Metastatic Lobular Breast Cancer: Outcomes of Patients Treated at a Single Tertiary Institution

This study aligns with existing literature in terms of the clinical characteristics of early lobular breast cancers. For metastatic disease, HR+HER2- lobular breast cancer treated with CDK4/6 inhibitors and non-steroidal aromatase inhibitors had a similar progression-free survival compared to the registration trial data supporting its use for lobular cancer. There were also some responses to chemotherapy, with all patients who received capecitabine obtaining clinical benefit. Patients with HER2+ disease had excellent outcomes, while outcomes were poor for triple-negative lobular breast cancer, though the small number of patients in our study limits interpretation.