Strong YB-1 expression is associated with liver metastasis progression and predicts shorter disease-free survival in advanced gastric cancer

Background The most significant cause of gastric cancer (GC) death is metastasis, although the underlying mechanisms remain obscure. Y-box binding protein-1 (YB-1) is associated with tumor aggressiveness and poor prognosis in various cancers. In this study we investigated the relationship between YB-1 expression and the clinicopathologic features and metastasis-associated epithelialmesenchymal transition (EMT) phenotype in advanced GC patients. Patients and Methods: Immunohistochemistry (IHC) was used to analyze YB-1, E-cadherin, and vimentin expression in 98 advanced GC cases. Results: Twenty-nine (29.6%) cases of GC exhibited strong YB-1 immunoreactivity. Strong YB-1 staining occurred more often in patients with intestinal or non-scirrhous cancer, and demonstrated a significant correlation with vascular invasion (VI), liver metastasis, and shorter disease-free survival (DFS). However, we observed no relationship between YB-1 expression and EMT phenotype or overall survival. Logistic regression analysis revealed that strong staining for YB-1 was the only predictive factor for liver metastasis. Conclusions: Our results indicate that YB-1 plays a role in the process of GC metastasis, and that the immunohistochemical detection of this protein potentially delivers valuable insight regarding the prediction of liver metastasis and shorter DFS in patients undergoing curative resection for advanced GC. J. Surg. Oncol. 2012; 105: 724-730. (C) 2012 Wiley Periodicals, Inc.