Prognostic value of the combination of epidermal growth factor receptor and c-erbB-2 in breast cancer

BACKGROUND: Epidermal growth factor receptor (EGFR) and c-erbB-2 are 2 of the 4 members of the erbB receptor family that play a role in signaling by forming heterodimers between family members. METHODS: The immunohistochemical expression of EGFR and c-erbB-2 was determined on 670 women who underwent operation for primary breast cancer. RESULTS: According to the combination of EGFR and c-erbB-2, 670 patients were classified into 4 groups: EGFR(-)/c-erbB-2(-) (417 patients); EGFR(+)/c-erbB-2(-) (136 patients); EGFR(-)/c-erbB-2(+) (72 patients); and EGFR(+)/c-erbB-2(+) (45 patients). Univariate analyses on disease-free and overall survival showed a significant difference among these 4 groups, whereas the difference between patients with positive and negative expression of EGFR was not statistically significant in patients with positive expression of c-erbB-2. A multivariate analysis indicated the combination of EGFR and c-erbB-2 to be an independently significant prognostic factor for disease-free and overall survival. CONCLUSIONS: Breast cancer with both a positive EGFR and c-erbB-2 expression had the worst prognosis, whereas the prognostic value of c-erbB-2 was stronger than that of EGFR in breast cancer.