Canonical and noncanonical Wnt pathway: a comparison among normal ovary, benign ovarian tumor and ovarian cancer.

The Wnt family is involved in tumorigenesis of several tissues. In ovarian cancer, the role played by Wnts and its pathways is not clearly defined. In order to analyze the canonical and noncanonical Wnt pathway in normal ovary, benign ovarian tumor and ovarian cancer, we evaluated the immunohistochemical expression of Wnt1, Frizzled-1 (FZD1), Wnt5a, Frizzled-5 (FZD5) and beta-catenin. Ovarian specimens were obtained from surgeries performed between 1993 and 2004. The patients were divided in three groups: group A, epithelial ovarian cancer (n=38); group B, benign epithelial neoplasia (n=28); and group C, normal ovaries (n=26). Immunoreactivity for Wnt1, FZD1, Wnt5a, FZD5 and beta-catenin was scored for each group. The proportion of Wnt1 positive women in group A (29.4%) was significantly higher than in group B (4.3%) and C (9.1%) (p=0.020). The proportion of FZD1 positive patients in group C (54.5%) was significantly lower than in group A (97.1%) and B (90.0%) (p<0.001). The proportion of Wnt5a positive women was significantly higher for group A (80.0%) compared to group B (25.0%) and C (27.3%) (p<0.001). The proportion of beta-catenin positive patients in group C (95.8%) was significantly higher than group B (52.4%) (p=0.004). Comparison of the survival curves in group A according to Wnt5a expression showed a significant difference between positive and negative patients, whereas the Wnt5a positive women showed worse results (p=0.050). Our findings suggest that the pathways related to Wnt5a have an important role in ovarian malignant neoplasia. Furthermore, Wnt5a was found to be a predictor of poor prognosis for ovarian cancer.

Analysis of the expression of estrogen receptor, progesterone receptor and chicken ovalbumin upstream promoter-transcription factor I in ovarian epithelial cancers and normal ovaries.

Sex hormones are involved in the carcinogenesis of some gynecologic cancers, and the status of their receptors represents an indicator of prognosis and of the therapeutic response in breast and endometrial cancers. In the ovary, this role is not clearly defined, with epithelial cancers being poorly responsive to hormone therapy. COUP-TFI (chicken ovalbumin upstream promoter-transcription factor I) is an orphan nuclear receptor, which is expressed in various tissues and regulates the estrogen receptor (ER) by competition for DNA binding. To investigate the role of these receptors in ovarian carcinogenesis and their implications for cancer prognosis, we evaluated the immunohistochemical expression of ER, progesterone receptor (PR) and COUP-TFI in benign and malignant ovarian epithelial neoplasms and in normal ovaries. A total of 113 ovarian specimens, including 40 diagnosed as malignant epithelial neoplasms (group A), 45 as benign epithelial tumors (group B), and 28 from normal ovaries (group C) were analyzed. Immunoexpression of ER was observed in 70% of patients of group A, 57.8% of group B and 57.1% of group C, with no significant difference between groups (p=0.426). Immunoexpression of PR was significantly lower in group A (12.5%) compared to group B (42.2%) and group C (32.1%) (p=0.010). Similarly, COUP-TFI was expressed in only 10% of group A patients, a rate significantly lower than that observed for group B (31.1%) and group C (39.3%) (p=0.014). No association was observed between the expression of these markers and increased survival or clinical prognostic variables. Multivariate analysis revealed a residual tumor <1 cm as the most significant clinical prognostic factor in group A (p=0.010, OR=4.14). These data support the importance of cytoreduction in the treatment of ovarian cancer, the role of steroid receptors in the mechanism of carcinogenesis, and the need for selection of subgroups that may respond to hormone therapy.