The Expression Of PS2, CD44V6 And MMP-9 In Gastric Carcinogenesis And Their Predictive Values For Lymph Node Metastasis

Aim To study the expression of PS2, CD44V6 and MMP-9 ingastric carcinogenesis and their predictive values for lymphatic metastasis.Method PS2, CD44V6 and MMP-9 expression were detected by Immunohistochemical (SP) method in 260 gastric mucosa tissues, including normal gastric mucosa (NOR), atrophic gastritis with midst or severe intestinal metaplasia (IM), with midst or severe dysplasia (DYS), early gastric cancer (EGC) (40 cases, each), and advanced gastric cancer (AGC)( 100 cases).Results In NOR, IM, DYS, EGC and ACG group, the positive immunostaining rates were 100%, 80.0%, 75.5%, 40.0% in and 65.0% in PS2; 0, 15.0%, 25.0%, 45.0% and 72.0% in CD44V6; 0, 40.0%, 50.0%, 40.0% and 68.0% in MMP-9, respectively. From group IM to DYS and EGC, the expression of PS2 was decreased gradually (P<0.05), the positive immunostaining rate in AGC group was higher than that in EGC group (P<0.05). From IM to DYS to EGC and AGC groups, CD44V6and MMP-9 expression were both increased ( T =0.512 and 0.245, respectively, P<0.05, respectively). None of the PS2, CD44V6 or MMP-9 expression in AGC showed correlation with gender, age, tumor location or size. In AGC group, PS2, CD44V6 and MMP-9 expression were higher in tumor tissues with full-thickness infiltrated or focus with lymph node metastasis than that in only muscularis externa infiltrated or no lymph node metastasis tissues; PS2 and MMP-9 expression were higher in diffuse-type than that in intestinal-type gastric cancer, while CD44V6 showed a reverse expression (P<0.05, respectively). In AGC group, concordance tendency was found between the expression of MMP-9 and CD44V6, or PS2 and CD44V6 , or PS2 and MMP-9 (P<0.05, respectively). As predictive markers for lymph node metastasis, the positive predictive values of PS2, CD44V6 and MMP-9 were 0.692, 0.681, and 0.691, respectively. In AGC tissues expressed all 3 markers, the rate of lymph node metastasis was 94.4%, higher than those expressed 1 (41.7%) or 2 of (68.0%) the 3 markers (P<0.05, respectively). In tissues expressed 2 of the 3 markers, the rate of lymph node metastasis was 68.0%, higher than those expressed 1 or none of the 3 markers (12.5%), (P<0.05, respectively). The rates of lymph node metastasis showed no significant difference between the AGC tissues expressed 1 and none of the 3 markers. For lymph node metastasis prediction, none of the 3 markers expression could achieve a negative predictive value in 0.875.Conclusion PS2, CD44V6 and MMP-9 expression play important roles in the gastric carcinogenesis, and can be taken as predictive markers for lymph node metastasis, especially when they are considered as combination markers.