Treatment of breast cancer with trastuzumab deruxtecan versus trastuzumab emtansine: In collation with trastuzumab emtansine, trastuzumab deruxtecan is linked with a reduced likelihood of disease progression or fatalities among individuals who have positive HER2 cancer of the breast who had formerly received trastuzumab along with a taxane treatment. This evidence concerns the gene ERBB2 and breast cancer.