Malignant Sarcoma of the Pelvic Bones Treatment Outcomes and Prognostic Factors Vary by Histopathology

BACKGROUND: Treatment of malignant sarcomas of the pelvis poses a challenge for local disease control and oncologic outcome. Many reports have described the dismal outcomes. Most studies are retrospective series coming out of single centers, thus biased toward patient selection and are of limited statistical power. METHODS: The authors used the Surveillance, Epidemiology, and End Results database to analyze 1185 pelvic sarcoma cases from 1987 to 2006. Kaplan-Meier and Cox regression were used to analyze the significance of prognostic factors. The analysis was repeated for different histopathological subtypes to determine specific prognostic factors in each case. RESULTS: Incidence of pelvic sarcoma in 2006 was 89 per 100,000 persons; it has significantly increased since 1973 (P < .05). The overall 5-year survival for all the patients with pelvic sarcoma was 47%, with osteosarcoma having the worst 5-year survival at 19% and patients with chordoma having the best 5-year survival at 60%. Independent prognostic factors included age, stage, grade, size of primary lesion, histopathology, and treatment-related factors. Comparing the patients only with high-grade lesions, patients with Ewing sarcoma have the best prognosis. CONCLUSIONS: This is an analysis of patients with pelvic sarcomas derived from a population-based registry. Survival and prognostics vary with histopathological diagnoses. Although surgical resection was associated with superior outcomes for osteosarcoma and chondrosarcoma, there was no significant difference in outcomes of patients with Ewing sarcoma treated with surgery and/or radiotherapy. Cancer 2011; 117: 1529-41. (C) 2010 American Cancer Society.