A novel nomogram for predicting local recurrence-free survival after surgical resection for retroperitoneal liposarcoma from a Chinese tertiary cancer center

Background Local recurrence is the most difficult postoperative challenge and the leading cause of death in patients with retroperitoneal liposarcoma (RLPS). We aimed to establish a postoperative nomogram exclusively focused on RLPS for predicting local recurrence-free survival (LRFS). Methods A cohort of 124 patients after surgical resection with curative intent in the Peking University Cancer Hospital Sarcoma Center were included in the study. Demographic, clinicopathologic, and treatment variables were analyzed using the Cox regression model. Significant clinically relevant variables in multivariable analysis were incorporated into the RLPS-specific nomogram. The discriminative ability and predictive accuracy of the nomogram were assessed by calculating the concordance index and drawing a calibration plot. Results At a median follow-up of 26.5 (interquartile range 10.9-39.4) months, 71 patients had recurrent disease. The 3-year and 5-year LRFS rates were 35.6% (95% confidence interval, 27.0-46.9%) and 28.2% (95% CI 15.8-38.6%), respectively. Multivariate analysis identified the French Federation of Cancer Centers Sarcoma Group (FNCLCC) grade and completeness of resection as independent predictors of LRFS. Variables included in our nomogram were: presentation status, multifocality, completeness of resection, histologic subtypes, and FNCLCC grade. The concordance index of our nomogram was 0.732 (95% CI 0.667-0.797) and the calibration plot was excellent. Conclusions Our novel nomogram for patients with resected RLPS could improve recurrence risk stratification to explore molecular analysis associated with recurrence.