Long-term Outcomes for Extraskeletal Myxoid Chondrosarcoma: A SEER Database Analysis.

Area of Science:

• Oncology
• Surgical Oncology
• Medical Oncology

Background:

• Extraskeletal myxoid chondrosarcoma (EMCS) is a rare tumor with a typically indolent course but a high recurrence rate.
• Understanding factors influencing metastasis, treatment, and survival is crucial for managing this rare cancer.

Purpose of the Study:

• To assess factors associated with metastasis, treatment, and survival in patients with extraskeletal myxoid chondrosarcoma (EMCS).
• To establish overall survival (OS) benchmarks and provide guidance for future clinical trial stratification.

Main Methods:

• Utilized the Surveillance, Epidemiology, and End Results (SEER) database (1973-2016) for patients diagnosed with myxoid chondrosarcoma.
• Employed Kaplan-Meier analyses and Cox proportional hazard models to evaluate survival predictors, and logistic regression for tumor location and distant disease associations.
• Conducted primary complete case analysis and a sensitivity analysis using multiple imputation (MI).

Main Results:

• Locoregional disease (LRD) was present in 85% of patients.
• Univariate analysis indicated surgery correlated with superior OS, while chemotherapy and radiotherapy were associated with inferior OS.
• Adjusted sensitivity analysis revealed surgery was linked to superior outcomes, with no OS difference based on primary tumor site. The 10-year OS for distant disease was 10%.

Conclusions:

• Surgery for locoregional disease (LRD) in EMCS is associated with improved overall survival (OS), supported by univariate and adjusted analyses.
• No significant OS benefit was observed with the use of chemotherapy or radiotherapy.
• This study provides the largest report on EMCS with long-term follow-up, highlighting poor outcomes with metastatic disease and offering benchmarks for future research.