Personalizing surgical margins in retroperitoneal sarcomas: an update

Progress in histology specific treatments in soft tissue sarcoma

INTRODUCTION

Soft tissue sarcomas (STS) represent a heterogenous group of rare tumors, primarily treated with surgery. Preoperative radiotherapy is often recommended for extremity high-risk STS. Neoadjuvant chemotherapy, typically based on doxorubicin with ifosfamide, has shown efficacy in limbs and trunk wall STS. Second-line chemotherapy, commonly utilized in the metastatic setting, is mostly histology-driven. Molecular targeted agents are used across various histologies, and although the use of immunotherapy in STS is still in its early stages, there is increasing interest in exploring its potential.

AREAS COVERED

This article involved an extensive recent search on PubMed. It explored the current treatment landscape for localized and metastatic STS, focusing on the combined use of radiotherapy and chemotherapy for both extremity and retroperitoneal tumors, and with a particular emphasis on the most innovative histopathology driven therapeutic approaches. Additionally, ongoing clinical trials identified via clinicaltrials.gov are included.

EXPERT OPINION

Recently there have been advancements in the treatment of STS, largely driven by the outcomes of clinical trials. However further research is imperative to comprehend the effect of chemotherapy, targeted therapy and immunotherapy in various STS, as well as to identify biomarkers able to predict which patients are most likely to benefit from these treatments.

Histology-Tailored Approach to Soft Tissue Sarcoma

Soft tissue sarcomas are a diverse and heterogeneous group of cancers of mesenchymal origin. Each histological type of soft tissue sarcoma has unique clinical particularities, which makes them challenging to diagnose and treat. Multidisciplinary management of these rare diseases is thus key for improved survival. The role of surgery has been well established, and it represents the cornerstone curative treatment for soft tissue sarcomas. To date, local recurrence is the leading cause of death in low-grade sarcomas located at critical sites, and distant metastasis in high-grade sarcomas, regardless of the site of origin. Management must be tailored to each individual histologic type. We describe the most common types of extremity, trunk, abdominal, and retroperitoneal soft tissue sarcoma along with characteristics to consider for optimized management.

Learning curve in retroperitoneal sarcoma surgery

INTRODUCTION

Retroperitoneal sarcoma (RPS) surgery poses unique challenges. This retrospective study aimed to analyze the learning curve (LC) in RPS surgery, assessing the relationship between surgical experience and outcomes.

MATERIALS AND METHODS

Cumulative sum (CUSUM) analysis was used to analyze 62 RPS surgeries performed by a single surgeon between 2016 and 2022 at our center.

RESULTS

The number of cases where the surgeon acted as first operator increased from 3 in 2016 to 13 in 2022. The surgeon operated with his mentor in 66.7 % of cases in 2016, whereas in 7.7 % of cases in 2022. LC consisted of 3 phases. Phase 1 (16 cases), with a negative slope, represented shorter operative time (OT) and fewer number of resected organs (RO). Phase 2 (30 cases) was the plateau phase. Phase 3 (16 cases), with a positive slope, indicated longer OT and more RO. Statistically significant differences were observed in terms of size (p = 0.003), presentation (p = 0.048), number of resected organs (p = 0.046), pattern of resection (p = 0.033), OT (p = 0.006), and length of stay (p = 0.026) between the three phases.

CONCLUSION

This study focused on the critical role of LC in RPS surgery, emphasizing its influence on outcomes. We identified three phases, highlighting the surgeon's evolution. This offers a framework for educating sarcoma surgeons and ensuring exposure to increasing surgical complexity. In discussions on sarcoma referral centers and the correlation between case volume and outcomes, this study underlines the importance of evaluating LC to distinguish surgeons qualified to manage sarcoma cases within a referral center.

Ibero-American Consensus for the Management of Peritoneal Sarcomatosis: Updated Review and Clinical Recommendations

Peritoneal sarcomatosis is a rare malignant disease with a poor prognosis, secondary to peritoneal dissemination of abdominopelvic soft tissue sarcomas. Its rarity, together with the characteristic histological heterogeneity and the historically poor response to systemic treatments, has prevented the establishment of widely accepted treatment criteria with curative intent. In this sense, radical cytoreductive surgery (CRS) with peritonectomy procedures and hyperthermic intraperitoneal chemotherapy (HIPEC), widely used in peritoneal carcinomatosis with excellent results, have not had the same evolutionary development in patients with peritoneal sarcomatosis. A multidisciplinary working group of experts in sarcomas and peritoneal oncological surgery established a series of recommendations based on current scientific evidence for the management of peritoneal sarcomatosis, taking into account the different histological subgroups of abdominopelvic sarcomas that can cause it depending on their origin: retroperitoneal sarcomas, uterine sarcomas, and visceral/peritoneal sarcomas of GIST (gastrointestinal stromal tumor) and non-GIST origin. This article shows the results of sarcoma experts' voting on the recommendations presented during the I Ibero-American Consensus on the Management of Peritoneal Sarcomatosis, which took place during the recent celebration of the III Hispanic-Portuguese Meeting for Updates on the Treatment of Sarcomas.

Optimizing surgical strategies for retroperitoneal liposarcoma: a comprehensive evaluation of standardized aggressive surgical policies

BACKGROUND

Retroperitoneal liposarcoma (RLPS) constitutes the majority of retroperitoneal sarcomas. While surgical resection remains the sole curative approach, determining the optimal surgical strategy for RLPS remains elusive. This study addresses the ongoing debate surrounding the optimal surgical strategy for RLPS.

METHODS

We recruited 77 patients with RLPS who underwent aggressive surgical policies. Patients were categorized into three surgical subtypes: suprapancreatic RLPS, pancreatic RLPS, and subpancreatic RLPS. Our standardized surgical strategy involved resecting macroscopically uninvolved adjacent organs according to surgical subtypes. We collected clinical, pathological and prognostic data for analyses.

RESULTS

The median follow-up was 45.5 months. Overall survival (OS) and recurrence-free survival (RFS) were significantly correlated with multifocal RLPS, pathological subtype, recurrent RLPS and histological grade (P for OS = 0.011, 0.004, 0.010, and < 0.001, P for RFS = 0.004, 0.001, < 0.001, and < 0.001, respectively). The 5-Year Estimate OS of well-differentiated liposarcoma (WDLPS), G1 RLPS, de novo RLPS and unifocal RLPS were 100%, 89.4%, 75.3% and 69.1%, respectively. The distant metastasis rate was 1.4%. The morbidity rates (≥ grade III) for suprapancreatic, pancreatic, and subpancreatic RLPS were 26.7%, 15.6%, and 13.3%, respectively. The perioperative mortality rate is 2.6%.

