It similarly found no significant differences in local recurrences or contralateral breast cancer development between breastfeeding and non-breastfeeding groups over a seven-year follow-up period.

“These are the first indisputable encouraging results regarding the safety of breastfeeding after breast cancer in young women with BRCA mutations,” Dr Blondeaux stated, whilst calling for further prospective studies to confirm the findings.

The research comes as improving survival rates have allowed more breast cancer survivors to consider motherhood. Recent years have seen studies demonstrating the possibility of safe pregnancies after breast cancer, even with assisted reproduction.

Experts from the University of Athens, including Dr Maria Kaparelou, Professor Theodora Psaltopoulou, and Professor Thanos Dimopoulos, emphasised that these results provide a basis for more nuanced counselling, considering both the mother’s oncological safety and the needs of mother and child.

While the studies offer promising evidence, researchers stress that individual medical advice will still depend on factors such as cancer type, treatment history, and breast condition.