Expression of CA125 in tissue and serum of uterine serous carcinoma patients

Abstract

Joseph Menczer, Letizia Schreiber, Esther Berger, Tally Levy

Objective: To compare tissue immunohistochemical expression of CA125 with its level in the serum of corresponding uterine serous carcinoma (USC) patients. Materials and Methods: Paraffin-embedded tissue blocks of consecutive USC uterine specimens of 25 patients with known serum CA125 levels prior to treatment were examined. The clinicopathological records of these patients were retrospectively abstracted. Immunohistochemistry was performed in each case on deparaffinized 4μ sections of paraffin-embedded tissue blocks for detection of CA125. Staining of more than 10% of cells was considered positive. A scoring index was calculated by multiplying the intensity grade by the percentage of stained cells and considered low when it was equal to 1 or less and high when it was more than 1. Results: Positive immunohistochemical staining and a high staining score were found in 72.0% and 61.1% of the patients respectively elevated serum CA125 levels prior to treatment were observed in 36.0% of the patients. The difference between the percentage of USC patients with positive CA125 tissue staining and the percentage of those with elevated CA125 serum levels were significant. Elevated serum levels correlated significantly with advanced stage disease. No correlation was found between positive immunohistochemical tissue staining parameters and stage of the disease. Conclusion: The higher proportion of USC patients with positive CA125 immunohistochemical tissue staining than with elevated serum CA125 levels indicates the presence of some mechanism that prevents the access of CA125 into the circulation.