Liposarcoma: exploration of clinical prognostic factors for risk based stratification of therapy.
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.
Kim
Hyo Song
HS
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. bbosong77@gmail.com
Lee
Jeeyun
J
Yi
Seong Yoon
SY
Jun
Hyun Jung
HJ
Choi
Yoon-La
YL
Ahn
Geung Hwan
GH
Seo
Sung Wook
SW
Lim
Do Hoon
DH
Ahn
Yong Chan
YC
Park
Joon Oh
JO
Kim
Sung Joo
SJ
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