[31] Prognostic Value of Subclassification of Pleomorphic Soft Tissue Sarcoma (STS): Myogenic Versus Non-Myogenic Differentiation

Nicole A Cipriani, Pawel Kurzawa, John Mullen, Vikram Deshpande, Rima Ahmad, G Petur Nielsen. Massachusetts General Hospital, Boston, MA; Greater Poland Cancer Centre, Poznan, Poland

Background: Previous studies have demonstrated that patients with pleomorphic soft tissue sarcoma (STS) with myogenic differentiation have a worse prognosis, but these studies include heterogeneous populations of patients who were not uniformly treated. We sought to determine the prognostic significance of myogenic differentiation in a uniformly treated population of adult patients with high-grade pleomorphic STS of the extremities or trunk at a single institution.
Design: 56 patients with large (> 8 cm), grade 2 or 3 extremity or truncal pleomorphic STS received protocol neoadjuvant chemoradiotherapy followed by surgical resection. The tumors were reanalyzed histologically and immunohistochemically and were classified according to strict diagnostic criteria as either non-myogenic or myogenic differentiation if they showed positive staining for at least one muscle marker (muscle actin, smooth muscle actin, desmin). We correlated the line of differentiation with outcome.
Results: Myogenic differentiation was identified in 18 tumors and non-myogenic differentiation was identified in 38 tumors. There were no significant differences between the two groups in tumor size (median 12 cm), grade, or treatment. At a median follow-up of 60 months, the 5-year disease-specific and overall-survival rates in the myogenic and non-myogenic groups were 88% and 88% (p=1.000) and 83% and 79% (p=0.964), respectively.

Conclusions: In a homogeneously treated patients with high-grade extremity and truncal pleomorphic STSwho received neoadjuvant chemoradiotherapy, myogenic differentiation did not predict a worse outcome than non-myogenic differentiation.
Category: Bone & Soft Tissue

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 17, Tuesday Afternoon


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