1. General Surgery Service, University Hospital Príncipe de Asturias, 28820 Alcalá de Henares, Spain
2. Medical Oncology Service, University Hospital Príncipe de Asturias, 28820 Alcalá de Henares, Spain
3. Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá de Henares, 28880 Alcala de Henares, Spain