Objective: This 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). Methods: A 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. Results: The 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. Conclusions: The proposed nomogram provided a favorable reference for the treatment of primary retroperitoneal liposarcoma patients.

Background: Treating patients with advanced sarcomas is challenging due to great histologic diversity among its subtypes. Leiomyosarcoma (LMS) and de-differentiated liposarcoma (DDLPS) are two common and aggressive subtypes of soft tissue sarcoma (STS). They differ significantly in histology and clinical behaviors. However, the molecular driving force behind the difference is unclear.Methods: We collected 20 LMS and 12 DDLPS samples and performed whole exome sequencing (WES) to obtain their somatic mutation profiles. We also performed RNA-Seq to analyze the transcriptomes of 8 each of the LMS and DDLPS samples and obtained information about differential gene expression, pathway enrichment, immune cell infiltration in tumor microenvironment, and chromosomal rearrangement including gene fusions. Selected gene fusion events from the RNA-seq prediction were checked by RT-PCR in tandem with Sanger sequencing.Results: We detected loss of function mutation and deletion of tumor suppressors mostly in LMS, and oncogene amplification mostly in DDLPS. A focal amplification affecting chromosome 12q13–15 region which encodesMDM2,CDK4andHMGA2is notable in DDLPS. Mutations inTP53,ATRX,PTEN, andRB1are identified in LMS but not DDLPS, while mutation of HERC2 is only identified in DDLPS but not LMS. RNA-seq revealed overexpression ofMDM2,CDK4andHMGA2in DDLPS and down-regulation ofTP53andRB1in LMS. It also detected more fusion events in DDLPS than LMS (4.5 vs. 1,p = 0.0195), and the ones involving chromosome 12 in DDLPS stand out. RT-PCR and Sanger sequencing verified the majority of the fusion events in DDLPS but only one event in LMS selected to be tested. The tumor microenvironmental signatures are highly correlated with histologic types. DDLPS has more endothelial cells and fibroblasts content than LMS.Conclusions: Our analysis revealed different recurrent genetic variations in LMS and DDLPS including simultaneous upregulation of gene expression and gene copy number amplification ofMDM2andCDK4. Up-regulation of tumor related genes is favored in DDLPS, while loss of suppressor function is favored in LMS. DDLPS harbors more frequent fusion events which can generate neoepitopes and potentially targeted by personalized immune treatment.

Objective: This investigation aimed to explore the relationship between sarcopenia and severe postoperative complications, relapse-free survival (RFS), and overall survival (OS) in patients with retroperitoneal liposarcoma (RLPS). Material and methods: This retrospective study included 72 RLPS patients (47 men, 25 women; mean age, 57.49 years, SD 10.92) who had abdominal CT exams. Clinical information was recorded, including RLPS characteristics (histologic subtypes, grade, size), laboratory assessment (ALB, PALB, A/G, Hb, SCr), relapse-free survival, overall survival, and postoperative complications. The relationships between those variables and RFS and OS were analyzed using Cox proportional hazard models. Results: There were 8 severe postoperative complications (Clavien-Dindo grade > 2). The chi-square test showed sarcopenia was associated with severe postoperative complications (P = 0.011). In multivariate analysis, sarcopenia was not associated with relapse-free survival (P = 0.574) and overall survival (P = 0.578). Conclusions: Sarcopenia predicts worse surgical complications but does not affect relapse-free survival and overall survival.

Background: Surgery is the cornerstone of the treatment for primary retroperitoneal sarcoma (RPS). The purpose of this study was to establish a nomogram predictive model for predicting postoperative morbidity in primary RPS.Methods: Clinicopathological data of patients who underwent radical resection from 2009 to 2021 were retrospectively analyzed. Risk factor analysis was performed using a logistic regression model, and modeling variables were selected based on Akaike Information Criterion. The nomogram prediction model was built on the basis of a binary logistic regression model and internally validated by calibration curves and concordance index.Results: A total of 319 patients were enrolled, including 162 males (50.8%). 22.9% (n = 73) were over 65 years of age, and 70.2% (n = 224) had tumors larger than 10 cm. The most common histologic subtypes were well-differentiated liposarcoma (38.2%), dedifferentiated liposarcoma (25.1%) and leiomyosarcoma (7.8%). According to the Clavien–Dindo Classification, 96 (31.1%) and 31 (11.6%) patients had grade I–II complications and grade III–V complications, respectively. Age, tumor burden, location, operative time, number of combined organ resections, weighted resected organ score, estimated blood loss and packed RBC transfusion was used to construct the nomogram, and the concordance index of which was 0.795 (95% CI 0.746–0.844). and the calibration curve indicated a high agreement between predicted and actual rates.Conclusions: Nomogram, a visual predictive tool that integrates multiple clinicopathological factors, can help physicians screen RPS patients at high risk for postoperative complications and provide a basis for early intervention.

The mainstay of treatment for primary retroperitoneal sarcoma (RPS) is surgery. However, whether multiple visceral resection (MVR) affects patients’ quality of life compared with simple tumor resection has not been reported. Patients with primary RPS who underwent radical resection between 2009 and 2021 were included. Patients who were alive at the last follow-up were asked to complete the European Organization for the Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30). The primary endpoint of the study was the global health (GH) score. A total of 161 patients were included, including 77 in the MVR group and 84 in the non-MVR group. When comparing EORTC scores on functional domains and symptom scales between MVR and non-MVR groups, only constipation scores differed (p = 0.011). Comparing GH scores within 6 months after surgery between the two groups, GH was better in non-MVR patients (58.3 vs. 76.4, p = 0.082). However, patients with longer postoperative intervals in the MVR group had higher scores (p < 0.001), and patients with postoperative intervals of more than one year scored similar to those in the non-MVR group (64.7 vs. 59.2, p = 0.522). As the postoperative interval increased, there was an improvement in all indicators in MVR patients, while there was no significant improvement in non-MVR patients. Aggressive surgical approaches impair quality of life within 6 months postoperatively, but the long-term quality of life is similar to that of patients undergoing simple tumor resection. This should be factored into RPS treatment decisions.

Management of retroperitoneal sarcoma (RPS) involving the iliac artery is challenging and requires the concerted efforts of multidisciplinary team (MDT) members during surgical treatment. To summarize the clinicopathologic features of RPS involving the iliac artery and our retroperitoneal soft tissue tumor MDT surgical experience. In this retrospective study, 15 patients with RPS involving the iliac artery who underwent surgery at our retroperitoneal soft tissue tumor center from July 2004 to June 2020 were analyzed. Statistical analyses were performed by Student’s t-test with SPSS 16.0. Complete tumor resection (R0/R1) and iliac artery reconstruction were achieved in all 15 patients. All the operations were successful, with no serious complications or perioperative death. Resection with bilateral iliac artery reconstruction required a higher intraoperative blood transfusion volume than resection with unilateral iliac artery reconstruction. Recurrent cases were more likely to bleed and required a higher blood transfusion volume than primary cases. As of January 2021, 11 patients were alive, and 4 had died. Local recurrence occurred in two patients, one of whom developed liver metastasis. Resection of RPS involving iliac vessels is feasible and effective when performed by MDT members. Iliac artery oncovascular resection and reconstruction are key to a successful operation. Adequate blood preparation is important for successful completion of surgery.