- Collection of epidemiological data: age, medical and surgical history (cardiac insufficiency, renal insufficiency, respiratory insufficiency, COPD, coronary artery disease), ethyl intoxication (gram / day), tobacco poisoning (package / year), usual treatment, tumor characteristics for group K+ (histological type, location, tumor stage, nature of treatment), indication and nature of surgery for group K-, pre-operative renutrition program for K + group (food supplements, enteral or parenteral feeding )