Prognostic relavance of cerbB2 expression following neoadjuvant chemotherapy in patients in a randomised trial of neoadjuvant versus adjuvant chemoendocrine therapy

Recent advances in the detection and treatment of breast cancer have led to an intensive search for new markers of both prognosis and chemoresponsiveness. The oncogene cerbB2 has proved to be one of the most promising markers currently under study, both as a predictor of chemoresponsiveness and as a marker of poor prognosis. In addition the increasing use of neoadjuvant chemotherapy has led to the loss of standard prognostic criteria. In order to study the potential role of cerbB2 expression as an indicator of chemoendocrine resistance and poor prognosis, both before and after chemotherapy, we obtained tumour sections from 283 women enrolled onto a neoadjuvant trial. In this trial patients were randomised to receive either primary surgery followed by adjuvant chemoendocrine treatment or neoadjuvant chemoendocrine therapy followed by surgery. CerbB2 status was determined immunohistochemically on all of these patients. Thirty-eight percent of the tumours were cerbB2 positive. There was no significant difference in expression between the adjuvant (41%) and neoadjuvant arms (35%). CerbB2 positive patients were much more likely to have shown non-response to chemoendocrine therapy ( p <0.001) and had a worse DES ( p <0.05). The best prognosis was seen in cerbB2 negative patients receiving neoadjuvant chemoendocrine therapy who showed a significantly better DFS ( p <0.05), than the cerbB2 negative patients receiving adjuvant therapy.