BACKGROUND: The surgical treatment of retroperitoneal sarcoma (RPS) is highly challenging because of its complex anatomy. In this study, the authors compared the surgical outcomes of patients with RPS who underwent surgical resection guided by three-dimensional (3D) printing technology versus traditional imaging.
METHODS: This retrospective study included 251 patients who underwent RPS resection guided by 3D-printing technology or traditional imaging from January 2019 to December 2022. The main outcome measures were operative time, intraoperative blood loss, postoperative complications, and hospital stay.
RESULTS: In total, 251 patients were enrolled in the study: 46 received 3D-printed navigation, and 205 underwent traditional surgical methods. Propensity score matching yielded 44 patients in the 3D group and 82 patients in the control group. The patients\' demographics and tumor characteristics were comparable in the matched cohorts. The 3D group had significantly shorter operative time (median, 186.5 minutes [interquartile range (IQR), 130.0-251.3 minutes] vs. 210.0 minutes [IQR, 150.8-277.3 minutes]; p = .04), less intraoperative blood loss (median, 300.0 mL [IQR, 100.0-575.0 mL] vs. 375.0 mL [IQR, 200.0-925.0 mL]; p = .02), shorter postoperative hospital stays (median, 11.0 days [IQR, 9.0-13.0 days] vs. 14.0 days [IQR, 10.8-18.3 days]; p = .02), and lower incidence rate of overall postoperative complications than the control group (18.1% vs. 36.6%; p = .03). There were no differences with regard to the intraoperative blood transfusion rate, the R0/R1 resection rate, 30-day mortality, or overall survival.
CONCLUSIONS: Patients in the 3D group had favorable surgical outcomes compared with those in the control group. These results suggest that 3D-printing technology might overcome challenges in RPS surgical treatment.
CONCLUSIONS: The surgical treatment of retroperitoneal sarcoma (RPS) is highly challenging because of its complex anatomy. The purpose of this study was to investigate whether three-dimensional (3D) printing technology offers advantages over traditional two-dimensional imaging (such as computed tomography and magnetic resonance imaging) for guiding the surgical treatment of RPS. In a group of patients who had RPS, surgery guided by 3D-printing technology was associated with better surgical outcomes, including shorter operative time, decreased blood loss, shorter hospital stays, and fewer postoperative complications. These findings suggested that 3D-printing technology could help surgeons overcome challenges in the surgical treatment of RPS. 3D-printing technology has important prospects in the surgical treatment of RPS.

OBJECTIVE: Anthracycline-based chemotherapies including doxorubicin monotherapy are recommended in major guidelines for patients with advanced or metastatic retroperitoneal sarcoma (RPS); however, few studies have reported the outcomes of doxorubicin monotherapy for these patients. We herein investigated the oncological efficacy and safety of doxorubicin monotherapy for patients with advanced or metastatic RPS in real-world clinical practice.
METHODS: Sixteen patients diagnosed with advanced or metastatic retroperitoneal sarcoma, receiving doxorubicin monotherapy as first-line treatment between February 2017 and March 2023 at our Institution were analyzed. Response rate, progression-free survival (PFS) periods, overall survival (OS) period, and adverse event (AE) profiles were retrospectively investigated.
RESULTS: The median age of patients was 69.5 years. Best responses to doxorubicin were as follows: complete response, 0 patients (0.0%); partial response, 3 (18.8%); stable disease, 9 (56.3%); and progressive disease, 4 (25.0%). The objective response rate and disease control rate were 18.8 and 75.0%, respectively. During the observation period (median, 22 months, range=2-53 months), median PFS and OS periods were 8.0 and 24.0 months, respectively. The following AEs Grade ≥3 occurred: neutropenia in 14 patients (87.5%), febrile neutropenia in 5 (31.3%), leukopenia in 2 (12.5%), thrombocytopenia in 1 (6.3%), and heart failure in 1 (6.3%). Grade ≥3 nausea and vomiting did not occur and there was no treatment-related death.
CONCLUSIONS: The oncological outcomes of doxorubicin monotherapy for RPS in real-world clinical practice were not inferior to those of the EORTC trial. The incidence of hematological AEs was higher; however, severe gastrointestinal AEs were prevented by prophylactic antiemetics and there were no treatment-related deaths. Collectively, doxorubicin monotherapy with appropriate prophylactic agents is a valid option for patients with advanced or metastatic RPS.

