Prognostic Factor Analysis and Nomogram Construction of Primary Retroperitoneal Liposarcoma: A Review of 10 Years of Treatment Experience in a Single Asian Cohort of 211 Cases.

Aobo Zhuang,Qian Wu,Weiqi Lu,Yong Zhang,Aojia Zhuang,Hanxing Tong

doi:10.3389/fonc.2021.777647

Abstract

ObjectiveThis study intended to retrospectively analyze the data of patients with primary retroperitoneal liposarcoma in a single Asian large-volume sarcoma center and to establish nomograms focused on PRLPS for predicting progression-free survival (PFS) and overall survival (OS).MethodsA total of 211 patients treated surgically for primary, non-metastatic retroperitoneal liposarcoma during 2009–2021 were identified, and clinicopathologic variables were analyzed. PFS and OS nomograms were built based on variables selected by multivariable analysis. The discriminative and predictive ability of the nomogram was assessed by concordance index and calibration curve.ResultsThe median follow-up time was 25 months. A total of 117 (56%) were well-differentiated, 78 (37%) were dedifferentiated, 13 (6%) were myxoid, and 3 (1%) were pleomorphic morphology. Compared to the western population cohort reported by the Memorial Sloan-Kettering Cancer Center, the median age of patients in this cohort was younger (57 vs. 63 years), the tumor burden was lower (20 vs. 26 cm), and the proportion of patients with R0 or R1 resection was higher (97% vs. 81%). The 5-year PFS rate was 49%, and factors independently associated with PFS were symptoms at visit, preoperative needle biopsy, histologic subtypes, and postoperative hospital stay. The 5-year OS rate was 72%. American Society of Anesthesiologists Physical Status and Clavien-Dindo classification were independently associated with OS. The concordance indexes for PFS and OS nomograms were 0.702 and 0.757, respectively. The calibration plots were excellent.ConclusionsThe proposed nomogram provided a favorable reference for the treatment of primary retroperitoneal liposarcoma patients.

Highlights

Retroperitoneal soft tissue sarcomas (RPS), excluding visceral sarcomas, accounted for 0.15% of all malignancies and approximately 15% of soft tissue sarcomas [1]
Compared to the western population cohort reported by the Memorial Sloan-Kettering Cancer Center, the median age of patients in this cohort was younger (57 vs. 63 years), the tumor burden was lower (20 vs. 26 cm), and the proportion of patients with R0 or R1 resection was higher (97% vs. 81%)
The 5-year progression-free survival (PFS) rate was 49%, and factors independently associated with PFS were symptoms at visit, preoperative needle biopsy, histologic subtypes, and postoperative hospital stay

Summary

Introduction

Retroperitoneal soft tissue sarcomas (RPS), excluding visceral sarcomas, accounted for 0.15% of all malignancies and approximately 15% of soft tissue sarcomas [1]. The recurrence rate of RPS for 5 years after resection is more than 50% [3, 4]. Retroperitoneal liposarcoma is the most common pathological subtype of RPS, accounting for a half of them [5]. Previous studies based on large samples of Western populations have shown that histologic subtype and contiguous organ resection are independent risk factors for postoperative recurrence of primary retroperitoneal liposarcoma [6] (PRLPS). Previous studies have reported that there may be differences in biological behavior and treatment strategies between eastern and western populations of RLPS [7], but there are very few reports based on Asian populations, and the sample size is small [8, 9]

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Conclusion