Impact of Postoperative Radiation on Survival for High-grade Soft Tissue Sarcoma of the Extremities After Limb Sparing Radical Resection

Abstract

To use the Surveillance, Epidemiology, and End Results (SEER) Database to analyze the impact of postoperative radiation after limb sparing surgery for high-grade extremity soft tissue sarcomas (STS). We identified patients, aged 20 to 79, who were diagnosed between 1988 and 2006 with high-grade STS of the extremities and underwent radical limb sparing surgery with or without postoperative external beam radiation. Kaplan-Meier and Cox regression analyses were performed to evaluate the effect of postoperative external beam radiation therapy on overall survival (OS) and disease-specific survival (DSS). A total of 983 patients met the selection criteria: 788 (80.2%) received postoperative radiation and 195 (19.8%) underwent surgery alone. For the whole cohort, there were no differences between the groups in OS (P=0.06) or DSS (P=0.20). On subgroup analysis, for tumors ≤5 cm there remained no significant differences in OS (P=0.8) or DSS (P=0.93). However, for tumors >5 cm the 3-year OS improved with the addition of postoperative radiation from 55.6% to 73.4% (P<0.001). Similarly, the 3-year DSS improved from 68.1% to 80.6% (P=0.005). Because of the retrospective nature of this study and inherent limitations of the SEER database, a large prospective study is needed to further elucidate the relationship between postoperative radiation and survival. However, these data do support the use of adjuvant radiation for patients with high-grade extremity STS measuring >5 cm.