CONCLUSIONS

Standardized aggressive surgical policies demonstrated prognostic benefits for RLPS, particularly for G1 RLPS, WDLPS, unifocal RLPS, and de novo RLPS. This approach effectively balanced considerations of adequate exposure, surgical safety, and thorough removal of all fat tissue. G1 RLPS, WDLPS, unifocal RLPS, and de novo RLPS could be potential indications for aggressive surgical policies.

Contemporary Approach to Neurofibromatosis Type 1-Associated Malignant Peripheral Nerve Sheath Tumors

Most malignant peripheral nerve sheath tumors (MPNSTs) are clinically aggressive high-grade sarcomas, arising in individuals with neurofibromatosis type 1 (NF1) at a significantly elevated estimated lifetime frequency of 8%-13%. In the setting of NF1, MPNSTs arise from malignant transformation of benign plexiform neurofibroma and borderline atypical neurofibromas. Composed of neoplastic cells from the Schwannian lineage, these cancers recur in approximately 50% of individuals, and most patients die within five years of diagnosis, despite surgical resection, radiation, and chemotherapy. Treatment for metastatic disease is limited to cytotoxic chemotherapy and investigational clinical trials. In this article, we review the pathophysiology of this aggressive cancer and current approaches to surveillance and treatment.

UK guidelines for the management of soft tissue sarcomas

Soft tissue sarcomas (STS) are rare tumours arising in mesenchymal tissues and can occur almost anywhere in the body. Their rarity, and the heterogeneity of subtype and location, means that developing evidence-based guidelines is complicated by the limitations of the data available. This makes it more important that STS are managed by expert multidisciplinary teams, to ensure consistent and optimal treatment, recruitment to clinical trials, and the ongoing accumulation of further data and knowledge. The development of appropriate guidance, by an experienced panel referring to the evidence available, is therefore a useful foundation on which to build progress in the field. These guidelines are an update of the previous versions published in 2010 and 2016 [1, 2]. The original guidelines were drawn up by a panel of UK sarcoma specialists convened under the auspices of the British Sarcoma Group (BSG) and were intended to provide a framework for the multidisciplinary care of patients with soft tissue sarcomas. This iteration of the guidance, as well as updating the general multidisciplinary management of soft tissue sarcoma, includes specific sections relating to the management of sarcomas at defined anatomical sites: gynaecological sarcomas, retroperitoneal sarcomas, breast sarcomas, and skin sarcomas. These are generally managed collaboratively by site specific multidisciplinary teams linked to the regional sarcoma specialist team, as stipulated in the recently published sarcoma service specification [3]. In the UK, any patient with a suspected soft tissue sarcoma should be referred to a specialist regional soft tissues sarcoma service, to be managed by a specialist sarcoma multidisciplinary team. Once the diagnosis has been confirmed using appropriate imaging and a tissue biopsy, the main modality of management is usually surgical excision performed by a specialist surgeon, combined with pre- or post-operative radiotherapy for tumours at higher risk for local recurrence. Systemic anti-cancer therapy (SACT) may be utilised in cases where the histological subtype is considered more sensitive to systemic treatment. Regular follow-up is recommended to assess local control, development of metastatic disease, and any late effects of treatment.

Anesthetic managements, morbidities and mortalities in retroperitoneal sarcoma patients experiencing perioperative massive blood transfusion

Objective

Given high risks of major bleeding during retroperitoneal sarcoma(RPS) surgeries, severe complications and deaths are common to see perioperatively. Thus, effective anesthetic management is the key point to ensuring the safety of patients. This study aimed to introduce anesthesia management and mortalities in RPS patients receiving massive blood transfusions during surgeries.

Methods

Records of RPS surgeries under general anesthesia from January 2016 through December 2021 were retrospectively retrieved from our database. Patients who received massive blood transfusions (MBT) exceeding 20 units in 24h duration of operations were finally included in this study. Demographics, modalities of anesthesia management, blood loss, transfusion, peri-anesthesia biochemical tests as well as morbidities and mortalities were collected. Risk factors of postoperative 60d mortality were determined through logistic regression in uni-and multi-variety analysis using the statistics software STATA 17.0.

Results

A total of 70 patients (male 31) were included. The mean age was 50.1 ± 15.8 years. All patients received combined resections of sarcoma with involved organs under general anesthesia. Mean operation time and anesthesia time were 491.7 ± 131.1mins and 553.9 ± 132.6mins, respectively. The median intraoperative blood loss was 7000ml (IQR 5500,10000ml). Median red blood cells (RBC) and fresh frozen plasma (FFP) transfusion were 25.3u (IQR 20,28u), and 2400ml (IQR 2000,3000ml), respectively. Other blood products infusions included prothrombin complex concentrate (PCCs), fibrinogen concentrate (FC), platelet(plt) and albumin(alb) in 82.9% (58/70), 88.6% (62/70), 81.4% (57/70) and 12.9% (9/70) of patients. The postoperative severe complication rate(Clavien-Dindo grade≥3a) was 35.7%(25/70). A total of 7 patients (10%) died during the postoperative 60-day period. BMI, volumes of crystalloid infusion in anesthesia, and hemoglobin and lactate levels at the termination of operation were found significantly associated with postoperative occurrence of death in univariate analysis. In logistic multivariate analysis, extended anesthesia duration was found associated with postoperative venous thrombosis embolism (VTE) and severe complication. The lactate level at the immediate termination of the operation was the only risk factor related to perioperative death (p<0.05).

Conclusion

RPS patients who endure MBT in surgeries face higher risks of death postoperatively, which needs precise and effective anesthesia management in high-volume RPS centers. Increased blood lactate levels might be predictors of postoperative deaths which should be noted.

Long-term quality of life after resection of retroperitoneal soft tissue sarcoma

INTRODUCTION

Retroperitoneal soft tissue sarcoma (RPS) is characterized by high recurrence rates. Since complete tumor resection, often necessitating multivisceral resection, enables long-term survival in both primary and recurrent disease, health related quality of life (QoL) after RPS resection has attracted increasing interest. However, data regarding this topic is limited. Here, we multidimensionally assessed long-term QoL after RPS resection.

METHODS

Five previously validated (1. EORTC QLQ-C30, 2. WEMWBS, 3. FoP-Q-SF, 4. PC-PTSD, 5. Pro-CTCAE) were sent to patients having undergone resection of primary, recurrent and metastasized RPS at Heidelberg University Hospital between 10/2001 and 12/2020. Multivariable linear regression models were used to test associations between clinical/demographic variables and patient reported outcomes (PROs).

