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Bones & Joints
Osteosarcoma is the most common primary bone cancer in children, adolescents, and young adults (peak age 10-20 years), typically developing in the metaphysis (growing end) of long bones—most commonly around the knee (60-70% of cases: distal femur, proximal tibia) or proximal humerus (upper arm). It presents as progressively worsening bone pain (initially mistaken for growing pains), swelling, and occasionally a palpable mass, often following minor trauma that brings attention to the area. Osteosarcoma is an aggressive malignancy that produces abnormal bone (osteoid) and requires intensive multimodality treatment: neoadjuvant chemotherapy (pre-operative chemotherapy to shrink tumor, 8-12 weeks), limb salvage surgery (removing tumor while preserving limb function with endoprosthesis or allograft reconstruction, 90-95% of cases), and adjuvant chemotherapy (post-operative chemotherapy to kill micrometastases, 6-8 months total). With modern treatment protocols, 5-year survival is 65-70% for localized disease, though metastatic disease at presentation (20% of cases, usually lung) has poorer prognosis (30-40% survival).
What it is and why it happens
Osteosarcoma is the most common primary bone cancer in children, adolescents, and young adults (peak age 10-20 years), typically developing in the metaphysis (growing end) of long bones—most commonly around the knee (60-70% of cases: distal femur, proximal tibia) or proximal humerus (upper arm). It presents as progressively worsening bone pain (initially mistaken for growing pains), swelling, and occasionally a palpable mass, often following minor trauma that brings attention to the area. Osteosarcoma is an aggressive malignancy that produces abnormal bone (osteoid) and requires intensive multimodality treatment: neoadjuvant chemotherapy (pre-operative chemotherapy to shrink tumor, 8-12 weeks), limb salvage surgery (removing tumor while preserving limb function with endoprosthesis or allograft reconstruction, 90-95% of cases), and adjuvant chemotherapy (post-operative chemotherapy to kill micrometastases, 6-8 months total). With modern treatment protocols, 5-year survival is 65-70% for localized disease, though metastatic disease at presentation (20% of cases, usually lung) has poorer prognosis (30-40% survival).