1. Biometric Research Branch, National Cancer Institute, Bethesda, MD
2. Medical Statistics Group, Cancer Research UK, Centre for Statistics in Medicine, Wolfson College, Oxford, UK
3. Institut fuer Medizinische Biometrie und Medizinische Informatik, Universitaetsklinikum Freiburg, Freiburg, Germany
4. Cancer Diagonisis Program, National Cancer Institute, Bethesda, MD
5. Centro Regionale Indicatori Biochimici di Tumore, Ospedale Civile, Venezia, Italy
6. OSI Pharmaceuticals Inc, Boulder, CO