RESULTS

Questionnaires were answered by 127 patients (71% response rate). The median interval between RPS diagnosis and assessment of PROs was 80 months. The overall Global Health score was 64.1 and comparable to the general German population. RPS patients reported deficits regarding emotional and social functioning, whereas physical limitations were less pronounced. Besides diarrhea, abdominal symptoms were comparable to the overall population. Tumor recurrences, the number of surgeries, multivisceral resections or postoperative complications did not significantly affect long-term QoL ratings.

CONCLUSION

RPS patients rate their QoL relatively high, even after multiple and multivisceral resections. Psychosocial well-being should be monitored in follow-up sessions to offer tailored support if necessary, thus improving postoperative care.

Aggressive surgical approach with vascular resection and reconstruction for retroperitoneal sarcomas: a systematic review

BACKGROUND AND AIM

Surgery is the mainstay of treatment and completeness of surgical resection is critical to achieve local control for retroperitoneal sarcoma (RPS). En-bloc resection of adjacent organs, including major abdominal vessels, is often required to achieve negative margins. The aim of this review was to summarise the available evidence to assess the relative benefits and disadvantages of an aggressive surgical approach with vascular resection in patients with retroperitoneal sarcoma (RPS).

METHODS

We searched PubMed, the Cochrane Library, and EMBASE for relevant studies published from inception up to August 1, 2022. We performed a systematic review of the available studies to assess the safety and long-term survival results of vascular resection for RPS.

RESULTS

We identified a total of 23 studies for our review. Overall postoperative in-hospital or 30-day mortality rate of patients with primary iliocaval leiomyosarcoma was 3% (11/359), and the major complication rate was 13%. The recurrence-free survival (RFS) rates after the follow-up period varied between 15% and 52%, and the 5-year overall survival (OS) rates ranged from 25 to 78%. Overall postoperative in-hospital or 30-day mortality rate of patients with RPSs receiving vascular resection was 3%, and the major complication rate was 27%. The RFS rates after the follow-up period were 18-86%, and the 5-year OS rates varied between 50% and 73%. There were no significant differences in the rates of RFS (HR: 0.97; 95% CI: 0.74-1.19; p = 0.945) and OS (HR: 1.01; 95% CI: 0.66-1.36; p = 0.774) between the extended resection group and tumour resection alone group.

CONCLUSIONS

With adequate preparation and proper management, for patients with RPSs involving major vessels, aggressive surgical approach with vascular resection can achieve R0/R1 resection and improve survival.

Organ Infiltration and Patient Risk After Multivisceral Surgery for Primary Retroperitoneal Liposarcomas

BACKGROUND

The extent of histological organ involvement (HOI) to organs and structures of a retroperitoneal liposarcoma may have prognostic implications. This study investigated incidence, characteristics, and risk association of HOI in these patients.

PATIENTS AND METHODS

Data of patients who underwent multivisceral resection for primary liposarcoma (2009-2014) were retrospectively analyzed. HOI was the variable of interest and was classified into four degrees: absent (HOI-0), perivisceral (HOI-1), initial (HOI-2), and advanced (HOI-3). Primary endpoint was overall survival (OS). Secondary endpoint was disease-free survival (DFS). The prognostic value of HOI was adjusted for preoperative treatment and the Sarculator nomogram score.

RESULTS

A total of 109 patients were included. HOI-0, HOI-1, HOI-2, and HOI-3 were detected in 9 (8.3%), 11 (10.1%), 43 (39.4%), and 46 (42.2%) patients. Median follow-up was 8.4 years [interquartile range (IQR) 7.2-9.6 years]. There were 68 recurrences and 50 patient deaths observed, resulting in a 10-year OS and DFS of 51.1% [95% confidence interval (CI) 41.9-62.1%] and 34.1% (95% CI 25.2-46.1%), respectively. Clinically relevant HOIs (HOI-2 and HOI-3) were found in 35/45 (77.8%) and 54/64 (84.4%) cases of well- and de-differentiated liposarcomas, respectively. On multivariable survival analysis, patients with HOI-3 had significantly shorter OS (HOI-3 vs HOI-0/HOI-1 HR 2.92; p = 0.012) and DFS (HOI-3 vs HOI-0/HOI-1 HR 2.23; p = 0.045), independently of the nomogram score (OS: HR 2.93; p < 0.001; DFS: HR 1.78; p = 0.003).

CONCLUSIONS

Initial and advanced HOIs are frequently detected in both well-differentiated and de-differentiated liposarcomas, supporting that multivisceral resection may be needed. HOI stratifies the risk of patients with primary retroperitoneal liposarcoma.

Next questions in the management of retroperitoneal sarcoma

PURPOSE OF REVIEW

Retroperitoneal soft-tissue sarcomas (RPS) are a group of rare, histologically distinct tumours with variable recurrence patterns depending on histological type. This review will discuss the growing body of evidence supporting histology-specific, multidisciplinary management and highlight areas of future research for patients with RPS.

RECENT FINDINGS

Histology-tailored surgery is the cornerstone of management in patients with localized RPS. Further efforts to develop resectability criteria and identify patients who will benefit from neoadjuvant treatment strategies will help standardize the treatment of patients with localized RPS. Surgery for local recurrence is well tolerated in selected patients and re-iterative surgery in liposarcoma (LPS) may be beneficial at the time of local recurrence. The management of advanced RPS holds promise with several trials currently investigating systemic treatment beyond conventional chemotherapy.

SUMMARY

The management of RPS has made significant progress over the past decade owing to international collaboration. Ongoing efforts to identify patients who will derive the most benefit from all treatment strategies will continue to advance the field of RPS.

Preoperative Neutrophil-to-Lymphocyte Ratio and a New Inflammatory Biomarkers Prognostic Index for Primary Retroperitoneal Sarcomas: Retrospective Monocentric Study

PURPOSE

Inflammatory biomarkers and neutrophil-to-lymphocyte ratio (NLR) are associated with prognosis in several tumors. Data on sarcomas are limited, and insufficient on retroperitoneal sarcoma (RPS).

EXPERIMENTAL DESIGN

Patients with primary RPS operated between 2002 and 2016 were included. Hemoglobin, monocytes, NLR, platelet-to-lymphocyte ratio (PLR) were retrieved and analyzed both individually and combined into a prognostic index (IBPI). Correlation with clinicopathologic variables was studied, as well as postoperative morbidity according to NLR and IBPI risk categories. The association between overall survival (OS) and biomarkers and, in addition, the 7-year Sarculator-predicted OS probability (pOS) was analyzed using univariable and multivariable Cox models.

