During the 2020 Virtual ESMO meeting, long-awaited results were presented of several important breast cancer studies. For hormone receptor positive (HR+) breast cancer, ESMO 2020 featured conflicting results on the use of CDK4/6 inhibitors in the adjuvant treatment of patients with hormone-receptor positive (HR+) early breast cancer. In HR+ metastatic breast cancer, final overall survival data were presented of the SOLAR-1 trial evaluating alpelisib in PIK3CA mutant patients. In triple negative breast cancer (TNBC), new data on immune therapy were presented. In early-stage TNBC, the addition of atezolizumab to neoadjuvant chemotherapy resulted in a significant increase in the rate of pathological complete responses (pCR). In the metastatic setting, final results of the IMpassion130 trial confirmed the benefit of atezolizumab combined with nab-paclitaxel as first-line treatment for metastatic PD-L1 positive TNBC. Unexpectedly, the IMpassion131 trial evaluating atezolizumab plus paclitaxel in first-line treatment of patients with metastatic TNBC failed to meet its primary endpoint. Finally, the phase III randomized controlled ASCENT trial identified the antibody-drug conjugate (ADC) sacituzumab govitecan as a safe and highly effective treatment option for heavily pre-treated metastatic TNBC patients.
