EpCAM-autoantibody levels in the course of disease of ovarian cancer patients

Abstract

EpCAM is a tumor-associated antigen, which is frequently expressed in ovarian cancer. Recently, autoantibodies against EpCAM have been identified in patients with ovarian cancer. It is not clear whether these autoantibodies are of prognostic importance. We evaluated whether EpCAM-autoantibodies have an impact on the clinical course of patients with ovarian cancer. EpCAM-autoantibodies were determined in sera of 28 healthy voluntary age-matched women and 84 patients with primary epithelial ovarian cancer before and after platinum-based chemotherapy using a recombinant EpCAM-protein for antibody detection by ELISA technique. The median follow-up time was 18 months. Samples exceeding the mean antibody titer of healthy controls plus 2 standard deviations were considered positive. The antibody titer of healthy controls was 0.061 ± 0.015. Using a cut-off value of 0.091, we found 3/84 (4%) patients before and 12/61 (20%) patients with ovarian cancer to be positive for EpCAM-autoantibodies after first-line treatment. Using the paired T-Test, we noted a significant post-therapeutic increase of AABs (P < 0.0001). Notably, AAB-levels after first-line therapy were found to be correlated with the tumor resection status in primary surgery. Analysis of progression-free survival, FIGO stage, grading, age and sensitivity to platinum-based chemotherapy did not reveal significant associations with EpCAM-AAB titers. We observed an increase in AAB-levels during the first-line treatment of patients with ovarian cancer. EpCAM-AAB-levels after first-line treatment appear to correlate with macroscopic tumor residuals after initial surgery.