title: Liposarcoma: exploration of clinical prognostic factors for risk based stratification of therapy.
abstract: 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 factors.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors: Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. bbosong77@gmail.com
authors: Hyo Song
authors: HS
authors: Kim
authors: Jeeyun
authors: J
authors: Lee
authors: Seong Yoon
authors: SY
authors: Yi
authors: Hyun Jung
authors: HJ
authors: Jun
authors: Yoon-La
authors: YL
authors: Choi
authors: Geung Hwan
authors: GH
authors: Ahn
authors: Sung Wook
authors: SW
authors: Seo
authors: Do Hoon
authors: DH
authors: Lim
authors: Yong Chan
authors: YC
authors: Ahn
authors: Joon Oh
authors: JO
authors: Park
authors: Sung Joo
authors: SJ
authors: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008080:Liposarcoma / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D008297:Male; D008495:Medical Oncology / Q000379:methods; D008875:Middle Aged; D011379:Prognosis; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012306:Risk; D012307:Risk Factors; D016896:Treatment Outcome