2160 GIV as a novel marker of recurrence risk in MMR proficient stage II colon cancer

Abstract

s S387 Material and Methods: Formalin-fixed, paraffin-embedded tissue sections from 186 primary colorectal carcinomas and four normal colorectal tissues were immunostained using specific monoclonal antibodies against Tn and sialyl-Tn antigens. Baseline clinicopathological characteristics and overall 5-year survival were correlated with antigen expression. Results: Of the 186 colorectal carcinomas, Tn antigen is expressed in 70 (37.6%) and sialyl-Tn antigen is expressed in 141 (75.8%). There is no staining for these antigens in normal colorectal tissues. Immunostaining measurements for Tn antigen were significantly associated with the differentiation degree (p = 0.017) of the tumors, but independent of age, gender, tumor location, depth of penetration, status of lymph nodes, lymphovascular invasion, perineural invasion and TNM stage. The expression results of sialyl-Tn antigen revealed more significant associations with the degree of differentiation (p = 0.006) and perineural invasion (p = 0.041). The poor overall survival rate of patients was significantly associated with the positive expression of sialyl-Tn (p = 0.013) but not with the expression of Tn (p = 0.650). Survival at 5 years for patients with sialyl-Tn-negative versus sialyl-Tn-positive tumors was 72.1% versus 49.2%. Cox regression multivariate analysis confirmed that TNM stage (p = 0.001) and sialyl-Tn expression (p = 0.038) were the two most important variables of for predicting overall survival. Conclusions: These results indicate that Tn and sialyl-Tn antigens appear to be useful biomarkers of poorly differentiated adenocarcinomas and mucinous carcinomas. Moreover, the positive expression of sialyl-Tn antigen is an independent predictor of poor prognosis in human colorectal carcinoma. No conflict of interest.