The preferred second-line therapy regimens include ramucirumab and paclitaxel, fam-trastuzumab deruxtecan-nxki for HER2 over expressive positive adenocarcinoma, docetaxel, paclitaxel, irinotecan, fluorouracil and irinotecan, and trifluridine and tipiracil for third-line or subsequent therapy. This evidence concerns the gene ERBB2 and adenocarcinoma.