Backgrounds and Objectives
This investigation described clinicopathological features and outcomes of extraskeletal myxoid chondrosarcoma (EMC) patients.
Methods
EMC patients were identified from the United States Sarcoma Collaborative database between 2000 and 2016. Overall survival (OS) and recurrence‐free survival (RFS) were calculated, and prognostic factors were analyzed.
Results
Sixty individuals with a mean age of 55 years were included, and 65.0% (n = 39) were male. 73.3% (n = 44) had a primary tumor. A total of 41.6% (n = 25) developed tumor relapse following resection. The locoregional recurrence rate was 30.0% (n = 18/60), and mean follow‐up was 42.7 months. The 5‐year OS was 71.0%, while the 5‐year RFS was 41.4%. On multivariate analysis for all EMC, chemotherapy (hazard ratio [HR], 6.054; 95% confidence interval [CI], 1.33−27.7; p = 0.020) and radiation (HR, 5.07, 95% CI, 1.3−20.1; p = 0.021) were independently predictive of a worse RFS. Among patients with primary EMC only, the 5‐year OS was 85.3%, with a 30.0% (n = 12) locoregional recurrence rate, though no significant prognostic factors were identified.
Conclusions
Long‐term survival with EMC is probable, however there exists a high incidence of locoregional recurrence. While chemotherapy and radiation were associated with a worse RFS, these findings were likely confounded by recurrent disease as significance was lost in the primary EMC‐only subset.