Prognostic contribution of the HER-2 oncogene overexpression to the Nottingham Prognostic Index in breast cancer

The Nottingham prognostic index (NPI) is a widely adopted prognostic tool in breast cancer. The HER-2 oncogene overexpression is also associated with higher risk. The aim of our study is to investigate the correlation between the NPI and HER-2 in breast cancer. Two hundred and five patients with breast cancer managed in the Department of Surgery, University of Hong Kong Medical Centre, at Queen Mary Hospital between January 1995 and December 1997 were studied. This is a retrospective analysis of prospectively collected database. Variables evaluated for the analysis of prognostic significance included tumor size, axillary lymph node status, histological grade, estrogen and progesterone receptor status and HER-2 oncogene expression. NPI was calculated from tumor size, lymph node status and histological grade. In univariate analysis, tumor size, axillary lymph node status, distant metastasis status, HER-2 oncogene overexpression and NPI score were found to be significant variables. Significant poorer overall survival was also observed with higher NPI category and positive HER-2. Only tumor size and NPI category with subdivision by HER-2 status were independent factors in multivariate analysis . The combination of the HER-2 oncogene expression status with the widely adopted NPI provides a reliable way to predict prognosis in breast cancer patients.