Review Question - QID 215768

The radiographs, MRI, and biopsy specimens are consistent with osteosarcoma. The correct treatment protocol is neoadjuvant chemotherapy for about 10 weeks, followed by wide resection, and finished off with adjuvant chemotherapy for roughly 26-28 weeks. The preferred protocol in the United States is MAP (high dose methotrexate, adriamycin (aka doxorubicin), and cisplatin).

Osteosarcoma is the most common primary bone sarcoma and has a bimodal distribution. The first peak is in the second decade of life, and the second peak is usually seen in patients aged in their 60s. It primarily affects the highly active metaphyseal portions of growing bones like the distal femur, proximal tibia, and proximal humerus. The standard workup includes radiographs and MRI with and without contrast of the entire bone, chest CT scan, and whole-body bone scan. About 1 in 5 patients present with pulmonary metastases.

The European and American Osteosarcoma Study Group (EURAMOS)-1 trial demonstrated no significant benefit was gained from the addition of other cytotoxic agents (ifosfamide and etoposide, also known as the MAPIE protocol) for patients with poor response to neoadjuvant MAP chemotherapy.

Yu et al. completed a meta-analysis of seven studies including 3,433 patients to evaluate 3-year and 5-year event-free survival (EFS) and 3-year and 5-year overall survival (OS) in patients given MAP versus MAP + other chemotherapy agents. They found no statistically significant difference in 3EFS, 3OS, 5EFS, 5OS, and mortality rates among osteosarcoma patients when MAP was compared with MAP+ regimen. MAP regimen showed statistically lower incidence rates of chemotherapy toxicities.

Figures A and B are the AP and lateral radiographs showing a mixed osteolytic and osteoblastic lesion of the distal femoral metaphysis with ill-defined borders, periosteal reaction, and soft tissue expansion. Figures C and D are coronal and sagittal T1 fat-saturated post-contrast MRIs of the left distal femur showing a heterogeneous, aggressive appearing bone lesion with soft tissue expansion. Figures E and F are the low-power and high-power histology slides showing pleomorphic cells and lacy osteoid, consistent with osteosarcoma.

Incorrect Answers:
Answers 1, 3, 4, 5 are incorrect as multiple RCTs and meta-analyses have demonstrated high dose methotrexate, adriamycin (aka doxorubicin), and cisplatin to be the preferred systemic chemotherapy regimen in patients with osteosarcoma. The addition of etoposide, ifosfamide, and other chemotherapy agents has not improved event-free and overall survival.