Observational retrospective cohort study using laboratory data of blood tests prior to surgical and chemotherapy treatment and other histologic, clinical, and instrumental data related to patient history from digitized medical records and analysis of the same as predictors of outcomes.

Inclusion Criteria:

• Osteosarcoma diagnosed at the Pathological Anatomy of the Rizzoli Orthopaedic Institute in Bologna;
• Minimum 2-year follow-up period;
• Medical records, complete blood work and instrumental examinations, regular follow-up;
• Patients with age ≥ 2 years;

Exclusion Criteria:

• Patients with osteosarcoma who have received medical treatment (surgery, radiotherapy or chemotherapy) in other hospitals prior to admission to our Institute

pazients with osteosarcoma from 01-01-2000 to 31-12-2020