Glasgow, UK: Genetic analyses of results from 1125 postmenopausal women being treated for oestrogen responsive breast cancer have shown that some of them are more likely than others to have a late recurrence of their cancer and might benefit from ten years of hormone therapy rather than five.
Prof Mitch Dowsett told the opening press conference at the European Breast Cancer Conference (EBCC-9) that his research had shown that women who had tumours that were negative for the human epidermal growth factor protein (HER2-) but which were very sensitive to the oestrogen hormone, had more than double the risk of their cancer recurring between five and ten years after surgery and five years of adjuvant hormone therapy.
"Our data suggest that these patients, who are those that appear to benefit most from the current standard five years of endocrine treatment, may also benefit from adjuvant hormone treatment that extends beyond that five years," said Prof Dowsett, who is Professor of Biochemical Endocrinology at The Institute of Cancer Research, London, UK, and Head of Biochemistry at The Royal Marsden NHS Foundation Trust, London. The work is a collaboration between his team and that of Professor Jack Cuzick at the Wolfson Institute of Preventive Medicine, Queen Mary University of London, UK.
The findings are the latest to come from the ATAC trial (Arimidex, Tamoxifen Alone or in Combination), a double-blinded phase III clinical trial that randomly assigned postmenopausal women with early, oestrogen receptor positive (ER+) breast cancer to receive the hormone therapies anastrozole or tamoxifen, or a combination of the two. 
Prof Dowsett and his colleagues at The Royal Marsden, The Institute of Cancer Research and Queen Mary University of London used data from the OncotypeDx 21-gene Recurrence Score that are not usually available from this test in order to analyse the genetic make-up and to predict the likelihood of cancer recurrin
|Contact: Emma Mason|
ECCO-the European CanCer Organisation