[90] Prognostic Factors in a Single-Centre Series of 160 Cases of Myxoid/Round Cell Liposarcomas (MRLS)

VP Sumathi, RJ Grimer, D Peake, L-G Kindblom. The Royal Orthopaedic Hospital NHS Foundation Trust, Birmingham, United Kingdom

Background: MRLS is the second most common subtype of liposarcoma and exhibits a wide spectrum of clinical behaviour. The extent of round cell component is known to influence the outcome, but the cut-of percentage has been widely debated. This study aimed to identify clinical and morphologic prognosticators.
Design: A long term follow-up data from 160 patients with primary MRLS, surgically treated at our centre were statically analysed for prognostic factors.Histology was reviewed in 130(81%) cases.
Results: The tumours occured in patients with a median age of 48, had a median size of 11cm and predominantly involved the lower extremities (148/160). 53% (69/130)of the tumours had a round cell component (equal or <5% in 40%, >5% in 60%). Local recurrence occured in 12%(19/160), metastatic disease in 33% (52/160) and disease specific 5 and 10 year survivals were 75% and 56% respectively( median follow-up for surviving patients was 6.7 years). In 38/52(73%) patients with metastatic disease, the metastases only involved extrapulmonary sites,particularly the soft tissues. 15 patients who received postoperative radiotherapy for contaminated margins did not develop local recurrence.
Conclusions: Multivariate statistical analysis showed that any round cell component( even 1-5%) in MRLS, age > 50 years and tumour size of > 10cms are associated with increased risk of local recurrence and poorer disease specific survival.Post operative radiotherapy for narrow or intralesional margins decreases the risk of local recurrence.
Category: Bone & Soft Tissue

Monday, March 9, 2009 1:00 PM

Poster Session II # 5, Monday Afternoon