Prognostic significance of c-erbB-2/neu amplification and epidermal growth factor receptor (EGFR) in primary breast cancer and their relation to estradiol receptor (ER) status

Abstract

The aim of this study is to evaluate the prognostic significance of c-erbB-2/neu amplification and epidermal growth factor receptor (EGFR) expression in primary breast cancer (BC) and their prognostic implications when combined with estradiol receptor (ER) status. In this work, 825 BCs were studied. Neu amplification was evaluated by dot-blot and EGFR expression was evaluated by ligand binding assay using I125-EGF. Neu, EGFR, estradiol and progesterone receptors (ER and PR) had a marked influence on disease free survival (DFS) in univariate analysis. In node-negative (NO) cases only neu was associated with short DFS (p = 0.005). However, in node-positive (N+) cases both EGFR (p = 0.005) and neu (p = 0.002) influenced DFS. None of the biological markers were significant predictors for overall survival (OS) in NO/BC. On the contrary, in N+/BC, EGFR + (p = 0.003) was associated with short OS. The EGFR + /neu/phenotype represented a sub-group with an even worse prognosis with respect to DFS (p = 0.0034) as well as EGFR + /ER-tumors (p = 0.005). Moreover, neu + /ER-patients also had a high probability of relapse (p = 0.0000) and death (p = 0.006). C-erbB-2/neu, EGFR, histological grade, pN, pT and ER were subjected to a Cox multivariate regression analysis: neu was the most important parameter in predicting recurrence, and EGFR was a significant predictor for OS.