1501P - Liposarcoma (LPS): influence of primary tumor site and histological sub-type on clinical outcomes

Date 29 September 2012
Event ESMO Congress 2012
Session Poster presentation I
Topics Soft Tissue Sarcomas
Pathology/Molecular Biology
Presenter Si Lin Koo
Authors S.L. Koo1, A. Sairi1, S. Pan2, L. Foo Siang Sheng3, T. Mann Hong3, F. Chin4, K. Sittampalam5, M. Teo6, M. Farid1, R. Quek1
  • 1Medical Oncology, National Cancer Centre Singapore, 169610 - Singapore/SG
  • 2Division Of Clinical Trials And Biostatisics, National Cancer Centre Singapore, 169610 - Singapore/SG
  • 3Orthopaedic Surgery, Singapore General Hospital, 169610 - Singapore/SG
  • 4Radiation Oncology, National Cancer Centre Singapore, 169610 - Singapore/SG
  • 5Pathology, Singapore General Hospital, 169610 - Singapore/SG
  • 6Surgical Oncology, National Cancer Centre Singapore, 169610 - Singapore/SG

Abstract

Background

Liposarcoma is a heterogeneous group disease composed of molecularly distinct subsets. Detailed information on LPS as a narrowly-defined sarcoma entity is lacking. In this study we sought to evaluate prognostic factors of LPS, in particular, study the influence of primary tumor site and histological sub-types on clinical outcomes.

Methods

Single center retrospective study of 101 consecutive LPS patients (pts) from 2002 to 2012 were identified from our institutional sarcoma database and analyzed.

Results

Median age of pts was 55 yrs; 97% presented with localized disease of whom 45% originated from the extremities. Histological sub-classification as follows: 40% well-differentiated, 39% well-differentiated/ de-differentiated, 18% myxoid and 4% pleomorphic LPS. Of 98 pts with localized disease, 99% underwent wide excision. In those with available surgical data, R0/R1 resection margins were achieved in 49% and 50% respectively. Forty-three percent and 6% received adjuvant radiation (RT) and chemotherapy respectively. At a median follow-up of 47 mths, median relapse-free survival (RFS) for R0/R1 resected pts was 49 mths (2yr RFS 68%). In the univariate analysis, primary tumor site originating in the extremities (p = 0.019) and use of adjuvant radiation (p = 0.008) were significantly associated with improved RFS. Notably, pts with axial LPS had significantly higher rates of relapse, 58% vs 37%, (p = 0.043) with a significantly higher proportion being local-only relapses, 77% vs 44% (p = 0.028) compared with extremity LPS. Median overall survival (OS) of pts with localized LPS was 113 mths. For pts with metastatic disease, median OS was 21 mths. In univariate analysis, use of palliative chemotherapy (p = 0.046) was significantly correlated with superior OS. LPS sub-type did not significantly influence RFS or OS.

Conclusions

Our study demonstrates that primary tumor site and use of adjuvant RT but not LPS sub-type are important prognostic factors for RFS in pts with localised LPS. This knowledge may potentially guide local treatment decisions including the use of more aggressive surgery, adjuvant radiation and even chemotherapy in selected patients.

Disclosure

All authors have declared no conflicts of interest.