1. Memorial Sloan Kettering Cancer Center; New York NY U.S.A.
2. Division of Translational Research and Applied Statistics, Department of Public Health Sciences; University of Virginia; Charlottesville VA U.S.A.
3. Department of Biostatistics; Columbia University; New York NY U.S.A.
4. Department of Biostatistics, MD Anderson Cancer Center; University of Texas; Austin TX U.S.A.
5. LSTA; Université Pierre et Marie Curie, Paris VI; Paris 75005 France