Prediction of Recurrence-Free and Overall Survival in Retroperitoneal Well-Differentiated and Dedifferentiated Liposarcoma After Surgery

This study was aimed at creating an effective model for predicting the course of the disease in retroperitoneal well-differentiated (WDLPS) and dedifferentiated (DDLPS) liposarcomas after surgery. The study included 111 patients with WDLPS and 74 patients with DDLPS. We developed a methodology for stratification of patients into prognostic groups. Overall survival (OS) and recurrence-free survival (RFS) were analyzed in accordance with it. The highest OS was achieved in the group “favorable prognosis,” while the shortest OS was in the group “extremely poor prognosis” (p < 0.001). The median OS in the “favorable prognosis” group was 225 (95% CI, 174, 276) months; “intermediate prognosis” — 130 (95% CI, 115, 145) months; “poor prognosis” — 90 (95% CI, 79, 101) months; and “extremely poor prognosis” — 22 (95% CI, 15, 29) months. The highest RFS was achieved in the group “favorable prognosis,” while the shortest RFS was achieved in the group “extremely poor prognosis” (p < 0.001). The median RFS in the “favorable prognosis” group was 80 (95% CI, 65, 95) months; “intermediate prognosis” — 47 (95% CI, 33, 61) months; “poor prognosis” — 26 (95% CI, 24, 28) months; “extremely poor prognosis” — 10 (95% CI, 6, 14) months. The method of predicting recurrence-free and overall survival demonstrates an adequate distribution of patients and the reliability of intergroup differences in the survival rate.