Prognostic value of c-erbB2 expression in breast cancer

BACKGROUND AND OBJECTIVES: An overexpression of c-erbB2 has been reported to be associated with a poor clinical outcome in breast cancer, however, its prognostic value remains controversial especially in patients with node negative breast cancer, and regarding the estrogen receptor (ER) status. METHODS: Immunohistochemical staining for c-erbB2 was performed on the primary breast cancer from 698 Japanese patients with a mean follow-up duration of 54 months. RESULTS: The c-erbB2 expression was positive in 120 (17.2%) of 698 cases, which inversely correlated with the ER status. Both univariate and multivariate analyses indicated the c-erbB2 expression to be a significant prognostic factor for the disease-free survival (DFS) and overall survival (OS), while the same effect was also seen in the patient groups with node negative as well as node positive breast cancer. A univariate analysis also indicated a subgroup with the positive c-erbB2 and negative ER to have both a worse DFS and OS than the other subgroups. The patients with positive c-erbB2 had a significantly worse DFS and OS than the patients with negative c-erbB2 in all patient groups stratified according to the adjuvant therapies, while the prognostic significance of c-erbB2 on DFS was also found in the patients with the node negative breast cancer who received adjuvant tamoxifen alone. CONCLUSIONS: The c-erbB2 expression is an independent significant factor for breast cancer and the prognostic significance remains in the node negative as well as node positive breast cancer, while the same effect was also found in all subgroups stratified according to the adjuvant therapies. In addition, the combination of c-erbB2 and ER made it possible to identify the subgroup with the worst clinical outcome.