BACKGROUND: Primary retroperitoneal sarcoma (RPS) comprises over 70 histologic subtypes, yet there are limited studies that have developed prognostic nomograms for RPS patients to predict overall survival (OS) and cancer-specific survival (CSS). The objective of this study was to construct prognostic nomograms for predicting OS and CSS in RPS patients.
METHODS: We identified a total of 1166 RPS patients from the Surveillance, Epidemiology and End Results (SEER) database, and an additional 261 cases were collected from a tertiary cancer center. The study incorporated various clinicopathological and epidemiologic features as variables, and prediction windows for overall survival (OS) and cancer-specific survival (CSS) were set at 3, 5, and 7 years. Multivariable Cox models were utilized to develop the nomograms, and variable selection was performed using a backward procedure based on the Akaike Information Criterion. To evaluate the performance of the nomograms in terms of calibration and discrimination, we used calibration plots, coherence index, and area under the curve.
RESULTS: The study included 818 patients in the development cohort, 348 patients in the internal validation cohort, and 261 patients in the external validation cohort. The backward procedure selected the following variables: age, French Federation of Cancer Centers Sarcoma Group (FNCLCC) grade, pre-/postoperative chemotherapy, tumor size, primary site surgery, and tumor multifocality. The validation results demonstrated that the nomograms had good calibration and discrimination, with C-indices of 0.76 for OS and 0.81 for CSS. Calibration plots also showed good consistency between the predicted and actual survival rates. Furthermore, the areas under the time-dependent receiver operating characteristic curves for the 3-, 5-, and 7-year OS (0.84, 0.82, and 0.78, respectively) and CSS (0.88, 0.88, and 0.85, respectively) confirmed the accuracy of the nomograms.
CONCLUSIONS: Our study developed accurate nomograms to predict OS and CSS in patients with RPS. These nomograms have important clinical implications and can assist healthcare providers in making informed decisions regarding patient care and treatment options. They may also aid in patient counseling and stratification in clinical trials.

BACKGROUND: To report the final results of a prospective, one-armed, single-center phase I/II trial (NCT01566123).
METHODS: Between 2007 and 2017, 37 patients with primary or recurrent (N = 6) retroperitoneal sarcomas were enrolled. Treatment included preoperative IMRT of 45-50 Gy with a simultaneous integrated boost of 50-56 Gy, surgery and IORT. The primary endpoint was local control (LC) at 5 years. The most common histology was dedifferentiated liposarcoma (51%), followed by leiomyosarcoma (24%) and well-differentiated liposarcoma (14%). The majority of lesions were high-grade (FNCLCC G1: 30%, G2: 38%, G3: 27%, two missing). Five patients were excluded from LC analysis per protocol.
RESULTS: The minimum follow-up of the survivors was 62 months (median: 109; maximum 162). IORT was performed for 27 patients. Thirty-five patients underwent gross total resection; the pathological resection margin was mostly R+ (80%) and, less often, R0 (20%). We observed 10 local recurrences. The 5-year LC of the whole cohort was 59.6%. Eleven patients received a dose > 50 Gy plus IORT boost; LC was 64.8%; the difference, however, was not significant (p = 0.588). Of 37 patients, 15 were alive and 22 deceased at the time of final analysis. The 5-year OS was 59.5% (68.8% per protocol).
CONCLUSIONS: The primary endpoint of a 5-year LC of 70% was not met. This might be explained by the inclusion of recurrent disease and the high rate of G3 lesions and leiomyosarcoma, which have been shown to profit less from radiotherapy. Stratification by grading and histology should be considered for future studies.

BACKGROUND: Retroperitoneal liposarcomas are locally aggressive and frequently recur following complete surgical resection. Palbociclib, a cyclin-dependent kinase (CDK) 4/CDK6 inhibitor, is effective in the treatment of metastatic or unresectable liposarcoma.
OBJECTIVE: The purpose of this study was to describe our initial experience using adjuvant palbociclib to delay recurrence.
METHODS: Patients with resected RPS were identified from a prospectively maintained institutional database. In 2017, we began offering adjuvant palbociclib to patients following complete gross resection. Treatment interval, defined as the time between surgical resection and re-resection or change in systemic therapy, was compared between patients selected for adjuvant palbociclib or observation.
RESULTS: Between 2017 and 2020, 12 patients underwent a total of 14 operations (14 patient cases) and were selected for adjuvant palbociclib for recurrence prevention. These patients were compared with 14 patients who, since 2010, underwent a total of 20 operations (20 patient cases) and were selected for observation. Histology was primarily dedifferentiated liposarcoma for both groups (observation: 70% [14/20]; adjuvant palbociclib: 64% [9/14]). All patients underwent complete gross resection. Neither age, number of previous surgeries, histologic grade, or Eastern Cooperative Oncology Group (ECOG) performance status differed between groups (p > 0.05 for all). Patients selected for adjuvant palbociclib experienced a longer treatment interval than those selected for observation, although it did not reach statistical significance (20.5 months vs. 13.1 months, p = 0.08, log rank).
CONCLUSIONS: Adjuvant palbociclib may be associated with a prolonged interval between liposarcoma resection and the need for re-resection or other systemic therapy. Palbociclib may be effective in delaying liposarcoma recurrence, and its use for this indication warrants prospective study.

