1729P - Resection of high-grade large soft tissue sarcoma with adequate wide margin can lead to good local control without adjuvant radiotherapy

Abstract

BackgroundSoft tissue sarcoma (STS) has been treated by achieving safe surgical margin rather than by using adjuvant radiotherapy (RT) in our country and 2-cm wide margin can be considered as adequate margin according to Kawaguchi’s criteria. We evaluated local recurrence (LR) and prognosis following resection of high-grade large STS using JOA surgical margin concept. MethodsTreatment strategy: Surgical resection with at least 2cm-wide margin was attempted whenever possible. Marginal or 1cm-wide margin are acceptable when preserving neurovascular bundles. RT is conducted postoperatively for marginal or R1 margin. Chemotherapy is indicated for patients less than 60 years old with deep seated, high grade and large tumor. PATIENTS: Inclusion criteria are localized STS in the extremities or trunk, larger than 5cm, FNCLCC grade 2 or 3, limb sparing surgery, primary complete resection at our institution, and minimum 3 years of follow-up. We retrospectively analyzed 69 patients treated between 2007 and 2014. ResultsMedian follow-up was 64 months. Median tumor size was 8.7cm. 6 patients underwent postoperative RT due to inadequate surgical margin. 21 (30%) patients received chemotherapy. There were 7 (10%) LR with average 14.5 months after surgery. Average size of tumor developing LR (14.8cm) was statistically larger than that without LR (9.8cm, p<0.05). Only 1 of 9 patients developed LR after postoperative RT for inadequate resection. Distant metastasis was shown in 14 patients with average 20 months after surgery. There was no statistical difference of LR-free and overall survival between wide resection alone and inadequate resection with postoperative RT. Chemotherapy did not significantly affect overall survival. ConclusionsIn this series of high-grade large STS, resection alone with 2cm-wide margin led to good local control, which is identical to previous reports with surgery plus RT. Adjuvant RT should be given for resection with marginal margin or R1 margin of the resected specimen. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.