The expression of Claudin-4 in gastric cancer tissue: A single center experience.

PURPOSE: Gastric cancer (GC) is still one of the most common malignancies with the majority of the tumors diagnosed at advanced stage. The need for identification of prognostic and early detection biomarkers is thus compulsory. Claudins are biomarkers that are currently evaluated in the literature in the frame of epithelial-mesenchymal transition. The purpose of this investigation was to study the expression of claudin-4 in the various histological subtypes of GC and to evaluate its prognostic value.

METHODS: This investigation was performed on gastric tumors obtained from 66 (46 men and 20 women) patients with documented gastric adenocarcinoma who underwent total or partial gastrectomy and regional lymphadenectomy from 2003 till 2011. Features such as tumor size, depth of invasion, grade and histological subtype, lymphovascular space invasion and regional lymph nodes involvement were also evaluated. Immunohistochemistry (IHC) was used for assessing the expression of claudin-4 with a semi-quantitative model.

RESULTS: 66.7% of our cases showed abnormal claudin-4 expression in IHC. Claudin-4 was significantly correlated with tumor T stage and with intestinal type classification. The correlation of claudin-4 tissue expression with patient overall survival survival (OS) or disease-free survival (DFS) was not statistically significant, as well as with age, gender, tumor N stage, grade, TNM stage, positive lymph node ratio or lymphovascular invasion.

CONCLUSIONS: Literature stands equivocal about the exact role and prognostic value of claudin-4 and histopathology and tumor invasiveness in patients with GC. Our results further strengthen the need of larger studies to fully elucidate the predictive role of claudin-4 in the natural history of GC.