Cytokeratin 7/20 Expression Patterns and Association with Prognostic Varia- Bles in Gastric Adenocarcinomas

Aim: The histologic features, potential behavior, genetic pathways, epidemiological characteristics and response to treatment of gastric carcinomas, is showing heterogeneity. Cytokeratin (CK), an intermediate-sized filament detected primarily in epithelial cells. Most commonly used CKs in immunohistochemical studies are CK7, CK20 and these molecules are used as a markers to help identify the site of origin of metastatic carcinomas. The aim of this study to evaluate the expression pattern of CK7 and CK20 molecules in primary adenocarcinoma of the stomach and their relation between clinicopathologic prognostic factors. Material and method: Gastric adenocarcinoma specimens were obtained from 103 patients who underwent total / subtotal gastrectomy with extended lymphadenectomy between December 2011-December 2013. Results: The 103 gastric adenocarcinomas included 80 (77.60%) cases with CK7 expression and 56 (54.30%) cases with CK20 expression, and were classified into 4 (3.80%) cases with CK7-/CK20 pattern, 43 (41.70%) cases with CK7+/CK20 pattern, 19 (18.40%) cases with CK7-/CK20+ pattern and 37 (36.10%) cases with CK7+/CK20+ pattern. CK expression patterns was not associated with additional variables which were age, gender, tumor location, size, depht of invasion, lymphatic and perineural invasion, lymph node and distal organ involvement, existence of H. pylori and intestinal metaplasia, histological type according to Lauren classification system and p53 expression. Conclusion: The CK expression patterns cannot helpful in determining prognostic factors for gastric adenocarcinoma.