Effect of adjuvant radiotherapy on survival in localized limb or trunk wall well-differentiated liposarcoma (WDLPS).

Abstract

10079 Background: WDLPS accounts for about 10% of all soft tissue sarcoma and may arise in any part of the body. Whether post operative radiotherapy is useful in the management of these patients after definitive surgery remains unclear. Methods: Searching the online virtual Conticanet tumor bank conticabase, 195 patients with parietal trunk or extremities WDLPS with pathological central review within the French Sarcoma Group pathologist working party were identified. Dedifferentiated, myxoid/round cell and pleomorphic LPS were excluded. Patient had had primary surgery between 1980 and 2008 in 17 French and Swiss medical centers. Prognostic factors for RFS and OS were investigated in univariate and multivariate analysis, including the use of adjuvant external bean radiotherapy (EBR) mostly given in 2gy fractions over 50-60. Results: 96 males and 99 females, with a median age of 60 were identified. Primary sites were lower limb (156, 80%), trunk wall (15, 8%), groin / shoulder girdles (14, 7%), upper limb (10, 5%). Median size of the primary was 17cm (range 3-40). 163 (84%) pts were followed since the first event, 32 (16%) had had prior surgery on the same tumor. 78 (40%), 76 (39%), 4 (2%) had R0, R1, and R2 resection as first treatment respectively, 103 (53%) patients received postoperative radiotherapy (EBR). 163 patients had a primary surgery in a sarcoma center, and 32 had primary surgery in a primary care center. With a median follow-up of 87 months there were 14 deaths, 15 local relapses, no metastatic relapse.Only EBR and proximal/trunk sites were found significantly associated with RFS in univariate analyses, for both the whole series, and the series of patients treated in reference centers. EBR was the only independent parameter for RFS in multivariate analysis. In the group of 163 patients operated upfront in sarcoma centers, gender, age, trunk/proximal sites, R2 resection, EBR, were retained as independent prognostic factors for overall survival in multivariate analysis, along with, primary surgery in a sarcoma center in the whole series. Conclusions: In this series of 195 WDLPS, relapses occurred only locally and post operative radiotherapy was associated with an improved RFS and overall survival. No significant financial relationships to disclose.