Combination of interferon and tamoxifen for patients with advanced breast cancer and negative oestrogen receptors

Oestrogen receptor (ER) levels are important predicators of prognosis and response to therapy in breast cancer. Patients with ER positive tumours respond to endocrine therapy at a significantly higher rate than those with negative ER tumours. In this study, 19 metastatic breast cancer patients with negative ER tumours were treated with interferon (IFN) β+γ and tamoxifen. Within the study group, there was an objective overall response rate of 39%, while another 28% demonstrated stabilization of their metastatic disease: a result we describe as encouraging. Further large phase III randomized studies are needed to assess the potential of the combination of IFNs and tamoxifen in improving the response rate and survival in breast cancer patients.