Inclusion Criteria:  Patient of 18 years and more Patient of the Orthopedic and Traumatological Surgery Department of the Reims University Hospital or the Godinot Institute Patient with osteosarcoma or chondrosarcoma to be operated on regardless of stage. Patient agreeing to participate in the study (informed consent form) Patient fluent in French Patient affiliated with a social security regimen  Exclusion Criteria:  Patient having a medical history that may compromise the protocol (psychiatric, medical or pharmacological disorders such as the use of anti-inflammatory drugs, or any compound that may alter or modify the inflammatory reaction in the week preceding the protocol). Pregnant or breastfeeding women Patient with eating disorders (anorexia, bulimia, overeating) Patient protected by law (guardianship, curatorship, hospitalized without their consent and not protected by law, deprived of liberty)