RESULTS

423/463 patients had complete data. The median follow-up was 84 months. The median NLR was 3.3 (IQR, 2.4-4.7), with significant variation across histologies. NLR was the only biomarker that independently predicted OS (HR, 1.2; 95% CI, 1.03-1.40; P = 0.02). The IBPI showed good discrimination for subgroups at different OS (log-rank test P < 0.0001). The Cox model for pOS alone showed a 7-year index of prediction accuracy of 26.9, which increased to 29.5 when IBPI was added to pOS as a complementary prognostic tool. IBPI was also associated with the risk of serious infectious postoperative complications (P = 0.0094; noninfectious complications, P = 0.6463).

CONCLUSIONS

NLR was an independent prognostic factor for OS in RPS. When combined into a prognostic index with hemoglobin, monocytes, and PLR, it serves as a readily available prognostic tool addressing tumor-related inflammation and helps in classifying RPS risk in addition to the Sarculator nomogram.

Giant retroperitoneal liposarcoma measuring 27 × 29 × 36 cm: a case report

Retroperitoneal tumors are rare neoplasms that can reach great dimensions due to a slow growth pattern. Although these tumors rarely metastasize, they have a great risk of recurrence, and majority of times these lesions are a challenge for the surgeon. We report the case of a 63-year-old woman who presented with symptoms of large bowel obstruction and was diagnosed with a large heterogenous mass located in the retroperitoneal space. The fine needle biopsy revealed the histology of liposarcoma. The purpose of this article is to report our approach in management of this kind of tumor. Tumor size (27.1 × 29.1 × 36.1 cm) and involvement to the adjacent organs was a challenge for us in order to reach safe oncological margins. In these cases, the risk of recurrence is high; therefore, the patient should be screened at 6, 12 and 24 months post procedure. Chemotherapy or radiotherapy for this tumor is not yet defined, and if operable, surgery is the treatment of choice.

Analysis of potential risk factors in the survival of patients with primary retroperitoneal liposarcoma

INTRODUCTION

The present work is an observational study of a series of variables regarding overall survival and disease-free survival in patients diagnosed with primary liposarcoma.

METHODS

The study is prospective with retrolective data collection that includes all patients with primary liposarcoma referred to Hospital Son Espases University Hospital, Palma de Mallorca, Spain from January 1990 to December 2019.

RESULTS

The study includes 50 patients and the compartment surgery was performed in 18 patients (36%) of cases. The mean overall survival of the sample was 15.57 years (95% CI: 12.02-19.12) and the mean disease-free survival was 6.70 years (95% CI: 4.50-8.86).

CONCLUSION

Compartment surgery has not shown benefits in terms of overall survival and disease-free survival. The ASA classification (≥3) predicts a poor prognosis in both overall survival and disease-free survival. Resection with free margins, described on the pathological results and defined in this work as R0, show better disease-free survival.

Prognosis and survival of patients diagnosed with well-differentiated and dedifferentiated retroperitoneal liposarcoma

OBJECTIVES

The main objective is to establish the overall survival and disease-free survival profiles regarding the patients with retroperitoneal liposarcoma, making a comparison based on the well-differentiated and dedifferentiated histological subtypes. The secondary objectives are to descriptively analyze the clinical characteristics of said patients and to identify and analyze other independent variables that might modify these survival profiles significantly.

METHODS

An observational and analytical study was performed using a retrospective historical cohort that was followed prospectively. The inclusion criteria consisted of: the procedure of liposarcoma located in the retroperitoneum, the well-differentiated and dedifferentiated histological subtypes, between January of 2002 and May of 2019. As a result, 32 patients took part in this study's sample. Kaplan-Meier estimator was used to summarise the results and log-rank test was used in the comparative analysis.

RESULTS

The overall survival at 5 years was around 59%. No differences were found between the patients with a well-differentiated subtype compared to the dedifferentiated ones (p = 0.834). The disease-free survival at 2 years was 59% regarding the well-differentiated and 26% regarding the dedifferentiated, with these differences being statistically significant (p = 0.005). None of the other studied variables modified these survival profiles significantly.

CONCLUSIONS

Dedifferentiated retroperitoneal liposarcomas show less disease-free survival than well-differentiated liposarcomas. However, regarding overall survival no differences can be claimed.

Surgical Principles of Primary Retroperitoneal Sarcoma in the Era of Personalized Treatment: A Review of the Frontline Extended Surgery

Simple Summary

Surgery is the only curative treatment for localized disease in retroperitoneal sarcoma (RPS). Frontline extended surgery, or compartmental surgery, is a recent surgical strategy consisting of resecting the tumor together with adjacent organs, with the aim of minimizing marginality. This review provides a practical step by step description of this standardized procedure, tailored to histologic behavior, tumor localization, and patient condition.

Abstract

Surgery is the key treatment in retroperitoneal sarcoma (RPS), as completeness of resection is the most important prognostic factor related to treatment. Compartmental surgery/frontline extended approach is based on soft-tissue sarcoma surgical principles, and involves resecting adjacent viscera to achieve a wide negative margin. This extended approach is associated with improved local control and survival. This surgery must be tailored to tumor histology, tumor localization, and patient performance status. We herein present a review of compartmental surgery principles, covering the oncological and technical basis, and describing the tailored approach to each tumor subtype and localization in the retroperitoneum.

A systematic review of margin status in retroperitoneal liposarcomas: Does the R0 margin matter?

Retroperitoneal liposarcomas (RPLPSs) are a rare tumor group for which current guidelines recommend aggressive en bloc resection to attain microscopically negative (R0) margins. To ensure R0 margins, resection of adherent or adjacent organs is often required. However, it is still unclear if R0 margins confer any additional benefit to patients over a grossly negative but microscopically positive (R1) margin. We performed a systematic search of PubMed and Embase databases for studies including patients receiving R0 or R1 resection for RPLPS. Nine retrospective cohort studies, one prospective cohort study, and 49 case reports/case series were included. A total of 552 patients with RPLPS were evaluated: 346 underwent R0 resection and 206 underwent R1 resection. In the R0 group, 5-year overall survival (OS) ranged from 58.3% to 85.7%; local recurrence (LR) ranged from 45.5% to 52.3%. In the R1 group, 5-year OS ranged from 35% to 55.3%; LR ranged from 66.7% to 91.7%. Among cohort studies, OS, disease-free survival (DFS), LR rate, and LR-free survival (LRFS) were significantly associated with R0 resections. Assessment of case series and reports suggested that the R0 margin led to a slightly higher morbidity than that of R1. In conclusion, this review found the R0 margin to be associated with reductions in LR rates and improved OS when compared with the R1 margins, though accompanied by slight increases in morbidity. The roles of tumor histotype and perioperative chemotherapy or radiotherapy were not well-elucidated in this review.

