At this year’s annual meeting of the European Society of Medical Oncology (ESMO) experts shared some game-changing data for the treatment of breast cancer (BC). In advanced HER2+ metastatic breast cancer m(BC), the DESTINY-Breast03 trial performed a head-to-head comparison of T-DM1 and trastuzumab deruxtecan (T-Dxd) following initial treatment with trastuzumab and a taxane, showing a major PFS benefit for T-DXd without major toxicity issues, establishing T-DXd as the new standard of care in this setting. In luminal breast cancer, the final analysis of the GIM-4 study supports the use of 7 years instead of 5 years adjuvant endocrine therapy in postmenopausal patients with hormone receptor positive (HR+)/HER2- early BC. For advanced stage HR+/HER2- BC, the MONALEESA-2 study shows >1y OS benefit when adding the CDK4/6 inhibitor ribociclib to letrozole as first-line treatment. Finally, in triple negative breast cancer (TNBC), the phase III BrighTNess study showed that addition of carboplatin to neoadjuvant chemotherapy provides long term EFS benefit. In metastatic TNBC, OS data of KEYNOTE-355 further support the use of first-line pembrolizumab plus chemotherapy in advanced PD-L1+ TNBC.

(BELG J MED ONCOL 2021;15(8):390–7)