Development and Validation of a Nomogram for Predicting Recurrence-Free Survival of Surgical Resected Retroperitoneal Liposarcoma

Abstract

Background and Objectives: Surgical treatment is still the mainstay of curative therapy for retroperitoneal liposarcoma (RLPS), but often recurs after surgical resection. We aimed to establish a nomogram for postoperative recurrence of RLPS based on the Asian population. Methods: Patients after surgical resection at the South Hospital of Zhongshan Hospital/ Shanghai Public Health Clinical Center between August 2011 and December 2020 were included. The enrolled patients are randomly divided into training set and test set according to the ratio of 7:3. Prognostic factors were chosen based on Akaike Information Criterion, and the nomogram was built based on Cox regression and then internally validated through calibration plots and concordance index (C-index). Results: A total of 447 patients were included. Gender, age, presentation status, organ invasion and FNCLCC grade were used to build nomogram. The calibration plots showed that RFS predicted probabilities are identical to the actual RFS rates. The C-index of the nomogram was 0.703 (95% CI 0.623-0.783) in the training set and 0.695 (95% CI 0.565-0.825) in test set. Conclusion:The nomogram we established can accurately predict postoperative recurrence of RLPS patients for Asian population.

Development and Validation of a Prognostic Model to Predict the Prognosis of Patients With Retroperitoneal Liposarcoma: A Large International Population-Based Cohort Study

“…Also interesting is the finding that tumor size is an independent risk factor for CSS, not for OS. The 5-cm threshold used in the AJCC staging system is still limited about the value for RPLs because such small RPLs are uncommon in the present and other international studies ( 17 , 25 , 35 , 43 ). Meanwhile, several studies proposed that the optimal threshold in tumor sizes should be revised upward to 10 cm ( 25 , 36 ).…”

“…Additionally, we found that patients with a distant and regional SEER stage had poor OS and CSS than those with a localized SEER stage. As the other authors suggested, patients with tumors invading adjacent structures may be more likely to develop residual microscopic or gross disease after resection ( 17 , 31 , 41 , 44 ). In this study, histological subtype was also an important indicator of prognosis.…”

“…The finding is consistent with previous research showing that increased survival is directly associated with better histologic grade ( 35 , 37 – 40 ). Furthermore, previous analyses showed that completeness of resection is another important prognostic factor ( 17 , 40 – 43 ). We also found that the prognosis of patients who underwent resection was significantly better than that of patients without surgical resection, especially that of patients with radical surgery.…”

“…However, the SEER database lacks these variables and future studies are warranted to further incorporate these variables into analysis. Third, when we included treatment as a prognostic factor, we only considered the effects of surgery and radiotherapy on prognosis, neglecting adjuvant chemotherapy and other medical therapies, such as target therapies, even though most of the research indicates that adjuvant chemotherapy has little to offer for patients with RPLs ( 17 , 48 , 51 , 52 ). Fourth, the SEER provided no information regarding the margin of resection for patients with RPLs.…”

Retroperitoneal Sarcoma Care in 2021

“…In addition to stage, additional known prognostic factors include patient age at presentation, histologic subtype, complete resection with negative margins and without intra-operative tumor rupture, and provision of care at a specialized sarcoma center is associated with better outcomes. Therefore, various staging systems, nomograms and predictive tools have been devised [ 58 , 59 , 60 , 61 ].…”