Retroperitoneal sarcomas: patterns of care at diagnosis, prognostic factors and focus on main histological subtypes: a multicenter analysis of the French Sarcoma Group

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.

Standardizing Surgical Management of Retroperitoneal Sarcomas: Dawn of a New Surgical Subspeciality in India

BACKGROUND

Retroperitoneal sarcomas are a complex and heterogenous group of tumors. An approach to these tumors should be guided by a clear understanding of the disease biology and anatomical principles, which mandates a dedicated multidisciplinary team approach at all steps of management. We present our experience of evolution as a high-volume sarcoma center with a dedicated multidisciplinary tumor board (the RP clinic) with consequent standardization of surgeries and management protocols.

METHODS

A retrospective analysis of a prospectively maintained database for patients undergoing surgery from January 2011 to June 2023 was performed. Data were divided into the pre-clinic era (2011-2017) and post-clinic era (2018-2023). Survival curves were obtained using the Kaplan-Meier method, and the Chi-square test was used to test significance for categorical variables. Time trends were analyzed using the one-way analysis of variance (ANOVA) test. A p value ≤ 0.05 was considered significant.

RESULTS

Overall, 254 patients were operated during this period; 36.6% of patients underwent surgeries in the pre-RP clinic era (6 years) and 63.3% in the post-RP clinic era (4.5 years). There was a statistically significant increase in the number of cases being operated per year, from an average of 16.3 in the pre-clinic era to 42.4 in the post-RP clinic era (p = 0.001). The post-RP clinic era also showed a significant increase in compartment and multivisceral resections (49% vs. 18.2%; p = 0.0001).

CONCLUSIONS

Establishment of a dedicated multidisciplinary tumor board (RP clinic) resulted in standardization of management protocols, resulting in optimal oncological and surgical outcomes.

Impact of three-dimensional-printing technology guidance on surgical outcomes for retroperitoneal sarcoma: A propensity score-matched study

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.

PLAIN LANGUAGE SUMMARY

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.

Real-world experience of Doxorubicin Monotherapy for Advanced or Metastatic Retroperitoneal Sarcoma: A Single Institutional Study of 16 Cases

BACKGROUND/AIM

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.

PATIENTS AND 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.

CONCLUSION

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.

PEC-PRO: A new prognostic score from a series of 87 patients with localized perivascular epithelioid cell neoplasms (PEComas) treated with curative intent

BACKGROUND

Perivascular epithelioid cell neoplasms (PEComas) encompass a heterogeneous family of mesenchymal tumors. Previously described clinicopathologic features aimed at distinguishing benign from malignant variants but lacked prognostic value.

METHODS

This retrospective analysis examined clinicopathologic data from patients who had localized PEComa across French Sarcoma Network centers. The authors analyzed 12 clinicopathologic features in a Cox proportional hazard framework to derive a multivariate prognostic risk model for event-free survival (EFS). They built the PEComa prognostic score (PEC-PRO), in which scores ranged from 0 to 5, based on the coefficients of the multivariate model. Three groups were identified: low risk (score = 0), intermediate risk (score = 1), and high risk (score ≥ 2).

RESULTS

Analyzing 87 patients who had a median 46-month follow-up (interquartile range, 20-74 months), the median EFS was 96.5 months (95% confidence interval [CI], 47.1 months to not applicable), with 2-year and 5-year EFS rates of 64.7% and 58%, respectively. The median overall survival was unreached, with 2-year and 5-year overall survival rates of 82.3% and 69.3%, respectively. The simplified Folpe classification did not correlate with EFS. Multivariate analysis identified three factors affecting EFS: positive surgical margins (hazard ratio [HR], 5.17; 95% CI, 1.65-16.24; p = .008), necrosis (HR, 3.94; 95% CI, 1.16-13.43; p = .030), and male sex (HR, 3.13; 95% CI, 1.19-8.27; p = 0.023). Four variables were retained in the prognostic model. Patients with low-risk PEC-PRO scores had a 2-year EFS rate of 93.7% (95% CI, 83.8%-100.0%), those with intermediate-risk PEC-PRO scores had a 2-year EFS rate of 67.4% (95% CI, 53.9%-80.9%), and those with high-risk PEC-PRO scores had a 2-year EFS rate of 2.3% (95% CI, 0.0%-18.3%).

CONCLUSIONS

The PEC-PRO score reliably predicts the risk of postoperative recurrence in patients with localized PEComa. It has the potential to improve follow-up strategies but requires validation in a prospective trial.

