If a patient with HER2+ uterine serous carcinoma recurs while on maintenance trastuzumab, would you continue trastuzumab with second line chemotherapy?

I advise against extrapolating data from breast cancer therapies to endometrial cancer. There is no clinical trial supporting the administration of trastuzumab (or other anti-HER2 therapy) with second line chemotherapy after progression on maintenance trastuzumab in serous endometrial cancer. Rather...

Extrapolating from HER2+ (ERBB2-amplified) breast cancer, treatment is a HER2-targeted agent plus cytotoxic chemotherapy. Before we had HER2 tyrosine kinase inhibitors (neratinib, lapatinib, tucatinib) and antibody-drug conjugates (trastuzumab emtansine, trastuzumab deruxtecan) for HER2+ breast canc...