C-ERBB-2 OVEREXPRESSION IN PRIMARY BREAST-CANCER - INDEPENDENT PROGNOSTIC FACTOR IN PATIENTS AT HIGH-RISK

The prognostic value of c-erbB-2 protein overexpression has been evalu ated in 463 patients with operable breast cancer after a median follow -up of 66 months. Overexpression was observed in 99/463 (21%) of the b reast tumors. It showed significant positive correlation to histologic al grade (p < 0.0001) and tumor size (p < 0.02). A relationship of bor derline significance was observed between c-erbB-2 protein overexpress ion and negative or low estrogen receptor (ER) content. No significant correlation was found to lymph node involvement or proliferating tumo r cell fraction as determined by the proliferating cell nuclear antige n (PCNA). After a median follow-up of 66 months (range 6 to 109 months ), the overall survival of all patients amounted to 63%. Multivariate analysis revealed lymph node involvement, tumor size, histological gra de, histological type, c-erbB-2 protein overexpression, progesterone r eceptor (PR) content, and oral contraceptive use as independent progno stic factors. In an univariate analysis, the overall survival amounted to 72% and 38% of tumor patients with negative and positive c-erbB-2 protein overexpression, respectively. The most significant finding is that c-erbB-2 overexpression has been recognized as an independent pre dictive factor in subsets of tumor patients who would be expected to h ave a generally poor prognosis, such as those indicating axillary lymp h node involvement, large tumor size ( > 2 cm), and PR negativity.