Expression of MUC1 and MUC2 mucin gene products in human ovarian carcinomas

Background: Aberrations in expression of mucin glycoproteins have been observed during malignant transformation of human ovarian epithelium. To date, several secretory mucin genes designated the MUC gene family have been identified, of which MUC1 encodes a mammary-type and MUC2 an intestinal-type epithelial mucin. However, information on the expression and potential value of MUC1 and MUC2 mucins in ovarian cancer is limited. Methods: This study investigated immunohistochemical expressions of MUC1 and MUC2 mucins in 23 benign and 45 malignant human ovarian tumors to assess their clinicopathological relevance. Results: All benign serous tumors and also associated normal-appearing epithelia expressed MUC1 mucin on the cell surfaces. Benign mucinous tumors occasionally expressed MUC1 and MUC2 mucins. Most serous carcinomas (19/21; 90%) expressed MUC1 but not MUC2 mucin. Of the 16 mucinous carcinomas, 10 (62%) and five (31%) expressed MUC1 and MUC2 mucins, respectively. Four of the five clear cell and the three endometroid type carcinomas expressed MUC-1 but not MUC-2 mucin. A significant association was found between a high expression of MUC1 and histological grade (P = 0.005) and also disease stage (P = 0.001). Conclusion: These results suggest that a high expression of MUC1 may contribute to a poor prognosis in ovarian carcinoma.