Histopathological re-classification of extremity pleomorphic soft tissue sarcoma has clinical relevance

The aims were to describe the clinico-pathological features of 65 patients affected by soft tissue pleomorphic sarcomas of the extremities, to evaluate their clinical outcome and to explore the prognostic impact of clinical and pathologic parameters, on disease-free and overall survival.

Soft tissue pleomorphic sarcomas of the extremities were retrieved to be retrospectively re-evaluated in the current analysis. The following parameters were analysed: age, sex, site, size, stage, histotype, grade, surgical margins, therapy. Disease-free and overall survival rates were calculated according to the Kaplan-Meier method. A multivariate analysis was used to determine which variable had an independent effect on clinical outcome.

Sixty-five patients with soft tissue pleomorphic sarcomas of the extremities were included in the study. Upon revision, there were 22 leiomyosarcomas, 13 myxofibrosarcomas, 9 liposarcomas, 10 pleomorphic MFH/undifferentiated high grade pleomorphic sarcomas, and 11 cases were other types of plemorphic sarcomas, including rhabdomyosarcoma (n=4), osteosarcoma (n=2), myofibrosarcoma (n=5). In the whole series, by multivariate analysis, stage was the only factor predictor of disease progression (p=0.001; RR 6.9; 95% CI 1.3-15.6). Considering only localized pleomorphic sarcomas the independent predictors of disease relapse were site (p=0.03; RR 3.6; 95% CI 1.0-12.4) and myogenic differentiation (p=0.04; RR 2.9; 95% CI 0.9-10.0), whereas myogenic differentiation resulted the only independent predictor of overall survival (p=0.03; RR 6.5; 95% CI 1.1-37.9).

These results indicate that histopathological classification of soft tissue pleomorphic sarcomas is clinically relevant. In our experience, AJCC stage and myogenic differentiation are the factors which independently affect prognosis.