Low CA II expression is associated with tumor aggressiveness and poor prognosis in gastric cancer patients.

Carbonic anhydrase II is present in normal gastric mucosa; thus, this study aimed to investigate whether its expression persisted in neoplastic gastric tissues, as well as its prognostic value for gastric cancer patients. The protein CA II expression pattern was retrospectively analyzed by immunohistochemistry in 181 gastric cancer patients who had undergone gastrectomy. The relationship between the CA II expression level and clinicopathological parameters was investigated. Survival analysis according to CA II expression was measured by Kaplan-Meier analysis. Univariate and multivariate Cox regression analyses were used to evaluate the prognostic value of CA II expression. CA II expression was significantly decreased in gastric cancer tissues compared with normal stomach mucosa. Low expression was significantly associated with tumor size, depth of invasion, lymph node involvement, distant metastasis and TNM stage, and it predicted poor survival in gastric cancer patients. Moreover, CA II was an independent prognosis indicator for the overall survival of gastric cancer patients. The down-regulation of CA II expression was observed in gastric cancer and may serve as an independent prognostic factor for the overall survival of gastric cancer patients.