ERBB2 and extramammary Paget disease: Further, several case reports have shown the HER2-targeted antibody trastuzumab alone or with cytotoxic chemotherapies to be effective against metastatic or advanced EMPD in ERBB2-mutant or HER2/ERBB2-overexpressed cases (Supplemental Table S1) [14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30].