Neoadjuvant Radiation in High-Grade Soft-Tissue Sarcomas
Melanie Boxberg, Rupert Langer, Klaus Woertler, Carolin Knebel, H. Rechl, Rüdiger von Eisenhart‐Rothe, Wilko Weichert, Stephanie E. Combs, Miriam Hadjamu, Barbara Röper, Katja Specht
Abstract
In this study, we sought to determine the prognostic value of both the European Organization for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group (EORTC-STBSG) score and the histologic parameters viable tumor, coagulative necrosis, hyalinization/fibrosis, and infarction in patients (n=64) with localized, nonmetastatic high-grade soft-tissue sarcomas after preoperative radiomonotherapy. A standardized macroscopic workup for pretreated surgical specimen including evaluation of a whole section of high-grade soft tissue sarcomas in the largest diameter, was used. Association with overall survival and disease-free survival was assessed. Limb salvage could be accomplished in 98.4% of patients. Overall, 90.6% tumors had negative resection margins. The median postoperative tumor diameter was 9 cm. Undifferentiated pleomorphic sarcoma (42.2%) and myxofibrosarcoma (17.2%) were the most common diagnoses. In all, 9.4% of patients had local recurrence despite clear resection margins, and 50% had distant metastases. Morphologic mapping suggests an overall heterogenous intratumoral response to radiotherapy, with significant differences among histologic subtypes. Complete regression (0% vital tumor cells) was not seen. Categorizing the results according to the proposed EORTC-STBSG 5-tier response score, <1% viable tumor cells were seen in 3.1%, ≥1% to <10% viable tumor cells in 20.4%, ≥10% to <50% viable tumor cells in 35.9% and ≥50% viable tumor cells in 40.6% of cases. Mean values for viable tumor cells were 40% (range: 1% to 100%), coagulative necrosis 5% (0% to 60%), hyalinization/fibrosis 25% (0% to 90%) and infarction 15% (0% to 79%). Hyalinization/fibrosis was a significant independent prognostic factor for overall survival (hazard ratio=4.4; P =0.047), while the other histologic parameters including the EORTC-STBSG score were not prognostic.