Fam-trastuzumab deruxtecan-nxki (T-DXd) showed statistically significant improvement in progression-free survival vs trastuzumab emtansine (T-DM1) in second-line treatment for HER2-positive unresectable or metastatic breast cancer, according to results from the global phase III DESTINY-Breast03 trial, which was presented by Javier Cortés, MD, PhD, and colleagues at a Presidential Symposium during the European Society for Medical Oncology (ESMO) Congress 2021.

In an analysis from the I-SPY2 trial reported in JAMA Oncology, W. Fraser Symmans, MD, and colleagues found that increasing residual cancer burden after neoadjuvant treatment for high-risk breast cancer was associated with poorer event-free survival.

Results from the phase III MONALEESA-2 trial showed a significant overall survival benefit with ribociclib plus endocrine therapy for postmenopausal patients with hormone receptor (HR)-positive, HER2-negative metastatic breast cancer. This is the first demonstration of a survival advantage with a front-line CDK4/6 inhibitor in postmenopausal patients with HR-positive/HER2-negative advanced breast cancer. Results were presented by Gabriel Hortobagyi, MD, and colleagues at the ESMO Congress 2021.

For patients with early-stage hormone receptor–positive breast cancer, extending the duration of letrozole after tamoxifen—for up to 8 years of total endocrine therapy—significantly improved invasive disease–free survival and overall survival over the standard treatment of approximately 5 years of endocrine therapy. Results from the Italian phase III GIM4 trial were presented by Lucia Del Mastro, MD, and colleagues at the European Society for Medical Oncology (ESMO) Congress 2021.

In a phase III trial (Pathways to Wellness) reported in the Journal of Clinical Oncology, Julienne E. Bower, PhD, and colleagues found that both mindfulness meditation and survivorship education interventions significantly reduced depressive symptoms in younger breast cancer survivors.