Sialyl Tn antigen expression is associated with the prognosis of patients with advanced colorectal cancer

BACKGROUND/AIMS: One of the main problems in multimodal cancer treatment is the lack of prognostic parameters for the individual patient. This study was conducted to clarify the prognostic factors in patients with advanced colorectal cancer. METHODOLOGY: We examined DNA ploidy, Ki-67-derived growth fraction and the expression of CA 19-9, Sialyl Tn (STN) and carcinoembryonic antigens (CEA), along with standard clinicopathological variables including age, sex, tumor location, tumor size, cell differentiation, depth of invasion, and lymph node metastasis in 78 patients with advanced colorectal carcinoma, who underwent curative surgical resection. In addition, we determined the prognostic significance of these parameters. RESULTS: Forty-six patients (59.0%) showed aneuploidy and 32 (41.0%) showed diploidy. The Ki-67 labeling index ranged from 13.9-40.3% with a mean of 24.9%. The index was not correlated with standard clinicopathological variables. There was no significant correlation between seropositive rates for CEA, CA 19-9, or STN and standard clinicopathological variables except for age. In tumor tissue, the positive rates for these antigens were 62.8% for CA 19-9, 67.1% for STN, and 96.2% for CEA. There was no significant correlation between positive rates and clinicopathological variables. The expression of STN in serum had the strongest association with survival, followed by lymph node metastasis and expression of STN in tissue. CONCLUSIONS: We conclude that not only lymph node metastasis but also STN expression are important prognostic factors in patients with advanced colorectal carcinoma who undergo curative surgical resection.