ABSTRACT
Objective. Classic high-grade osteosarcoma is uncommon in preadolescents (less than or equal to 10 years of age). The possibilities of clinicopathologic differences from the typical adolescent osteosarcoma patient have been raised. We sought to compare the presentation, treatment and survival of this subgroup of patients with published rates in order to determine if there is a need to use a treatment regimen different from that for regular adolescent osteosarcoma patients. Methods. Records of the University of the Philippines-Musculoskeletal Tumor Unit (UP-MuST) over a 15-year period (1993-2008) were reviewed and data collected on patients 10 years and younger with biopsy-proven classic high-grade intramedullary osteosarcoma who underwent complete treatment by the Unit. Demographics and survival rates were then compared with published rates for preadolescent and regular adolescent osteosarcoma cases. Results. There were fourteen patients; (6M:8F; age: 4-10 years). The most common presentation was a painful mass in the distal femur (8); the tumors most commonly had osteoblastic histology (12). Treatment consisted of neoadjuvant chemotherapy, wide surgical excision through ablation (9) or limb-saving surgery (5), and postoperative chemotherapy. There was a good histologic response (over 90% tumor necrosis) in four patients. Seven patients are ANED (alive no evidence of disease) 25 to 186 months after diagnosis. Five-year survival estimate is 52%, compared to a dismal 5 to 10% 15 years ago. Conclusion. Clinicopathologic presentation, clinical course, and overall survival in this subgroup of patients are comparable with published results for both preadolescent and adolescent osteosarcoma patients. There is no need to alter the present treatment regimen for this group of young patients.