Purpose: A clinical trial that evaluated the efficacy of Herceptin® (anti-erbB2 antibody) as a first-line therapy for metastatic breast cancer was presented. It was demonstrated that 38% of the metastatic breast cancer
patients
benefited clinically from the Herceptin therapy. Recently, a trial of systemic chemotherapy was recommended as a first-line treatment for the patient with metastatic breast cancer refractory to Herceptin therapy. Therefore, it is necessary to
evaluate
c-erbB-2 protein expression in breast cancer prior to Herceptin treatment and the significance of c-erbB-2 protein as a prognostic predictor.
Methods: To evaluate c-erbB-2 protein as a prognostic predictor, we analyzed the expression of c-erbB-2 protein by the immunohistochemical method in comparison with other factors such as age, tumor size, stage, histologic grade, LN status,
hormonal receptor status and DNA ploidy. Then we performed survival analysis. A total of 266 patients who underwent mastectomy between May 1998 and April 2000 were evaluated and statistical significance was determined by χ2 test.
Results: In 146 of the 266 patients (54.9%) c-erbB-2 was positive in the tumor, and negative in the remaining 120. The overexpression of c-erbB-2 was positively correlated with tumor size and progesterone receptor positivity. The c-erbB-2
expression showed an association with a low recurrence-free survival probability in univariate analysis (P=0.0159). However, in multivariate analysis, c-erbB-2 expression was not an independent prognostic factor.
Conclusions: The c-erbB-2 protein expression appears to have prognostic significance in breast cancer but long-term follow-up studies are necessary for confirmation.
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