Andres Cervantes1,2, George Pentheroudakis3,4, Dirk Arnold5,6. 1. Guidelines Committee Chair, European Society for Medical Oncology, Viganello-Lugano, Switzerland. 2. Department of Hematology and Medical Oncology, Institute of Health Research Hospital Clinic of Valencia (INCLIVA), University of Valencia, Valencia, Spain. 3. Guidelines Committee Co-Chair, European Society for Medical Oncology, Viganello-Lugano, Switzerland. 4. Department of Oncology, University of Ioannina Medical School, Ioannina, Greece. 5. Guidelines Committee, Subject Editor for Gastrointestinal Cancer, European Society for Medical Oncology, Viganello-Lugano, Switzerland. 6. Hubertus Wald Tumor Center, University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.