1. Department of Medical Oncology, Hospital Clínic, Barcelona, Spain
2. Department of Medicine, University of Barcelona, Barcelona, Spain
3. Division of Medical Oncology, Department of Medicine, Harvard Medical School, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Boston, MA, USA
4. Institut d'Investigacions Biomediques August Pi i Sunyer Barcelona, Barcelona, Spain
5. Medical Statistics Core Facility, IDIBAPS, (Hospital Clinic) Barcelona, Barcelona, Spain
6. Biostatistics Unit, Faculty of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain