Natural history of undifferentiated pleomorphic sarcoma: Experience from the US Sarcoma Collaborative.

BACKGROUND: Undifferentiated pleomorphic sarcoma (UPS) is a relatively rare but aggressive neoplasm. We sought to utilize a multi-institutional US cohort of sarcoma patients to examine predictors of survival and recurrence patterns after resection of UPS. METHODS: From 2000 to 2016, patients with primary UPS undergoing curative-intent surgical resection at seven academic institutions were retrospectively reviewed. Epidemiologic and clinicopathologic factors were reviewed by site of origin. Overall survival (OS), recurrence-free survival (RFS), time-to-locoregional (TTLR), time-to-distant recurrence (TTDR), and patterns of recurrence were analyzed. RESULTS: Of the 534 UPS patients identified, 53% were female, with a median age of 60 and median tumor size of 8.5 cm. The median OS, RFS, TTLR, and TTDR for the entire cohort were 109, 49, 86, and 46 months, respectively. There were no differences in these survival outcomes between extremity and truncal UPS. Compared with truncal, extremity UPS were more commonly amenable to R0 resection (87% vs. 75%, p = 0.017) and less commonly associated with lymph node metastasis (1% vs. 6%, p = 0.031). R0 resection and radiation treatment, but not site of origin (extremity vs. trunk) were independent predictors of OS and RFS. TTLR recurrence was shorter for UPS resected with a positive margin and for tumors not treated with radiation. CONCLUSION: For patients with resected extremity and truncal UPS, tumor size >5 cm and positive resection margin are associated with worse survival OS and RFS, irrespectively the site of origin. R0 surgical resection and radiation treatment may help improve these survival outcomes.

Extraskeletal myxoid chondrosarcoma: Clinicopathological features and outcomes from the United States sarcoma collaborative database.

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.