The hybrid SABCS 2021 could only attract a few hundred life attendees, but like every year, several key abstracts were presented. In early stage, a meta-analysis on aromatase inhibitor versus tamoxifen in premenopausal ER+ patients showed lower recurrence with aromatase inhibitors, while the impact on overall survival remains unclear. An EBCTCG meta-analysis showed no benefit for an anthracycline-taxane adjuvant chemotherapy regimen compared to a taxane only regimen, if the taxane was given sequentially after the anthracycline, confirming the role of anthracycline-free chemotherapy regimens in a large proportion of patients with early breast cancer. In ER+ metastatic disease, the new SERD elacestrant was more potent than classical endocrine therapy after progression on first/second line endocrine therapy. Datopotamab deruxtecan is a promising new ADC targeting TROP2 with clear activity in triple negative disease. In HER2 positive disease, T-DXd displayed substantial antitumour effect on brain metastases, and pyrotinib can be added to the list of highly potent HER2 tyrosine kinase inhibitors. In patients with HER2 mutations, neratinib showed clear antitumour activity both in ER positive and triple negative metastatic breast cancer. In the surgery field, black and Hispanic women were shown to be at higher risk for breast cancer related lymphedema after axillary lymph node dissection. The Italian SINODAR-ONE trial built further on the Z0011 trial and confirmed that axillary surgery can be omitted in patients with breast cancer patients and one or two macro metastatic sentinel nodes.

(BELG J MED ONCOL 2022;16(2):79–87)