Abstract 4524: The independent prognostic nomogram models for primary and recurrent retroperitoneal liposarcoma: A population-based cohort study

Abstract Purpose: The aim of this study was to establish independent prognostic models for primary and recurrent retroperitoneal liposarcoma (RLS). Experimental design: A total of 2429 patients confirmed to have RLS were extracted from the Surveillance, Epidemiology and End Results (SEER) database. The 245 patients collected from the same period at First Medical Center, Chinese People Liberation Army General Hospital (CPLAGH), were used for external validations. Nomogram were built on the basis of clinical practicability, univariate and multivariate Cox analyses. Results: The simplified predictive models for primary RLS was mainly based on tumor size (median size, 162 mm [range, 90-230], P < 0.001) and pathological subtypes (WDL vs DDL, hazard ratio[HR]=2.11; 95% confidence interval [CI]=1.71-2.61; P < 0.001), which can be acquired in the outpatient clinics. However, TNM stage (Stage 1 vs Stage 2, HR=2.18; 95% CI=1.49-3.20; P < 0.001) as an extremely important postoperative indicator was enrolled in the model for recurrent RLS. The area under the time-dependent receiver operating characteristic curve (time-dependent AUC) and concordance index (C-index) of models almost approach 0.75 in the training and validation cohorts. These results indicated favourable discrimination of the models. The calibration curves of the model illustrated good consistency between the predicted and observed survival probabilities in both the training and two validation cohorts. Furthermore, decision curve analysis (DCA) revealed that the nomogram models were clinically useful and had considerable practicability. Conclusion: Efficient and independent models for primary and recurrent RLS will providing clinical guidance for both prognostication and individualized therapeutic decision-making. Citation Format: Huan Deng, Zhenhau Lu, Binrui Wang, Yisheng Pan. v [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4524.