A novel nomogram model to predict the overall survival of patients with retroperitoneal leiomyosarcoma: a large cohort retrospective study

Retroperitoneal leiomyosarcomas (RLS) are the second most common type of retroperitoneal sarcoma and one of the most aggressive tumours. The lack of early warning signs and delay in regular checkups lead to a poor prognosis. This study aims to create a nomogram to predict RLS patients' overall survival (OS). Patients diagnosed with RLS in the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2018 were enrolled in this study. First, univariable and multivariable Cox regression analyses were used to identify independent prognostic factors, followed by constructing a nomogram to predict patients' OS at 1, 3, and 5 years. Secondly, the nomogram's distinguishability and prediction accuracy were assessed using receiver operating characteristic (ROC) and calibration curves. Finally, the decision curve analysis (DCA) investigated the nomogram's clinical utility. The study included 305 RLS patients, and they were divided into two groups at random: a training set (216) and a validation set (89). The training set's multivariable Cox regression analysis revealed that surgery, tumour size, tumour grade, and tumour stage were independent prognostic factors. ROC curves demonstrated that the nomogram had a high degree of distinguishability. In the training set, area under the curve (AUC) values for 1, 3, and 5 years were 0.800, 0.806, and 0.788, respectively, while in the validation set, AUC values for 1, 3, and 5 years were 0.738, 0.780, and 0.832, respectively. As evidenced by the calibration curve, the nomogram had high prediction accuracy. Moreover, DCA revealed that the nomogram had high clinical utility. Furthermore, the risk stratification system based on the nomogram could effectively categorise patients into three mortality risk subgroups. Therefore, the developed nomogram and risk stratification system may aid in optimising the treatment decisions of RLS patients to improve treatment prognosis and maximise their healthcare outcomes.

Toward Better Understanding and Management of Solitary Fibrous Tumor

Solitary fibrous tumor (SFT) comprises a histologic spectrum of soft tissue neoplasms that are characterized by the unique NAB2-STAT6 gene fusion. Changes in diagnostic terminology and site-specific classification over the past few decades have resulted in a disjointed literature. Complete surgical excision with preservation of function remains the mainstay of treatment. New risk stratification systems including risk factors such as mitotic rate, age, tumor size, and presence of necrosis, among others, can be used to predict risk of recurrence or metastasis. Long-term follow-up after surgical resection is recommended. The clinical manifestations, diagnosis, management, and prognosis of SFT are reviewed here.

Management of Locally Recurrent Retroperitoneal Sarcoma in the Adult: An Updated Consensus Approach from the Transatlantic Australasian Retroperitoneal Sarcoma Working Group

BACKGROUND

Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS.

METHODS

An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor.

RESULTS

Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS.

CONCLUSIONS

Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery.

The Role of Surgical Expertise and Surgical Access in Retroperitoneal Sarcoma Resection – A Retrospective Study

Background

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.

Methods

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.

Results

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 &lt; 0.001).

Conclusions

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.

Residual Adrenal Function After Multivisceral Resection With Adrenalectomy in Adult Patients

Importance

The risk of developing adrenal insufficiency (AI) following adrenalectomy has been insufficiently studied in the context of multivisceral resection (MVR).

Objective

To evaluate the incidence of AI in patients undergoing MVR with en bloc adrenalectomy.

Design, Setting, and Participants

Prospective observational longitudinal study in a single referral center including 56 consecutive adult patients undergoing retroperitoneal sarcoma surgery from June 2019 to August 2020. Those who were candidates for MVR with en bloc adrenalectomy and had no preexisting adrenal impairment were considered eligible. Of these, 4 individuals were excluded because they did not receive adrenalectomy at the time of surgery and 2 because they were not considered evaluable for the main end point. Follow-up was set at 4 months after surgery, and 49 patients completed follow-up. Data were analyzed from October 2020 to September 2021.

Exposures

Diagnosis of AI was determined by low-dose (1 μg) adrenocorticotropic hormone (ACTH) stimulation test with a threshold of 20 μg/dL in blood samples retrieved 30 and 60 minutes after stimulation. ACTH test was repeated on postoperative days 1 and 10 and at 4 months' follow-up.

Main Outcome and Measures

The primary end point was incidence and relevance of AI after MVR. Secondary end points were associations with patient- and tumor-related factors, impact on perioperative hemodynamic management, and association with postoperative morbidity and mortality.

Results

Fifty patients (26 female; median [IQR] age, 59 [46-67] years) were evaluable. Incidence of AI was 64% (32 of 50 patients) in the early postoperative period and 38.5% (15 of 39 patients) at follow-up. Patients with AI showed lower postoperative cortisol values. Factors associated with risk of AI at univariate analysis were high American Society of Anesthesiologists score (odds ratio [OR], 0.31; 95% CI, 0.14-0.48) and high malignancy grade (OR, 0.35; 95% CI, 0.24-0.46). Clinical outcomes not associated with AI included morbidity, mortality, reoperation rate, admission to intensive care unit, length of intensive care unit stay, total hospital stay, and long-term quality of life.

Conclusions and Relevance

In this study, AI after MVR with en bloc adrenalectomy was frequent, even in patients with adequate preoperative adrenal function. Despite this, adrenalectomy can be safely performed. Patients at risk should be monitored in the long term to exclude underrated impairment of adrenal function.

Retroperitoneal Sarcoma Care in 2021

Soft-tissue sarcomas are biologically heterogenous tumors arising from connective tissues with over 100 subtypes. Although sarcomas account for <1% of all adult malignancies, retroperitoneal sarcomas are a distinct subgroup accounting for <10% of all sarcomatous tumors. There have been considerable advancements in the understanding and treatment of retroperitoneal sarcoma in the last decade, with standard treatment consisting of upfront primary surgical resection. The evidence surrounding the addition of radiation therapy remains controversial. There remains no standard with regards to systemic therapy, including immunotherapy. Adjunctive therapy remains largely dictated by expert consensus and preferences at individual centers or participation in clinical trials. In this 2021 review, we detail the anatomical boundaries of the retroperitoneum, clinical characteristics, contemporary standard of care and well as recent advancements in retroperitoneal sarcoma care. Ongoing international collaborations are encouraged to advance our understanding of this complex disease.

