Objective: Up-regulated expression or loss of expression of various carbohydrate antigens on the surface of cancer cells has been associated with a metastatic phenotype and poor survival in epithelial malignancies of different origins. The object of this study was to investigate the expression of carbohydrate antigens in two groups of patients diagnosed with advanced-stage ovarian carcinoma-one with an extremely favorable outcome and the other with a uniformly poor survival.
Methods: Sections from 76 paraffin-embedded blocks (primary ovarian carcinomas and metastatic lesions) from 45 patients diagnosed with advanced-stage ovarian carcinomas (FIGO stages III-IV) were immunohistochemically stained using five monoclonal antibodies for Lewis(y) (Le(y))(two antibodies), Sialyl Lewis(x) (Slex), Tn, and Sialyl Tn (STn) antigens. Patients were divided in two groups based on outcome. Long-term survivors (21 patients) and short-term survivors (24 patients) were defined using a double cut-off of 36 months for disease-free survival (DFS) and 60 months for overall survival (OS). Staining results for primary tumors and metastases were analyzed separately.
Results: Mean follow-up period was 70 months. The mean values for DFS and OS were 109 and 125 months for long-term survivors and 3 and 25 months for short-term survivors. Staining for all four antigens was seen in the majority of cases (range = 72-96%) and tended to be comparable in primary tumors and their metastases. However, absence of immunoreactivity for STn was seen in 9/38 (24%) metastatic lesions and only 1/38 (3%) primary tumors. This finding did not reach statistical significance (P > 0.05). A combined pattern of membranous and cytoplasmic staining was predominant in the majority of cases. Enhanced staining for Le(y) and STn was detected in the invasive front of some tumors, while Slex and Tn immunoreactivity did not relate to cell location. Primary tumors and metastatic lesions of long-term survivors displayed immunoreactivity patterns that were comparable to those of short-term survivors. In the evaluation of survival curves, more diffuse staining for Slex showed marginal correlation with poor survival (P = 0.05), while a trend toward poorer survival was seen in tumors that were more extensively stained for Le(y) and Tn (P > 0.05).
Conclusions: Le(y), Slex, STn, and Tn antigens are widely expressed in primary ovarian carcinomas and their metastases. Altered expression of Sialyl Tn is observed with tumor progression in a fraction of ovarian carcinomas. Expression of membrane carbohydrate residues is prevalent in tumors of both long-term and short-term survivors and does not appear to be a strong predictor of disease outcome. However, larger studies are needed to further elucidate the role of these molecules in ovarian carcinogenesis.
Copyright 2000 Academic Press.