The Potential Role of Radiotherapy in the Management of Hepatoid Carcinomas of the Stomach: A Case Report

Pathologic complete response of hepatoid adenocarcinoma of the stomach after chemo-immunotherapy: A rare case report and literature review

Background

Hepatoid adenocarcinoma of the stomach (HAS) is a highly malignant subtype of gastric carcinoma with specific clinicopathological features and extremely poor prognosis. We present an exceedingly rare case of complete response after chemo-immunotherapy.

Case Description

A 48-year-old woman with highly elevated serum alpha-fetoprotein (AFP) level was found to have HAS verified by pathological examination based on gastroscopy. Computed tomography scan was done and TNM staging of the tumor was T4aN3aMx. Programmed cell death ligand-1 (PD-L1) immunohistochemistry was performed, revealing a negative PD-L1 expression. Chemo-immunotherapy including oxaliplatin plus S-1 and PD-1 inhibitor terelizumab was given to this patient for 2 months until the serum AFP level decreased from 748.5 to 12.9 ng/mL and the tumor shrank. D2 radical gastrectomy was then performed and histopathology of the resected specimen revealed that the cancerous cells had disappeared. Pathologic complete response (pCR) was achieved and no evidence of recurrence has been found after 1 year of follow-up.

Conclusions

We, for the first time, reported an HAS patient with negative PD-L1 expression who achieved pCR from the combined chemotherapy and immunotherapy. Although no consensus has been reached regarding the therapy, it might provide a potential effective management strategy for HAS patient.

Carcinosarcoma of the stomach with alpha-fetoprotein-producing hepatoid adenocarcinoma: an unexpected combination of two rare subtypes of gastric cancer in one tumor

Carcinosarcoma is a rare malignant neoplasm comprising both epithelial and mesenchymal components. Hepatoid adenocarcinoma (HAC) is another rare type of cancer. To date, there are only four reported cases of concurrent carcinosarcomas with HAC across all tumor types, all of which were observed in uterine tumors. Here, we report an unusual case of gastric carcinosarcoma associated with alpha-fetoprotein (AFP)-producing HAC in a 76-year-old woman. Upon admission, the patient had an elevated serum AFP concentration (448 µg/L), a necrotic polypoid tumor of the central gastric cardia revealed by endoscopy, and no evidence of distant metastasis indicated by computed tomography (CT). Owing to malignancy indicated by biopsy, the patient underwent proximal subtotal gastrectomy. The resected tumor was composed of both an HAC component and a sarcoma component, microscopically. The sample was positive for AFP, hepatocyte paraffin (Hep-Par) 1, glypican-3, SALL4, CDX2, cytokeratin (CK) (pan), CK18, desmin, and vimentin staining immunohistochemically. In summary, the tumor was diagnosed as carcinosarcoma of the stomach with AFP-producing HAC. To our knowledge, this is the first report of gastric carcinosarcoma with AFP-producing HAC in the English literature describing gastric tumors.

Hepatoid Adenocarcinoma of the Stomach: Current Perspectives and New Developments

Hepatoid adenocarcinoma of the stomach (HAS) is a rare malignant tumor, accounting for only 0.17-15% of gastric cancers. Patients are often diagnosed at an advanced disease stage, and their symptoms are similar to conventional gastric cancer (CGC) without specific clinical manifestation. Morphologically, HAC has identical morphology and immunophenotype compared to hepatocellular carcinoma (HCC). This is considered to be an underestimation in diagnosis due to its rare incidence, and no consensus is reached regarding therapy. HAS generally presents with more aggressive behavior and worse prognosis than CGC. The present review summarizes the current literature and relevant knowledge to elaborate on the epidemic, potential mechanisms, clinical manifestations, diagnosis, management, and prognosis to help clinicians accurately diagnose and treat this malignant tumor.