Team Approach: Osteosarcoma of the Distal Part of the Femur in Adolescents
Osteosarcoma is the most common primary bone cancer in children and adolescents and accounts for approximately 400 to 500 new diagnoses annually, representing up to 10% of new cancer diagnoses in that population in the United States 1,2. Osteosarcoma usually involves the metaphyseal aspect of long bones, with the distal part of the femur, proximal part of the tibia, and proximal part of the humerus being the most common locations. Classic, or conventional, osteosarcoma is the predominant subtype (representing ∼75% of cases) and is a high-grade, intramedullary osteogenic neoplasm of mesenchymal origin that frequently penetrates the bone cortex with an associated soft-tissue mass2-7. Approximately 25% of patients have radiographically detectable metastases at the time of diagnosis. Patients without detectable metastases who are managed with modern cytotoxic chemotherapy and surgical resection have an approximately 70% rate of long-term survival3,8-11, compared with ≤20% for patients who have metastatic disease at the time of diagnosis or those who have local disease progression or metastasis over time2,12,13. The clinical scenario presented in this review is an example of the standard work-up, systemic treatment, surgical resection, and follow-up. The specific surgical reconstruction performed is but one option among many. The specific implant options and outcome data on expandable prostheses are beyond the scope of this review.