Slug and CD133 expression are associated with peritoneal carcinomatosis and survival in gastric cancer

Background: Slug is an activating transcription factor involved in epithelial-mesenchymal transition, and CD133 is a cancer stem cell marker found in various cancers, including gastric cancer (GC). We investigated the relationship between Slug and CD133 and the occurrence of peritoneal carcinomatosis and survival in patients with GC. Methods: This retrospective study included 196 patients with stage 2 or 3 GC who underwent curative surgery with D2 lymph node dissection and adjuvant chemotherapy between 2001 and 2009. We analyzed the expression of Slug, CD133, ABCG2, E-cadherin, vimentin, NEDD9, and SMAD4 in surgical tissue specimens using immunohistochemical analysis to determine their prognostic value. Results: Among the 196 patients, expression of Slug was elevated in 157 tumors (81%) while the expression of CD133 was high in 153 tumors (81%). The expression of Slug and CD133 in combination significantly predicted peritoneal relapse (P=0.002). High Slug and high CD133 expression were significantly associated with poor peritoneal relapse-free survival [hazard ratio (HR), 7.239; P=0.007] and overall survival (HR, 1.682; P=0.027) in multivariate Cox analysis. Conclusions: Our study shows that a high Slug and high CD133 expression status is predictive of peritoneal recurrence in high-risk resected GC patients. They are also a poor prognostic factor for peritoneal relapse-free survival and overall survival.