BMC Cancer Research article BioMed Central Open Access Liposarcoma: exploration of clinical prognostic factors for risk based stratification of therapy Hyo Song Kim1,6, Jeeyun Lee*1, Seong Yoon Yi1, Hyun Jung Jun1, Yoon- La Choi2, Geung Hwan Ahn2, Sung Wook Seo3, Do Hoon Lim4, Yong Chan Ahn4, Joon Oh Park1 and Sung Joo Kim*5 Address: 1Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, 2Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, 3Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, 4Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, 5Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea and 6Division of Medical Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea Email: Hyo Song Kim - bbosong77@gmail.com; Jeeyun Lee* - jyunlee@skku.edu; Seong Yoon Yi - sy93.yi@samsung.com; Hyun Jung Jun - hj77.jun@samsung.com; Yoon-La Choi - yla.choi@samsung.com; Geung Hwan Ahn - g.ahn@samsung.com; Sung Wook Seo - sungwook.seo@samsung.com; Do Hoon Lim - dh8.lim@samsung.com; Yong Chan Ahn - ycahn.ahn@samsung.com; Joon Oh Park - joonoh.park@samsung.com; Sung Joo Kim* - kmhyj.kim@samsung.com * Corresponding authors Published: 26 June 2009 BMC Cancer 2009, 9:205 doi:10.1186/1471-2407-9-205 This article is available from: http://www.biomedcentral.com/1471-2407/9/205 Received: 11 November 2008 Accepted: 26 June 2009 © 2009 Kim et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract factors. Background: Prognosis and optimal treatment strategies of liposarcoma have not been fully defined. The purpose of this study is to define the distinctive clinical features of liposarcomas by assessing prognostic Methods: Between January 1995 and May 2008, 94 liposarcoma patients who underwent surgical resection with curative intent were reviewed. Results: Fifty patients (53.2%) presented with well differentiated, 22 (23.4%) myxoid, 15 (16.0%) dedifferentiated, 5 (5.3%) round cell, and 2 (2.1%) pleomorphic histology. With the median 14 cm sized of tumor burden, about half of the cases were located in the retroperitoneum (46.8%). Seventy two (76.6%) patients remained alive with 78.1%, and 67.5% of the 5- and 10-year overall survival (OS) rates, respectively. Low grade liposarcoma (well differentiated and myxoid) had a significantly prolonged OS and disease free survival (DFS) with adjuvant radiotherapy when compared with those without adjuvant radiotherapy (5-year OS, 100% vs 66.3%, P = 0.03; 1-year DFS, 92.9% vs 50.0%, respectively, P = 0.04). Independent prognostic factors for OS were histologic variant (P = 0.001; HR, 5.1; 95% CI, 2.0 – 12.9), and margin status (P = 0.005; HR, 4.1; 95% CI, 1.6–10.5). We identified three different risk groups: group 1 (n = 66), no adverse factors; group 2, one or two adverse factors (n = 28). The 5-year OS rate for group 1, and 2 were 91.9%, 45.5%, respectively. Conclusion: The histologic subtype, and margin status were independently associated with OS, and adjuvant radiotherapy seems to confer survival benefit in low grade tumors. Our prognostic model for primary liposarcoma demonstrated distinct three groups of patients with good prognostic discrimination. Page 1 of 8 (page number not for citation purposes)