A highly successful case report: a patient with intestinal hepatoid adenocarcinoma and liver metastases achieves excellent efficacy following immune-targeted therapy

Hepatoid adenocarcinoma (HAC) is a rare extrahepatic adenocarcinoma producing alpha-fetoprotein (AFP), with clinicopathological features resembling hepatocellular carcinoma, including aggressive behavior, poor prognosis, vascular invasion, and distant metastasis. It occurs mostly in the stomach and rarely in the colon. Due to its rarity, large randomized trials are lacking; thus, case reports provide valuable treatment information. Here, we report a 62-year-old woman initially diagnosed with massive hepatocellular carcinoma by computed tomography (CT) who underwent radical hepatectomy. Postoperative follow-up CT revealed lesions in the sigmoid colon and residual liver. Colonoscopic biopsy showed poorly differentiated carcinoma (adenocarcinoma with enteroblastic differentiation/hepatoid adenocarcinoma). She then received CAPOX (oxaliplatin plus capecitabine) combined with sintilimab and bevacizumab. After one year, follow-up imaging showed complete disappearance of the liver tumor and reduction of the sigmoid colon lesion. The final efficacy assessment was complete remission (CR) of the liver lesion and stable disease (SD) of the sigmoid colon lesion. This case report suggests that combined immune-targeted therapy and chemotherapy achieved excellent efficacy in a patient with intestinal hepatoid adenocarcinoma and liver metastases, and this combination regimen may provide a new treatment strategy for intestinal hepatoid adenocarcinoma (IHA).