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.

Intraoperative motive for incomplete resection in primary retroperitoneal sarcoma

INTRODUCTION

Surgical resection is the current standard of care for retroperitoneal sarcoma (RPS). Recent data suggests that up to 5% of patient have incomplete (R2) resection. The exact reason why patients scheduled for surgery with a curative intent to treat ended up with an R2 resection is largely unknown.

AIM OF THE STUDY

To identify intraoperative findings responsible for incomplete (R2) resection in primary RPS.

METHODS

All records of consecutive patients scheduled for a non-metastatic primary RPS surgery between 1995 and 2020 in a tertiary care sarcoma centre were retrospective analyzed.

RESULTS

Among the 347 patients scheduled for surgery, 13 (3.7%) had an incomplete (R2) resection. The reasons for incomplete surgery were intraoperative finding of vascular involvement of great vessels in 5 patients, previously undetected peritoneal metastases in 5 patients, invasion of contralateral kidney/ureter in 2 patients and the need to preserve both kidneys in 1 patient because of his past medical history. Among these patients, 3 had a laparotomy without resection and 10 had a partial resection (i.e. debulking surgery). Severe postoperative complications occurred in 5 patients. The median length of stay in hospital was 19days. After a median follow-up of 12months, the median survival of patients after incomplete resection was 18months. The 1-y, 5-y and 8-y overall survival (OS) for these patients were 46%, 14%, and 7%, respectively.

CONCLUSION

Incomplete (R2) resection for a primary RPS surgery is rare in specialized sarcoma center. The next steps should be to identify the preoperative criteria that lead to this accurate selection and to define the best practice in front of a peroperative discovery of an unresectable RPS.

LEVEL OF EVIDENCE

III.

Retroperitoneal Soft Tissue Sarcoma: Emerging Therapeutic Strategies

Retroperitoneal soft tissue sarcoma (RPS) is a rare and heterogenous disease for which surgery is the cornerstone of treatment. However, the local recurrence rate is much higher than in soft tissue sarcoma of the extremities since wide resection is usually unfeasible in RPS due to its large size, indistinct tumour borders, anatomical constraints and the thinness of the overlying peritoneum. Local recurrence is the leading cause of death for low-grade RPS, whereas high-grade tumours are prone to distant metastases. In recent decades, the role of emerging therapeutic strategies, such as more extended surgery and (neo)adjuvant treatments to improve oncological outcome in primary localised RPS, has been extensively investigated. In this review, the recent data on the evolving multidisciplinary management of primary localised RPS are comprehensively discussed. The heterogeneity of RPS, with their different histological subtypes and biological behaviour, renders a standard therapeutic 'one-size-fits-all' approach inappropriate, and treatment should be modified according to histological type and malignancy grade. There is sufficient evidence that frontline extended surgery with compartmental resection including all ipsilateral retroperitoneal fat and liberal en bloc resection of adjacent organs and structures, even if they are not macroscopically involved, increases local tumour control in low-grade sarcoma and liposarcoma, but not in leiomyosarcoma for which complete macroscopic resection seems sufficient. Additionally, preoperative radiotherapy is not indicated for all RPSs, but seems to be beneficial in well-differentiated liposarcoma and grade I/II dedifferentiated liposarcoma, and probably in solitary fibrous tumour. Whether neoadjuvant chemotherapy is of benefit in high-grade RPS remains unclear from retrospective data and is subject of the ongoing randomised STRASS 2 trial, from which the results are eagerly awaited. Personalised, histology-tailored multimodality treatment is promising and will likely further evolve as our understanding of the molecular and genetic characteristics within RPS improves.

The role of radiation therapy in the management of primary retroperitoneal sarcoma: A systematic review and clinical practice guidelines from the Australia and New Zealand Sarcoma Association

