1. Danish Breast Cancer Cooperative Group (DBCG), Secretariat and Statistical Office, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark;
2. Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada;
3. Department of Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark;
4. Department of Surgical Pathology, Zealand University Hospital, Slagelse, Denmark;
5. Department of Pathology, Herlev University Hospital, Herlev, Denmark