Undifferentiated Pleomorphic Sarcoma: Long-Term Follow-Up from a Large Institution

PURPOSE: Our study aimed to describe the clinical features of undifferentiated pleomorphic sarcoma (UPS) and identify the predictors of poor outcomes. PATIENTS AND METHODS: The clinicopathological variables and treatment strategies of 100 UPS patients who underwent surgical resections at a single institution between November 2004 and July 2016 were reviewed. Kaplan–Meier and Cox regression method were conducted for survival analysis. RESULTS: The median follow-up time was 94 months (range, 1.5–154 months). R0 resection was applied for 72 cases, and the median tumor size was 5.75cm (range, 1–30cm). Tumor grades of 45 patients were intermediate grade (G2), and 54 patients were with advanced stage (stage III/IV). Twenty-seven patients presented with tumors involving important structures, in which the nerve was the most frequently invaded structure (n=12). During the follow-up, 40 patients suffered from postoperative local recurrence, and distant metastasis was observed in 25 patients which mainly metastasized to the lung (n=14). The 5-year OS rate, 5-year LRFS rate, and 5-year MFS rate was 53%, 55%, and 70%, respectively. Multivariate analysis revealed that tumor presentation, tumor size, and important structures involved (p=0.033, p=0.004, and p=0.033, respectively) were independent prognostic factors associated with OS. Meanwhile, age, resection quality and tumor grade were independent prognostic factors for LRFS (p=0.033, p=0.045, and p=0.007, respectively) and tumor depth was significantly associated with MFS (p=0.050) in multivariate analysis. CONCLUSION: Primary treatment of UPS should be conducted by experts in large sarcoma center. Wide surgical margin provides sufficient control of the disease recurrence.