Micrometastases or Isolated Tumor Cells and the Outcome of Breast Cancer

From the Division of Medical Oncology, Maastricht University Medical Center, Maastricht (M.B., V.C.G.T.-H.); Comprehensive Cancer Center East (M.B., J.A.A.M.D.) and the Divisions of Epidemiology, Biostatistics, and HTA (J.A.A.M.D., G.F.B., E.M.M.A.) and Pathology (P.B.), Radboud University Nijmegen Medical Center, Nijmegen; the Division of Pathology, University Medical Center Utrecht, Utrecht (C.H.M.D., P.J.D.); the Division of Medical Oncology, Leiden University Medical Center, Leiden (J.W.R.N.); the Division of Surgery, the Netherlands Cancer Institute, Amsterdam (E.J.T.R.); and the Divisions of Medical Oncology (C.S.) and Surgery (M.B.E.M.-P.), Erasmus Medical Center–Daniel den Hoed Cancer Center, Rotterdam — all in the Netherlands. Address reprint requests to Dr. Tjan-Heijnen at the Division of Medical Oncology, Department of Internal Medicine, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, the Netherlands, or at [email protected].