Downregulated SASH1 expression indicates poor clinical prognosis in gastric cancer

SASH1 (SAM- and SH3-domain containing 1), a novel candidate tumor suppressor, has attracted attention due to its role in intracellular signal transduction and its tumor prognostic value in diverse cancers. Reports have demonstrated that reduced SASH1 expression correlates with tumor proliferation, invasion, and metastasis. However, the expression and prognostic significance of SASH1 in gastric cancer (GC) remain unclear. In this study, 8 paired fresh-frozen GC tissues and corresponding gastric mucosal tissues were examined by Western blot to analyze the protein expression of SASH1. Seven hundred twenty-six formalin-fixed, paraffin-embedded (FFPE) gastric tissue samples were evaluated by immunohistochemical (IHC) to determine the correlations of SASH1 expression with clinicopathological factors and prognosis. Compared with adjacent noncancerous tissues, SASH1 was significantly downregulated in GC specimens. Analysis using the χ² test revealed that low SASH1 expression was significantly associated with advanced TNM stage (P < .001) in GC. Cox regression multivariable analyses demonstrated that SASH1 expression (P < .001), TNM stage (P < .001), preoperative CEA level (P = .003) and preoperative CA19-9 level (P = .002) were independent prognostic factors. Our clinical findings suggest that downregulated SASH1 expression could be used as an independent biomarker for poor prognosis in GC.