Trastuzumab Deruxtecan for Human Epidermal Growth Factor Receptor 2-Low Breast Cancer With Cancer-Related Microangiopathic Hemolytic Anemia: A Case Report

Abstract

The diagnosis of cancer-related microangiopathic hemolytic anemia (CR-MAHA) in patients with breast cancer is often delayed, and this condition is associated with high mortality. A 71-year-old female with CR-MAHA secondary to bone marrow metastasis received trastuzumab deruxtecan (T-DXd) after first-line chemotherapy failure and achieved partial hematological remission. Treatment was discontinued because of interstitial lung disease (ILD). Early antitumor therapy is crucial; antibody-drug conjugates such as T-DXd offer promise, but vigilance for adverse effects is needed.