Prognostic significance of Ep‐CAM AND Her‐2/neu overexpression in invasive breast cancer

Abstract

To assess the frequency and prognostic impact of Ep-CAM and Her-2/neu overexpression in patients with breast cancer and to determine its relationship with other prognostic markers, 205 breast cancer patients with a median follow-up of 10.8 years were enrolled in this retrospective study. Overexpression of Ep-CAM and Her-2/neu in tumor tissue samples was assessed by immunohistochemistry. Tumors presenting a Her-2/neu 2+ staining were additionally analyzed by FISH to exclude false positive results. Ep-CAM and Her-2/neu overexpression was found in 35.6% and 19.5% of the tumor samples, respectively. Both Ep-CAM and Her-2/neu overexpression were predictive for poor disease-free (DFS) and disease-related overall survival (DROS). Concurrent Ep-CAM and Her-2/neu overexpression was present in 13.2% of tumor specimens and had an additive negative impact on DFS and DROS. This minority of patients had a median time to relapse of only 34 months, whereas the median time to relapse was not reached in the patient population without Her-2/neu and Ep-CAM overexpression. By multivariate analysis Ep-CAM overexpression proved to be an indicator of poor prognosis, independent of tumor size, histologic grade, hormone receptor expression and Her-2/neu overexpression. In conclusion, overexpression of Ep-CAM and Her-2/neu complement each other as predictors for poor prognosis in patients with invasive breast cancer. Determination of these tumor markers should help in assigning breast cancer patients to 1 of 3 distinct risk categories.