While surgery is the mainstay of treatment for localised retroperitoneal sarcoma, the use of radiotherapy (RT) remains controversial. This systematic review aimed to evaluate the role of RT for retroperitoneal sarcoma. A systematic review using the population, intervention, comparison, and outcome model from 1990 to 2022 identified 66 studies (a mixture of preoperative and postoperative RT); one randomised controlled trial (RCT) with two publications, 18 registry studies, and 46 retrospective studies. In the RCT of preoperative RT, there was no difference in local/abdominal recurrence. The pooled analysis of this RCT and a retrospective study showed a significant abdominal recurrence free survival benefit with preoperative RT in low grade liposarcoma. The RCT and the majority of retrospective series found RT did not improve recurrence free survival (11 of 16 no difference in combined local and distant RFS, 11 of 13 no difference in distant metastasis free survival), disease specific survival (9 of 12 studies) or overall survival (33 of 49 studies). The majority of studies found no association between RT and perioperative morbidity. In summary, preoperative RT may improve local control for low grade (well-differentiated or grades 1-2 dedifferentiated) liposarcoma, but not other histological subtypes. There is no strong evidence that perioperative RT provides an overall survival benefit. Patients with low grade retroperitoneal liposarcoma can be considered for preoperative RT to improve abdominal recurrence free survival. The rationale and level of evidence in this scenario should be carefully discussed by the multidisciplinary team with patients. RT should not be routinely recommended for other histological subtypes.

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.

Neoadjuvant Simultaneous Integrated Boost Radiation Therapy Improves Clinical Outcomes for Retroperitoneal Sarcoma

PURPOSE

Neoadjuvant radiation therapy (RT) with standard techniques (ST) offers a modest benefit in retroperitoneal sarcoma (RPS). As the high-risk region (HRR) at risk for a positive surgical margin and recurrence is posterior and away from radiosensitive organs at risk, using a simultaneous integrated boost (SIB) allows targeted dose escalation to the HRR while sparing these organs. We hypothesized that neoadjuvant SIB RT can improve disease control compared with ST, without increasing toxicity.

METHODS AND MATERIALS

We retrospectively identified patients with resectable nonmetastatic RPS from 2000 to 2021 who received neoadjuvant RT of 180 to 200 cGy/fraction to standard volumes. SIB patients received 205 to 230 cGy/fraction to the appropriate HRR. Clinical endpoints included abdominopelvic control (APC), recurrence-free survival (RFS), overall survival (OS), and acute toxicity.

RESULTS

With a median follow-up of 57 months (95% confidence interval [CI], 50-64), there were 103 patients with RPS who received either ST (n = 69) or SIB (n = 34) RT. Median standard volume dose was 5000 cGy (ST) and 4500 cGy (SIB), with a median HRR SIB dose of 5750 cGy. Liposarcomas (79% vs 53%; P = .004) and cT4 tumors (59% vs 19%; P < .001) were more common in the SIB cohort, without a significant difference in the rate of resection (82% vs 81%; P = .88) or R1 margin (53.5% vs 50%; P = .36); there were no R2 resections. SIB was associated with a significant improvement in 5-year APC (96% vs 70%; P = .046) and RFS (60.2% vs 36.3%; P = .036), with a nonsignificant OS difference (90.1% vs 67.5%; P = .164). On multivariable analysis, SIB remained a predictor for APC (hazard ratio, 0.07; 95% CI, 0.01-0.74; P = .027) and RFS (hazard ratio, 0.036; 95% CI, 0.13-0.98; P = .045). SIB showed no significant detriment in toxicity, albeit with a lower rate of overall grade 3 acute toxicity (3% vs 22%; P = .023) compared with ST.

CONCLUSIONS

In RPS, dose escalation with neoadjuvant SIB RT may be independently associated with improved APC and RFS, without a detriment in toxicity, compared with ST. With the addition of standard RT having only a modest benefit compared with surgery alone, our study suggests that future prospective studies evaluating for the benefit of SIB RT should be considered.

Surgery at specialised sarcoma centres improves patient outcomes - A systematic review by the Australia and New Zealand sarcoma association clinical practice guidelines working party

BACKGROUND

Optimal management of sarcoma requires multidisciplinary team input throughout the process of diagnosis, treatment and follow up. This systematic review aimed to evaluate the impact of surgery performed at specialised sarcoma centres on outcomes.

METHODS

A systematic review was conducted using the population, intervention, comparison and outcome (PICO) model. Medline, Embase, Cochrane Central databases were queried for publications that evaluated the local control, limb salvage rate, 30-day and 90-day surgical mortality, and overall survival in patients undergoing surgery in a specialist sarcoma centre compared with non-specialist centre. Each study was screened by two independent reviewers for suitability. A qualitative synthesis of the results was performed.

