MULTIFACTORIAL ANALYSIS OF SURVIVAL IN PRIMARY EXTREMITY LIPOSARCOMA

The treatment of extremity soft tissue sarcoma is now directed at limb preservation with the addition of various adjuvant therapies to improve treatment results. To achieve this goal, a knowledge of prognostic factors for extremity soft tissue sarcoma becomes increasingly critical. The object of this study was to analyze prognostic factors for survival in patients with extremity liposarcoma. Eighty-three patients with primary localized extremity liposarcoma, admitted from 1968 to 1978, were retrospectively reviewed. Surgical resection was the primary mode of treatment. Eleven prognostic factors were analyzed. Tumor factors included: histologic subtype, tumor grade, size, depth, invasion of vital structures, and site; operative factors included: type of operation, and surgical margins; and patient factors included: symptoms, age at diagnosis, and sex. Kaplan-Meier survival curves, and univariate and stratified log-rank tests of association were performed. Independent factors for predicting survival were identified using the Cox model stepwise regression technique. In univariate analysis of the entire group of patients, 5 factors were significant for tumor mortality: tumor grade (p=0.00005), histologie subtype (p=0.00025), tumor size s≥5 cm (p=0.005), type of surgery/ margin (p=0.0001), and invasion of vital structures (p=0.008). When associations among all factors were analyzed, it was found that many factors were interdependent. The independent prognosticators were, therefore, determined according to the Cox model technique. For the multivariate analysis, well-differentiated and lipoblastic liposarcomas were excluded because of lack of survival variation within each group. The former group had no tumor-related deaths and the latter group showed 80% tumor mortality. The remaining patients with myxoid, high-grade fibroblastic and pleomorphic liposarcoma were subjected to multivariate analysis. Three factors emerged as independent prognostic predictors: high-grade tumor (p=0.013), inadequate resection/amputation (p=0.003), and tumor≥cm (p=0.04). © 1990 Société Internationale de Chirurgie.