Prognostic relevance of the TNM classification 8th edition and new criteria of staging for retroperitoneal liposarcoma

For the first time a section appeared for staging of non-organ retroperitoneal tumors in the UICC TNM classification 8th edition. Aim.To assess the prognostic significance of the TNM classification eighth edition for the most common retroperitoneal tumors-liposarcoma. Materials and methods.The distribution of patients by stages and survival in accordance with the TNM-8 classification were studied in192 patients with retroperitoneal non-organ liposarcoma (RLPS). Results.In the TNM-8 classification, only the degree of malignancy of the tumor has a prognostic value, and the T-category does not reflect the actual size of the RLPS and is considered T4 in 93%, which leads to inadequate staging. During the 15-year period, there were no cases with stages II and IIIA, and the survival rate was estimated only in patients with stages I and IIIB. A TNM classification with new values of the T-category was proposed, which demonstrated a more adequate distribution of patients by stages and the reliability ofintergroup differences in the survival rate. Conclusion.It is advisable to create a special TNM classification for RLPS, which makes up more than half of all retroperitoneal sarcomas.