RESULTS

Sixty-six studies were identified. The majority of studies were Level III-3 as assessed by the NHMRC Evidence Hierarchy, whilst just over half of the studies were of good quality. Definitive surgery performed at specialised sarcoma centres was associated with improved local control as defined by lower rate of local relapse, higher rate of negative surgical margins, improved local recurrence free survival and higher limb conservation rate. Available evidences show a favourable pattern of lower 30-day and 90-day mortality rates, and greater overall survival when surgery was performed in specialist sarcoma centres compared with non-specialised centres.

CONCLUSIONS

Evidences support better oncological outcomes when surgery is performed at specialised sarcoma centre. Patients with suspected sarcoma should be referred early to a specialised sarcoma centre for multidisciplinary management, which includes planned biopsy and definitive surgery.

A century of retroperitoneal soft-tissue sarcoma research: From single center experience to precision oncology? A bibliometric analysis of past, present, and future perspectives

BACKGROUND

Increasing publication numbers in the biomedical field led to an improvement of patient care in many aspects but are challenging for scientists when integratively processing data of their fields. Using bibliometric analyses, the present study assesses the productivity and predominant topics in retroperitoneal soft-tissue sarcoma (RPS) research across the past 122 years, thereby identifying crucial questions to address in future RPS research.

METHODS

Using the Web of Science Core Collection, 1018 RPS-associated publications from 1900 to 2022 were identified and analyzed regarding key bibliometric variables using the Bibliometrix R package and the VOSviewer software.

RESULTS

A continuous increase in RPS-associated publication numbers can be noticed over the time, which is strongly pronounced from 2005 onwards, and is characterized by a multinationally driven collaborative clinical research focus. The research primarily reflects progression regarding surgical techniques, histology-based therapy, radiotherapy regimens, and identification of prognostic clinicopathological factors. This progression is accompanied with improved overall survival of RPS patients. However, a paucity of RPS-specific basic/translational research indicates that such research might be additionally needed to better understand the pathophysiology of RPS and with that to enable the development of personalized therapies and to further improve patient outcome.

CONCLUSION

Increasing publication numbers of multinationally driven clinical RPS research are accompanied with improved overall survival of RPS patients, highlighting the importance of international collaborations to facilitate future clinical trials. However, this bibliometric analysis reveals a lack of RPS-specific basic/translational research which is needed to further improve patient outcome in the context of precision oncology.

Primary retroperitoneal sarcoma: A comparison of survival outcomes in specialist and non-specialist sarcoma centres

BACKGROUND

Consensus guidelines outline that patients with primary retroperitoneal sarcoma (RPS) should be managed within specialist sarcoma centres (SSC). There is, however, a paucity of population-based data detailing incidence and outcomes in these patients. Hence, we aimed to evaluate patterns of care among RPS patients in England and compare outcomes for those undergoing surgery in high-volume specialist sarcoma centres (HV-SSC), low-volume SSC (LV-SSC), and non-SSC (N-SSC).

METHODS

Data on patients diagnosed with primary RPS between 2013 and 2018 were extracted from NHS Digital's National Cancer Registration and Analysis Service using the national cancer registration dataset. Diagnostic pathways, treatment, and survival outcomes were compared between HV-SSC, LV-SSC, and N-SSC. Uni- and multivariate analyses were calculated.

RESULTS

Of 1878 patients diagnosed with RPS, 1120 (60%) underwent surgery within 12 months of diagnosis, with 847 (76%) operated on at SSC; of these, 432 patients (51%) were operated on in HV-SSC, and 415 (49%) in LV-SSC. One- and 5-year estimated overall survival (OS) rates for patients undergoing surgery in N-SSC were 70.6% (95% confidence interval [CI]: 64.8-75.7) and 42.0% (CI: 35.9-47.9), compared to 85.0% (CI: 81.1-88.1) and 51.7% (CI: 46.6-56.6) in LV-SSC (p < 0.01), and 87.4% (CI: 83.9-90.2) and 62.8% (CI: 57.9-67.4) in HV-SSC, (p < 0.01). After adjusting for patient- and treatment-related factors, patients treated in HV-SSC were found to have significantly longer OS than those treated at LV-SSC, with an adjusted hazard ratio of 0.78 (CI: 0.62-0.96, p < 0.05).

CONCLUSION

Patients with RPS undergoing surgery in HV-SSC have significantly better survival outcomes than those treated in N-SSC and L-SSC.

