Being overweight or obese can reduce the benefit of extending adjuvant breast cancer hormone therapy in women younger than 60 years, according to research from the DATA trial discussed at the European Society for Medical Oncology (ESMO) Breast Cancer 2023 Congress.

Senna W.M. Lammers, MD, from Maastricht University Medical Centre in The Netherlands, reported her findings from the DATA trial looking at the benefit of extending adjuvant hormonal therapy by treating women with hormone receptor-positive breast cancer who had already received tamoxifen with an additional course of anastrozole.

The study confirmed an overall benefit in disease-free survival from extending the endocrine therapy, but also found this was impacted by body mass index: with overweight and obese patients benefiting less if they were under the age of 60.