Colorectal cancer (35)December 2018: dx with stage 4 ascending colon cancer with liver metastases (ERBB2 negative, RAS mutated; staging scans reveal synchronous breast cancer)Treated with FOLFOXIRI (+trastuzumab), then hepatectomy (with concurrent mastectomy), followed by FOLFOXIRI (+trastuzumab and tamoxifen)October 2019: recurrence to lung and liver with subsequent progression on all further lines of therapy. This evidence concerns the gene ERBB2 and breast cancer.