Deciding individual treatment for primary retroperitoneal sarcoma

INTRODUCTION

Retroperitoneal sarcomas (RPS) are rare mesenchymal tumors that account for only 0.1-0.2% of all malignancies. Management of this disease is challenging, and resection remains the cornerstone of treatment. Ongoing international collaboration has expanded our knowledge of this disease, allowing for a more personalized approach to RPS patients resulting in improved survival over time. Due to the heterogeneity of RPS, with differing recurrence patterns and sensitivities to neoadjuvant therapies based on histology and grade, management of RPS should be tailored to the individual patient.

AREAS COVERED

Our review focuses on a histology-driven approach in the management of primary RPS. We searched relevant articles from 1993 to 2023 that investigated prognostic factors and treatment of patients with RPS and summarized recent advances and future directions in the field.

EXPERT OPINION

Deeper understanding of the role of neoadjuvant radiotherapy and ongoing trials investigating the role of neoadjuvant chemotherapy will potentially contribute to the development of individualized treatment pathways.

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.

Prognostic factors and outcomes of adult spermatic cord sarcoma. A study from the French Sarcoma Group

PURPOSE

To evaluate the outcomes of adult patients with spermatic cord sarcoma (SCS).

METHODS

All consecutive patients with SCS managed by the French Sarcoma Group from 1980 to 2017 were analysed retrospectively. Multivariate analysis (MVA) was used to identify independent correlates of overall survival (OS), metastasis-free survival (MFS), and local relapse-free survival (LRFS).

RESULTS

A total of 224 patients were recorded. The median age was 65.1 years. Forty-one (20.1%) SCSs were discovered unexpectedly during inguinal hernia surgery. The most common subtypes were liposarcoma (LPS) (73%) and leiomyosarcoma (LMS) (12.5%). The initial treatment was surgery for 218 (97.3%) patients. Forty-two patients (18.8%) received radiotherapy, 17 patients (7.6%) received chemotherapy. The median follow-up was 5.1 years. The median OS was 13.9 years. In MVA, OS decreased significantly with histology (HR, well-differentiated LPS versus others = 0.096; p = 0.0224), high grade (HR, 3 versus 1-2 = 2.7; p = 0.0111), previous cancer and metastasis at diagnosis (HR = 6.8; p = 0.0006). The five-year MFS was 85.9% [95% CI: 79.3-90.6]. In MVA, significant factors associated with MFS were LMS subtype (HR = 4.517; p < 10-4) and grade 3 (HR = 3.664; p < 10-3). The five-year LRFS survival rate was 67.9% [95% CI: 59.6-74.9]. In MVA, significant factors associated with local relapse were margins and wide reresection (WRR) after incomplete resection. OS was not significantly different between patients with initial R0/R1 resection and R2 patients who underwent WRR.

CONCLUSIONS

Unplanned surgery affected 20.1% of SCSs. A nonreducible painless inguinal lump should suggest a sarcoma. WRR with R0 resection achieved similar OS to patients with correct surgery upfront.

The role of standard and novel radiotherapy approaches in management of retroperitoneal sarcomas

Primary non-metastatic retroperitoneal soft tissue sarcoma patients can be cured by radical surgery. However there remains a risk for patients to develop a local recurrence. To minimize this risk, patients with low grade liposarcomas might benefit from preoperative radiotherapy. This review summarizes all issues that should be considered for the irradiation of patients with retroperitoneal soft tissue sarcoma.

How to treat liposarcomas located in retroperitoneum

Almost half of retroperitoneal (RP) sarcomas are liposarcomas (LPS). The large majority of RP LPS are either well-differentiated LPS (WDLPS) or dedifferentiated LPS (DDLPS), these latter further classified according to grading in G2 and G3 DDLPS. Surgery is the only potentially curative treatment to achieve local control and possibly cure in primary localized disease. Over the last decade, a better delineation of the different histology-specific patterns of failure and the development of nomograms predictors of outcome has led to a better management of these rare tumors, with a special focus on non-surgical treatments. Available evidences - although far from exhaustive - show that radiation therapy might have a role, if any, as neoadjuvant treatment in locally aggressive histologies (i.e. WDLPS and G2 DDLPS), while it does not seem beneficial for histologies with a higher metastatic risk (i.e. G3 DDLPS and leiomyosarcoma). Neoadjuvant chemotherapy, instead, can be considered to reduce the risk of distant metastasis while waiting for the results of an ongoing RCT (STRASS-2) evaluating its effect in these tumors. However, given the rarity of these diseases and the subsequent lack of strong evidences to guide treatment, outcome improvement in these patients remains a challenge. Patients' referral to a sarcoma center where a dedicated specialized multidisciplinary team tailor optimal treatment on a case-by-case basis is crucial to ensure these patients the best outcome. Refining available nomograms - e.g including molecular variables - and identifying predictors of response/toxicity to chemotherapy and immunotherapy might be significantly helpful in tailoring treatments to the patient's characteristics. Also, new systemic agents are eagerly awaited for improving the management further.

