Can Epithelial-Myoepithelial Carcinoma of the Breast Benefit from TROP2 Antibody-Drug Conjugate?

Epithelial-myoepithelial carcinoma (EMC) of the breast is a rare biphasic tumor composed of intermixed malignant epithelial and myoepithelial components. Breast epithelial myoepithelial carcinoma lacks therapeutic strategies due to its rarity, and currently local treatment is still the main treatment. Herein we report an epithelial-myoepithelial carcinoma of the breast in a 33-year-old woman undergoing breast conserving surgery, sentinel lymph node biopsy, adjuvant chemotherapy and radiotherapy, with rapid liver and lung metastasis. After radiofrequency ablation therapy for metastatic lesions, vinorelbine plus cisplatin and TROP2 antibody-drug conjugate (ADC) treatment were given successively. After a brief improvement, drug resistance developed and the disease progressed. The patient died with the PFS 5.6 months.