Clinicopathological features of hepatoid adenocarcinoma and non‐hepatoid adenocarcinoma of the stomach: A systematic review and meta‐analysis

Abstract Background Hepatoid adenocarcinoma of the stomach (HAS) is an extremely rare and unique malignant gastric tumor with a significantly worse prognosis than non‐hepatoid adenocarcinoma of the stomach (non‐HAS). The present study explored the clinicopathological features of HAS and non‐HAS patients to provide insights into HAS treatment strategies. Methods From December 26, 2023, we performed a comprehensive search of the PubMed, Web of Science, Cochrane Library, and Embase.com databases for relevant studies. Two authors independently screened the studies, evaluated their quality, extracted data, and performed the analyses. This study was registered with PROSPERO on January 2, 2024. Results Nine retrospective studies were included for analysis after screening 833 articles. A total of 350 and 924 patients were enrolled in the HAS and non‐HAS groups, respectively. While no significant differences were observed in age, sex, tumor size, T3 or T4 stage, and N2 or N3 stage between the two groups, the HAS group exhibited higher rates of lymph node metastasis (OR = 1.93, 95% CI: 1.19–3.13, p = 0.007), liver metastasis (OR = 3.45, 95% CI: 2.26–5.28, p < 0.001), and vascular invasion (OR = 2.76, 95% CI: 2.05–3.71, p < 0.001). Additionally, the HAS group had lower 3‐year survival rates (HR = 2.35, 95% CI: 1.70–3.25, p < 0.001) and 5‐year survival rates (HR = 3.63, 95% CI: 1.49–8.88, p = 0.005), but lower rates of lymphatic permeation (OR = 0.68, 95% CI: 0.47–0.99, p = 0.040). Conclusion Based on the current clinical evidence, patients with HAS present distinct clinicopathological features, greater invasiveness, and poorer prognosis than non‐HAS patients. Further research is warranted to develop optimal treatment strategies for HAS.