Extraskeletal osteosarcoma: A large series treated at a single institution

Area of Science:

• Oncology
• Pathology
• Surgical Oncology

Background:

• Extraskeletal osteosarcoma (ESOS) is an exceptionally rare malignant tumor.
• Understanding its prognostic factors and optimal treatment is crucial for patient outcomes.

Purpose of the Study:

• To present a large cohort of extraskeletal osteosarcoma (ESOS) cases.
• To evaluate prognostic factors and treatment strategies for ESOS.

Main Methods:

• Retrospective review of medical records for 41 patients diagnosed with ESOS between 1960 and 2016.
• Kaplan-Meier analysis and Cox proportional hazards regression were employed to identify survival-affecting variables.

Main Results:

• Surgery and type of surgery significantly impacted overall survival (OS) (p<0.001).
• Chemotherapy and radiation therapy (RT) did not significantly affect OS, local recurrence, or progression-free survival overall.
• RT improved OS in patients with incomplete resection (p=0.03).
• ESOS survival curves more closely resemble non-rhabdomyosarcoma soft tissue sarcomas (NRSTS).

Conclusions:

• Wide surgical resection is the preferred treatment for ESOS.
• For patients undergoing incomplete resection, RT may enhance overall survival.
• ESOS exhibits clinical behavior more aligned with NRSTS than with bone osteosarcoma.