[Retroperitoneal soft tissue sarcoma: surgical management]

BACKGROUND

Retroperitoneal soft tissue sarcomas are rare and heterogeneous tumors with high recurrence rates that require a multimodal treatment approach and a surgical resection strategy adapted to tumor localization and histological subtype.

OBJECTIVE

Based on current scientific data this article intends to provide an overview on subtype-specific features, prognostic factors and operative techniques in the surgical management of retroperitoneal soft tissue sarcomas.

MATERIAL AND METHODS

A review of the literature addressing surgical management of retroperitoneal soft tissue sarcomas was performed. Current evidence and recommendations were summarized.

RESULTS AND CONCLUSION

Macroscopically complete tumor resection represents the sole curative treatment option for both primary and recurrent retroperitoneal soft tissue sarcomas. To minimize the probability of tumor-infiltrated resection margins, compartmental resection has become a standard treatment for retroperitoneal soft tissue sarcomas. This approach includes resection of all organs and structures adjacent to the tumor. Multivisceral resection is often associated with this approach and it is acceptable in terms of morbidity and mortality if performed at a center with experience in retroperitoneal sarcoma surgery. Histologic subtype, tumor grading, and quality of initial surgical treatment are major prognostic factors for oncologic overall survival.

Analysis of potential risk factors in the survival of patients with primary retroperitoneal liposarcoma

INTRODUCTION

The present work is an observational study of a series of variables regarding overall survival and disease-free survival in patients diagnosed with primary liposarcoma.

METHODS

The study is prospective with retrolective data collection that includes all patients with primary liposarcoma referred to Hospital Son Espases University Hospital, Palma de Mallorca, Spain from January 1990 to December 2019.

RESULTS

The study includes 50 patients and the compartment surgery was performed in 18 patients (36%) of cases. The mean overall survival of the sample was 15.57 years (95% CI: 12.02-19.12) and the mean disease-free survival was 6.70 years (95% CI: 4.50-8.86).

CONCLUSION

Compartment surgery has not shown benefits in terms of overall survival and disease-free survival. The ASA classification (≥3) predicts a poor prognosis in both overall survival and disease-free survival. Resection with free margins, described on the pathological results and defined in this work as R0, show better disease-free survival.

Prognosis and survival of patients diagnosed with well-differentiated and dedifferentiated retroperitoneal liposarcoma

OBJECTIVES

The main objective is to establish the overall survival and disease-free survival profiles regarding the patients with retroperitoneal liposarcoma, making a comparison based on the well-differentiated and dedifferentiated histological subtypes. The secondary objectives are to descriptively analyze the clinical characteristics of said patients and to identify and analyze other independent variables that might modify these survival profiles significantly.

METHODS

An observational and analytical study was performed using a retrospective historical cohort that was followed prospectively. The inclusion criteria consisted of: the procedure of liposarcoma located in the retroperitoneum, the well-differentiated and dedifferentiated histological subtypes, between January 2002 and May 2019. As a result, 32 patients took part in this study's sample. Kaplan-Meier estimator was used to summarize the results and log-rank test was used in the comparative analysis.

RESULTS

The overall survival at 5 years was around 59%. No differences were found between the patients with a well-differentiated subtype compared to the dedifferentiated ones (p=0.834). The disease-free survival at 2 years was 59% regarding the well-differentiated and 26% regarding the dedifferentiated, with these differences being statistically significant (p=0.005). None of the other studied variables modified these survival profiles significantly.

CONCLUSIONS

Dedifferentiated retroperitoneal liposarcomas show less disease-free survival than well-differentiated liposarcomas. However, regarding overall survival no differences can be claimed.

Dedifferentiation within well-differentiated liposarcoma of the extremity or trunk: Implications for clinical management

BACKGROUND

In extremity or trunk liposarcoma, the implications of a dedifferentiated (DD) component within a well-differentiated (WD) tumor are unclear. We evaluated outcomes after surgery and identified potential predictors of survival in these patients compared to those with an entirely WD tumor.

METHODS

Retrospective data were collected for patients who underwent complete resection from 2009 to 2019. Cumulative incidences of local recurrence (LR) and distant metastasis (DM) were calculated, and overall survival (OS) was estimated. Associations between OS and clinicopathologic variables were evaluated by univariable models.

RESULTS

A total of 210 patients with MDM2-verified tumors were studied, including 58 (27.6%) with DD. In primary disease, LR occurred only in DD and worse OS was observed versus WD (p < 0.001). In recurrent disease, the LR incidences were similar between WD and DD (p = 0.559); however, worse OS persisted in DD (p = 0.004). The incidence of DM was extremely low (3.8%) and limited to DD. Higher grade (p < 0.001) and DD size (p = 0.043), but not overall tumor size were associated with worse OS.

CONCLUSIONS

In extremity or trunk liposarcoma, the presence of DD leads to significantly worse outcomes in both primary and recurrence diseases. Further study is needed to determine if these patients benefit from adjunct therapies (e.g., radiation).

Oncological outcomes after major vascular resections for primary retroperitoneal liposarcoma

BACKGROUND

The surgical management of retroperitoneal sarcomas frequently involves complex multivisceral resections, however retroperitoneal liposarcoma (LPS) rarely invade major abdominal vessels. The aim of the study was to assess association of major vascular resections with outcome of primary LPS.

METHODS

All consecutive patients who underwent resection at our institutions for primary LPS between 2002 and 2019 were included. A propensity matched analysis was performed, adjusting the groups for the variables of Sarculator, to assess the effect of vascular resection on oncological outcomes.

RESULTS

Overall 425 patients were identified. Twenty-four (5%) patients had vascular resection. At final pathology 18 patients had vascular infiltration, 2 vascular encasement and 4 involvement without infiltration. Vascular resection was associated with longer operative time (480' vs. 330'; p < 0.001) and greater need for transfusions (4 vs. 0 units; p < 0.001), and was burdened by a higher rate of major complications (54% vs. 25%; p = 0.002). After propensity matched analysis, patients undergoing vascular resection had a lower 5-year OS (60% vs. 81%; p = 0.05), and a higher incidence of local and distant recurrence at 5 years (local: 45% vs. 24%, p = 0.05; distant: 20% vs. 0%, p = 0.04).

CONCLUSIONS

Vascular resection is feasible and safe even in the context of multivisceral resection for primary retroperitoneal liposarcomas, although associated to a higher complication rate. However, the independent association between vascular involvement and a higher risk of local recurrence, distant metastases and death may imply a more aggressive biology, which should be factored in the initial management of this complex disease.