Adipocytic tumours are the most common soft tissue neoplasms. Among them, liposarcoma is the most frequent malignant neoplasm. However, to the best of our knowledge, no previously published study has assessed the evolution and oncological prognosis of the different subtypes of liposarcoma at the retroperitoneal level compared with at other locations. The present study is a retrospective observational study in which all patients were operated on between October 2000 and January 2020 with a histological diagnosis of liposarcoma. Variables, such as age, sex, location, histological type, recurrence, type of treatment and mortality, among others, were analysed. The patients were divided into two groups: Group A (retroperitoneal location) and group B (non-retroperitoneal location). A total of 52 patients with a diagnosis of liposarcoma (17 women and 35 men) and a mean age of 57.2±15.9 years were assessed. A total of 16 patients were classified into group A and 36 into group B. The OR of recurrence was 1.5 (P=0.02) for R1 vs. R0 resection in group A. The OR of recurrence in group B for R1 vs. R0 resection was 1.8 (P=0.77), whereas for R2 vs. R0 resection, the OR was 69 (P=0.011). In conclusion, 52 cases of malignant adipocytic tumours collected during 2000-2020 were analysed with the new World Health Organization classification (updated 2020). Although its recurrence potential and capacity for distant metastasis depended on each histological type, surgical treatment with unaffected margins was the main prognostic factor for survival. The present study identified differences in relation to the survival of each histological subtype and its location, finding greater survival in dedifferentiated liposarcoma, myxoid liposarcoma and pleomorphic liposarcoma located at the extraperitoneal level than in the retroperitoneal location. Resectability was not influenced by liposarcoma location.

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.

BACKGROUND: The role of en bloc vascular resection and reconstruction (EVRR) is controversial in colorectal adenocarcinoma (CRC), but well-established in retroperitoneal sarcoma (RPS). Sparse data exists regarding these complex procedures.
METHODS: Patients undergoing curative intent EVRR for advanced CRC and RPS between 2014 and 2021 at a tertiary centre were included. Morbidity, margins, recurrence, and survival were evaluated.
RESULTS: 24 patients underwent EVRR with 48 reconstructions (11 CRC and 13 RPS). For CRC, 100% of patients underwent Iliac system reconstructions. For RPS, inferior vena cava reconstructions were the most common (69.2%). There were 2 arterial and 1 venous graft thromboses. Primary graft patency was 89.4% arterial and 93.1% venous, while secondary patency was 100% arterial and 96.5% venous at last follow up. 1 venous and 1 arterial graft required reoperation for bleeding. There were no compromised limbs. Major complications occurred in 6 patients (25.0%) with no observed difference between CRC and RPS (OR 0.43 95%CI[0.60,3.19], P = 0.41). R1 margins occurred 1 CRC (90.9%) and 3 RPS (76.9%), with no R2 resections. All vascular resection margins were clear. There were 6 CRC (50%) and 4 RPS (33.3%) recurrences. Median recurrence time was 20.9 months for CRC and \'not yet reached\' for RPS. Median follow-up was 19.4 months for CRC and 21.4 months for RPS.
CONCLUSIONS: EVRR for locally advanced CRC or RPS is safe and achieves favorable R0 resection rates. CRC patients with major vascular invasion can still be considered for curative intent surgery. Larger cohorts with longer follow up are needed to assess oncologic outcomes.

UNASSIGNED: Retroperitoneal sarcoma (RPS) is a rare disease often requiring multi-visceral and wide margin resections for which a resection in a sarcoma center is advised. Midline incision seems to be the access of choice. However, up to now there is no evidence for the best surgical access. This study aimed to analyze the oncological outcome according to the surgical expertise and also the incision used for the resection.
UNASSIGNED: All patients treated for RPS between 2007 and 2018 at the Department of Visceral Surgery and Medicine of the University Hospital Bern and receiving a RPS resection in curative intent were included. Patient- and treatment specific factors as well as local recurrence-free, disease-free and overall survival were analyzed in correlation to the hospital type where the resection occurred.
UNASSIGNED: Thirty-five patients were treated for RPS at our center. The majority received their primary RPS resection at a sarcoma center (SC = 23) the rest of the resection were performed in a non-sarcoma center (non-SC = 12). Median tumor size was 24 cm. Resections were performed via a midline laparotomy (ML = 31) or flank incision (FI = 4). All patients with a primary FI (n = 4) were operated in a non-SC (p = 0.003). No patient operated at a non-SC received a multivisceral resection (p = 0.004). Incomplete resection (R2) was observed more often when resection was done in a non-SC (p = 0.013). Resection at a non-SC was significantly associated with worse recurrence-free survival and disease-free survival after R0/1 resection (2 vs 17 months; Log Rank p-value = 0.02 respectively 2 vs 15 months; Log Rank p-value < 0.001).
UNASSIGNED: Resection at a non-SC is associated with more incomplete resection and worse outcome in RPS surgery. Inadequate access, such as FI, may prevent complete resection and multivisceral resection if indicated and demonstrates the importance of surgical expertise in the outcome of RPS resection.

The patient was a 45-year-old male who initially presented with a left hydrocele. During radiographic work-up, a 26 cm right retroperitoneal lipoma was incidentally discovered. Despite a recommendation for preoperative radiation therapy followed by surgery from the sarcoma multispecialty team, the patient opted for surgery alone, in the hopes of avoiding damage or loss of his right kidney. Following surgical excision of the 39 cm well-differentiated liposarcoma, with removal of the perinephric fat adjacent to the tumor thereby preserving the kidney, he was discharged home after two nights in the hospital. Follow-up imaging eight months later showed no recurrence.