Prognostic significance of E-cadherin and Cox 2 expression in Tunisian patients with colorectal mucinous adenocarcinoma.

Introduction: Mucinous colorectal carcinoma (MC) is a rare subtype of colorectal adenocarcinoma known to be associated with bad prognosis. Lately, research has turned to identify new prognostic markers allowing the use of targeted therapy. The aim of our study is to evaluate the prognostic impact of E-cadherin and Cox-2expression in MC.

Materials And Method: A total of 40 formalin-fixed, paraffin-embedded MC specimens were collected within a period of 13 years and were studied for the expression of the two proteins. We used SPSS 22 software to study associations with clinicopathological parameters and overall survival (OS).

Results: A reduced or absent E-cadherin expression was noted in 52.5% of cases. It was associated with distant metastases (p = 0.049) and venous invasion (p = 0.049). Cox-2 was overexpressed in 17.5% of cases. It was associated with negative lymph node status (p = 0.020) and with early stage tumor (p = 0.020). A significant association between the two proteins was also noted (p = 0.04). No significant association with OS was found; However, there was an improvement in the survival of patients overexpressing Cox-2 (p = 0.16).

Conclusion: Our findings link the loss of E-cadherin expression with spread and aggressiveness in MC and Cox-2 overexpression with better prognosis and survival. Because MC has a distinct genetic pathway we encourage the analysis of MSI and Cox-2 expression in all MC. Cox-2 inhibitors may not be effective chemopreventative agents in the setting of defective DNA mismatch repair. More molecular studies are needed to better understand the role of these markers and their prognostic significance in MC.