A Comprehensive Review on Solitary Fibrous Tumor: New Insights for New Horizons

Simple Summary

Solitary fibrous tumor (SFT) is a malignant condition that exhibits different clinical behaviors ranging from low to high aggressive SFT, with dedifferentiated SFT (DD-SFT) being the fastest-growing subtype. Even when surgery alone provides curation rates above 60%, recurrences do occur in a fraction of patients where surgery is unable to provide disease control. Among the systemic therapeutic options, antiangiogenic compounds have shown higher efficacy than chemotherapy by indirect comparisons. Furthermore, rotating different antiangiogenics, at the progression time, has been shown to be effective. The exception is DD-SFT since it is resistant to antiangiogenics but can respond to chemotherapy. This comprehensive review also analyzes the underlying molecular components that play a key role in SFT origin and aggressiveness. The discovery in 2013 of anomalous fusion genes between NAB2 and STAT6 was determinant to increase the knowledge on the molecular drivers in SFT that could be potential targets for future therapies.

Abstract

Solitary fibrous tumor (SFT) is a rare mesenchymal, ubiquitous tumor, with an incidence of 1 new case/million people/year. In the 2020 WHO classification, risk stratification models were recommended as a better tool to determine prognosis in SFT, to the detriment of “typical” or “malignant” classic terms. The risk for metastasis is up to 35–45%, or even greater, in series with a longer follow-up. Over the last few decades, advances in immunohistochemistry and molecular diagnostics identified STAT6 nuclear protein expression and the NAB2–STAT6 fusion gene as more precise tools for SFT diagnosis. Recent evidence taken from retrospective series and from two prospective phase II clinical trials showed that antiangiogenics are active and their sequential use from first line should be considered, except for dedifferentiated SFT for which chemotherapy is the best option. Since the fusion transcript driver’s first description in 2013, new insights have been brought on key molecular events in SFT. This comprehensive review mainly focuses on the superior efficacy of antiangiogenics over chemotherapeutic agents in SFT, provides the current knowledge of key molecules that could co-drive the SFT behavior, and suggests new target candidates that deserve to be explored in preclinical and clinical research in SFT.

Management of Primary Retroperitoneal Sarcoma (RPS) in the Adult: An Updated Consensus Approach from the Transatlantic Australasian RPS Working Group

BACKGROUND

Retroperitoneal soft tissue sarcomas comprise a heterogeneous group of rare tumors of mesenchymal origin that include several well-defined histologic subtypes. In 2015, the Transatlantic Australasian RPS Working Group (TARPSWG) published consensus recommendations for the best management of primary retroperitoneal sarcoma (RPS). Since then, through international collaboration, new evidence and knowledge have been generated, creating the need for an updated consensus document.

METHODS

The primary aim of this study was to critically evaluate the current evidence and develop an up-to-date consensus document on the approach to these difficult tumors. The resulting document applies to primary RPS that is non-visceral in origin, with exclusion criteria as previously described. The relevant literature was evaluated and an international group of experts consulted to formulate consensus statements regarding the best management of primary RPS. A level of evidence and grade of recommendation were attributed to each new/updated recommendation.

RESULTS

Management of primary RPS was considered from diagnosis to follow-up. This rare and complex malignancy is best managed by an experienced multidisciplinary team in a specialized referral center. The best chance of cure is at the time of primary presentation, and an individualized management plan should be made based on the 29 consensus statements included in this article, which were agreed upon by all of the authors. Whenever possible, patients should be enrolled in prospective trials and studies.

CONCLUSIONS

Ongoing international collaboration is critical to expand upon current knowledge and further improve outcomes of patients with RPS. In addition, prospective data collection and participation in multi-institution trials are strongly encouraged.

Retroperitoneal Liposarcoma Presenting With Malignant Gastric Outlet Obstruction and Acute Pancreatitis: A Case Report

Dedifferentiated liposarcomas (DDLPS) are rare, high-grade malignancies that usually originate in the retroperitoneum. Frequently, they present as asymptomatic masses, abdominal distention, abdominal pain, and weight loss. They tend to grow significantly and are usually large in size at the time of diagnosis. Surgical resection is the mainstay of treatment; however, local recurrence is common. When unresectable, they can invade local structures and produce a significant mass effect on the adjacent organs. Here we present the first case of malignant gastric outlet obstruction (MGOO) and acute pancreatitis from a retroperitoneal DDLPS.

Primary mesenteric sarcomas: Collaborative experience from the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG)

BACKGROUND

Primary mesenteric soft tissue sarcomas (STS) are rare and limited evidence is available to inform management. Surgical resection is challenging due to the proximity of vital structures and a need to preserve enteric function.

OBJECTIVES

To determine the overall survival (OS) and recurrence-free survival (RFS) for patients undergoing primary resection for mesenteric STS.

METHODS

The Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) is an intercontinental collaborative comprising specialist sarcoma centers. Data were collected retrospectively for all patients with mesenteric STS undergoing primary resection between 2000 and 2019.

RESULTS

Fifty-six cases from 15 institutions were included. The spectrum of pathology was similar to the retroperitoneum, although of a higher grade. R0/R1 resection was achieved in 87%. Median OS was 56 months. OS was significantly shorter in higher-grade tumors (p = .018) and extensive resection (p < .001). No significant association between OS and resection margin or tumor size was detected. Rates of local recurrence (LR) and distant metastases (DM) at 5 years were 60% and 41%, respectively. Liver metastases were common (60%), reflecting portal drainage of the mesentery.

CONCLUSION

Primary mesenteric sarcoma is rare, with a modest survival rate. LR and DM are frequent events. Liver metastases are common, highlighting the need for surveillance imaging.

Innate inflammatory markers for predicting survival in retroperitoneal sarcoma

INTRODUCTION

Existing prognostic tools for retroperitoneal sarcomas (RPS) utilize parameters that can be accurately determined only postoperatively. This study evaluated the application of the neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) levels for predicting prognosis in primary RPS.

MATERIALS AND METHODS

We retrospectively analyzed our database of patients with primary RPS operated between 2008 and 2018. The NLR was calculated from preoperative blood tests and its association with outcomes was determined.

RESULTS

The NLR values of 78 suitable patients were analyzed. Patients were classified in the NLR-high group if the NLR was ≥2.1. High-grade tumors were more common in the NLR-high group (71.6% vs 48%, P = .02). NLR-high patients had impaired overall survival (OS) and progression-free survival (PFS) compared to NLR-low patients (median OS not reached vs 74 months 95% confidence interval [CI]: 21.6-126.4, P = .03; median PFS not reached vs 48 months 95% CI: 6.5-98.6, P = .06, respectively). Multivariate analysis showed statistical significance only for PFS but not for OS (hazard ratio [HR] = 4.1, P = .03; HR = 2.3, P = .3). Patients with low CRP levels had improved OS and PFS.

