1. Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, Fulham Road, London SW3 6JB, UK.
2. Breast Unit, Royal Marsden Hospital, Fulham Road, London SW3 6JJ, UK.
3. Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
4. Institute of Cancer Research Clinical Trials and Statistics Unit, The Institute of Cancer Research, 15 Cotswold Road, Surrey SM2 5NG, UK.