Undifferentiated pleomorphic sarcoma/NOS (former pleomorphic and storiform MFH) of the extremities is a common malignant soft tissue tumor in adults. The objective of this study is to determine prognostic factors for the outcome after surgical treatment with respect to the recent developments in classification. From 1996 to 2004, 140 undifferentiated pleomorphic sarcomas/NOS were identified out of 1200 soft tissue sarcomas of the extremities that were treated at our institution and recorded in a prospective database. Overall survival (OS) and isolated local recurrence (ILR) were determined by Kaplan-Meier analysis. All tumors were retrospectively analyzed regarding prognostic factors of the disease, including patient’s background (primary or recurrent), histological grade (G2/G3), adjuvant chemotherapy and radiotherapy, size (T1-2) and depth of the tumor, and surgical margins (R0, R1, R2).

In 123 patients, a wide resection was performed (limb sparing surgery). In 9 patients, an amputation was necessary. The overall 5-year survival rate was 72% (median follow-up: 52 months). There was a significant difference between the group presenting with primary tumors (5y survival: 84%, p< 0.05) and recurrent tumors (5y survival: 62%, p< 0.05). Isolated local recurrence occurred in 36 patients.

In terms of OS and ILR, primary or recurrence, negative surgical margins, size and grading had a highly significant influence, whereas the site of surgery and adjuvant chemotherapy, adjuvant radiation and tumor depth did not. Prognosis for patients with undifferentiated pleomorphic sarcoma of the extremities depends predominantly on adequate wide resection of the primary tumor.