Expression of Tn and sialyl-Tn antigens in endometrial cancer: its relationship with tumor-produced cyclooxygenase-2, tumor-infiltrated lymphocytes and patient prognosis.

BACKGROUND: Although many tumors arising from epithelial tissues produce mucins, little is known regarding the biological significance of mucins in cancer. Recent researches have revealed that mucins produced by cancer cells play a critical role in the initial induction of cyclooxygenase (COX)-2 in the tumor microenvironment. Moreover, the consequence of abnormal glycosylation and overexpression of mucins includes suppression of the host-immune function.

MATERIALS AND METHODS: The expression of Tn/sialyl-Tn (s-Tn) antigen and its impact on COX-2 expression by tumor cells and infiltration of CD8+ T-cell into the cancer cell nest (nest CD8) in endometrial cancer was evaluated. Tissue specimens from 70 endometrial cancer patients who had undergone a curative resection were evaluated for Tn/s-Tn antigen, COX-2 and CD8 by immunohistochemistry.

RESULTS: The overexpression of Tn and s-Tn antigen was significantly correlated with COX-2 overexpression (p <0.005 and p <0.001, respectively). There was a significant association between s-Tn overexpression and low infiltration of nest CD8 (p<0.05). Strong expression of s-Tn antigen was significantly associated with poor prognosis (p < 0. 005). Among several prognostic factors, s- Tn expression remained the strong independent predictor of survival by multivariate analysis (p<0.05).

CONCLUSION: These results suggested that tumor-produced mucins, which were associated with COX-2 induction and immunosuppression, provided additional prognostic information in endometrial cancer patients.