P1-HNF4α expression negatively correlates with HER2 levels and is associated with good prognosis in gastric adenocarcinoma.

: HNF4α, a member of the steroid/thyroid nuclear receptor super family, is a transcriptional factor expressed in various tissues and cells. In this study, we aimed to investigate the clinical significance of P1-HNF4α protein expression in gastric adenocarcinoma. We examined P1-HNF4α and HER2 protein levels in the tissue of 245 gastric adenocarcinoma samples by immunohistochemistry, and analyzed the association between P1-HNF4α levels, and clinicopathologic factors or prognosis. In gastric adenocarcinoma, positive staining of P1-HNF4α was shown in 150 (61.2%) of 245 cases, while positive expression of HER2 was shown in 36 (14.7%) of 245 cases as detected by immunohistochemistry. The expression of P1-HNF4α was negatively correlated with that of HER2. Furthermore, P1-HNF4α and HER2 highly expressed in intestinal-type adenocarcinoma according to the Lauren classification, tubular adenocarcinoma according to WHO classification, and well-to-moderately differentiated tumors. In gastric adenocarcinoma, P1-HNF4α was significantly associated with histological type, Lauren grade, degree of tumor differentiation, vascular invasion, lymph node metastases, and pTNM stage. Moreover, survival analysis showed that P1-HNF4α expression was an independent prognostic factor of good survival in gastric adenocarcinoma (P<0.05). Our results indicate that a negative correlation exists between P1-HNF4α and HER2 expression levels and P1-HNF4α is significantly correlated with tumor progression and a good prognosis in gastric adenocarcinoma.