Aberrant β-catenin activity in hepatoid adenocarcinoma of the stomach
Background: Hepatoid adenocarcinoma of the stomach (HAS) has been recognized as a rare primary gastric tumor characterized by hepatocellular carcinoma-like histology. HAS often causes diagnostic confusion with conventional gastric adenocarcinoma (CGA) due to the difficulty to detect hepatoid differentiation solely based on findings from hematoxylin and eosin (H&E) staining. Hence, HAS should be distinguished from solid-type CGA based on their different biological behaviors. β-catenin is highly expressed in hepatocellular carcinoma (HCC), which is involved in the maintenance of tumor initiating cells, drug resistance, tumor progression, and metastasis. Methods and Results: Given the dearth of HAS cases, systematic examination of the expression of β-catenin in HAS remains under-explored. In this study, 14 cases were subjected to immunostaining with with AFP, β-catenin, glypican3, hepar-1 and CerbB-2. In parallel, the clinicopathological characteristics of these patients were collected. We detected statistically significant difference in the expression of β-catenin (P = 0.000), glypican3 (P = 0.019), and hepar-1 (P = 0.007) between HAS cancer tissues and the adjacent non-cancerous tissues. Furthermore, a significant correlation was observed between the expression of β-catenin in HAS cancer tissue and adjacent tissue (Pearson correlation coefficient: 0.686, P = 0.007). Moreover, in cancer tissues, a significant correlation was observed between the expression of β-catenin and survival time (Spearman correlationcoefficient= - 0.482, P = 0.003). However, we found the expression of β-catenin did not correlate with the degree of tumor differentiation and tumor size, age, gender, serum AFP levels, microinvasion, and metastasis (P > 0.05). Conclusion: Our findings establish β-catenin as a useful marker that can distinguish HAS from CGA and may improve the early diagnosis to guide the appropriate and timely treatment of HAS patients.