CONCLUSIONS

The NLR may serve as a preoperative, easily derived marker for prognosis in RPS. Serum biomarkers may prove useful in these large and spatially heterogeneous tumors.

Inoperable Primary Retroperitoneal Sarcomas: Clinical Characteristics and Reasons Against Resection at a Single Referral Institution

BACKGROUND

The outcome of patients with retroperitoneal sarcomas (RPS) depends mainly on tumor biology and completeness of surgical resection. However, some patients are deemed not resectable for various reasons. This study analyzed a series of primary RPS patients to describe rate and reasons of primary inoperability at a large referral center.

METHODS

All consecutive patients affected by primary localized RPS referred for surgical treatment at our institution between January 1, 2013 and December 31, 2017 were analyzed. Patients were split in two groups: those who underwent surgical resection with curative intent, and those who were not resected.

RESULTS

A total of 322 patients were available for the current analysis: 285 (88.5%) underwent resection with curative intent, and 37 (11.5%) did not. Twenty of 322 (6.2%) patients who did not undergo resection had a technically unresectable tumor, whereas the remaining 18 of 322 (5.6%) were not amenable to a major surgical procedure due to comorbidities/poor performance status. The dominant technical reason was involvement of the celiaco-mesenteric vessels. At a median follow-up from the diagnosis of 34 months, 24 of 37 (64.9%) nonoperated and 48 of 285 (16.8%) operated patients died. The corresponding 4-year overall survival were 10.3% and 83.4%, respectively (p < 0.001).

CONCLUSIONS

Roughly, 10% of patients who presented with localized primary RPS at a large referral institution were not resected. An attempt to standardize the definition of resectability for primary localized RPS should be made considering anatomic, biologic, and patient-related factors.

Improved Biopsy Accuracy in Retroperitoneal Dedifferentiated Liposarcoma

BACKGROUND

Biopsy sensitivity in retroperitoneal dedifferentiated liposarcoma (DDLPS) is variable. Patients with grade 3 DDLPS face a significant risk of metastatic disease and may potentially benefit from neoadjuvant therapy, making highly accurate pretherapy diagnosis essential. Our study aimed to establish whether diagnostic sensitivity could be improved by targeting solid areas of tumor on percutaneous biopsy.

METHODS

Between 2016 and 2019, data on patients with suspected primary retroperitoneal sarcoma who underwent a biopsy were collected, and diagnostic accuracy was calculated. These data were compared with our previously reported series from 2005 to 2016. For DDLPS tumors, comparisons were then made between biopsies that targeted the solid component and those that did not.

RESULTS

Data were available for 121 patients in the current series and 238 from the previous study. The proportion of biopsies returning a histological subtype concordant with postoperative pathology was 83% in the current series, marking a significant improvement over our previous study (67%, p = 0.001). For diagnosis of DDLPS, biopsy sensitivity improved from 40 to 74% (p < 0.001), with an increase from 13 to 50% (p = 0.006) where grade 3 DDLPS was treated as a separate disease. Within the current series, targeted biopsy yielded a sensitivity of 100% for identifying DDLPS, compared with 10% in nontargeted biopsy (p < 0.001).

CONCLUSION

Systematic targeting of solid areas of tumor within suspected retroperitoneal liposarcoma has improved sensitivity for detection of both DDLPS and grade 3 DDLPS on biopsy. This approach minimizes the risk of underdiagnosis of patients with DDLPS who could benefit from neoadjuvant chemotherapy.

Soft-tissue sarcoma in adults: An update on the current state of histiotype-specific management in an era of personalized medicine

Soft-tissue sarcomas (STS) are rare tumors that account for 1% of all adult malignancies, with over 100 different histologic subtypes occurring predominately in the trunk, extremity, and retroperitoneum. This low incidence is further complicated by their variable presentation, behavior, and long-term outcomes, which emphasize the importance of centralized care in specialized centers with a multidisciplinary team approach. In the last decade, there has been an effort to improve the quality of care for patients with STS based on anatomic site and histology, and multiple ongoing clinical trials are focusing on tailoring therapy to histologic subtype. This report summarizes the latest evidence guiding the histiotype-specific management of extremity/truncal and retroperitoneal STS with regard to surgery, radiation, and chemotherapy.

Advances in soft-tissue sarcoma - There are no mistakes, only lessons to learn!

Background:

In this decade the treatment of advanced sarcoma has seen many highs and lows in terms of successful trials and failed trials. This is possible due to great collaborations, newer therapies and histology focused trials.

Methods:

In ASCO 2019 many sarcoma trials were presented and we chose 3 challenging clinical trials that widen our perspective on soft tissue sarcoma. We have critically analyzed the data and have discussed the implications of these trials on current practice. First trial was ANNOUNCE trial which was done to confirm the efficacy of olaratumab after its dramatic success in advanced soft tissue sarcoma in a phase 2 trial. Another trial STRASS trial, which was unique because of being first successfully conducted randomized trial addressing preoperative radiotherapy in retroperitoneal soft tissue sarcoma. Third trial was phase 2 trial SARC 028 trial exploring the role of immunotherapy in pleomorphic undifferentiated sarcoma and liposarcoma subgroup.

Result:

ANNOUNCE trial failed to show OS benefit in olaratumab/doxorubicin arm as compared to doxorubicin/placebo arm. Based upon this FDA has revoked the approval of olaratumab leading to nihilism and disappointment amongst oncologists. In STRASS trial failed to meet the primary end point though there was a benefit in the liposarcoma subgroup in terms of abdominal recurrence free survival. There are several reasons that this trial might have failed. First, RPSs are not homogeneous population. RPSs might behave very differently as per the histopathology ranging from well differentiated LPS to leiomyosarcoma. Since the event rate in well-differentiated liposarcoma might happen late, the median follow-up of 43 months might not be sufficient. In SARC trial ORR in pleomorphic undifferentiated sarcoma (PUS) cohort was 9/40 (22.5%), while response rates in liposarcoma cohort were 4/39 (10.2%). There was poor correlation between the response and the tumor cells' PD-L1 positivity. Simultaneously, we must not take for granted the role of pembrolizumab in PUS as the previous study (PEMBROSARC) had also showed dismal outcomes with immunotherapy.

Conclusion:

In this paper we discuss the intricacies of these trials and how they affect the rapidly changing landscape in advanced soft tissue sarcoma.