Surgical Management of Retroperitoneal Sarcoma

Surgery is the cornerstone of treatment for retroperitoneal sarcoma (RPS). Surgery should be performed by a surgical oncologist with sub-specialization in this disease and in the context of a multidisciplinary team of sarcoma specialists. For primary RPS, the goal of surgery is to achieve the complete en bloc resection of the tumor along with involved organs and structures to maximize the clearance of the disease. The extent of resection also needs to consider the risk of complications. Unfortunately, the overarching challenge in primary RPS treatment is that even with optimal surgery, tumor recurrence occurs frequently. The pattern of recurrence after surgery (e.g., local versus distant) is strongly associated with the specific histologic type of RPS. Radiation and systemic therapy may improve outcomes in RPS and there is emerging data studying the benefit of non-surgical treatments in primary disease. Topics in need of further investigation include criteria for unresectability and management of locally recurrent disease. Moving forward, global collaboration among RPS specialists will be key for continuing to advance our understanding of this disease and find more effective treatments.

Multivisceral resection of primary multifocal retroperitoneal sarcomas: a retrospective study from a high-volume sarcoma center

Background

Although surgery plays a key role in the treatment of the primary retroperitoneal sarcoma (RPS), there remain few reports on the primary multifocal RPS.

Aims

This study aimed to identify the prognostic factors for the primary multifocal RPS in an effort to optimize the clinical management of this malignancy.

Methods

A retrospective analysis was conducted on a cohort of 319 primary RPS patients who underwent radical resection from 2009 to 2021, with post-operative recurrence as the primary endpoint of this study. COX regression was performed to identify the risk factors for post-operative recurrence, and a comparison was made to baseline and prognostic differences between multivisceral resection (MVR) and non-MVR groups with multifocal disease.

Results

There were 31 (9.7%) patients with multifocal disease, the mean tumor burden placed on them was 24.1 ± 11.9 cm, and nearly half of the patients (48.4%) had MVR. Dedifferentiated liposarcoma, well-differentiated liposarcoma, and leiomyosarcoma accounted for 38.7%, 32.3%, and 16.1%, respectively. The 5-year recurrence-free survival rate reached 31.2% (95% CI, 11.2-51.2%) in the multifocal group and 51.8% (95% CI, 44.2-59.4%) in the unifocal group (P = 0.010). Age (heart rate [HR] = 0.916; P = 0.039) and complete resection (HR = 1.861; P = 0.043) were identified as the independent risk factors for the post-operative recurrence of multifocal primary RPS.

Conclusions

Regarding primary multifocal RPS, the overall treatment strategy can be adopted for the treatment of the primary RPS, and MVR remains effective in boosting the chance of disease control for a selected group of patients.

Relevance for Patients

This study is relevant to patients as it highlights the importance of receiving appropriate treatment for the primary RPS, especially for those with multifocal disease. The treatment options should be evaluated carefully to ensure that the patients receive the most effective treatment for their specific type and stage of RPS. The potential risk factors for post-operative recurrence should be well understood to minimize those risks. Ultimately, this study underscores the importance of ongoing research to optimize the clinical management of RPS and improve outcomes for patients.

Complex Vascular Resections for Retroperitoneal Soft Tissue Sarcoma

Retroperitoneal sarcomas (RPSs) are locally aggressive tumors that can compromise major vessels of the retroperitoneum including the inferior vena cava, aorta, or main tributary vessels. Vascular involvement can be secondary to the tumor's infiltrating growth pattern or primary vascular origin. Surgery is still the mainstay for curing this disease, and resection of RPSs may include major vascular resections to secure adequate oncologic results. Our improved knowledge in the tumor biology of RPSs, in conjunction with the growing surgical expertise in both sarcoma and vascular surgical techniques, has allowed for major vascular reconstructions within multi-visceral resections for RPSs with good perioperative results. This complex surgical approach may include the combined work of various surgical subspecialties.

A Retroperitoneal Calcified Mass: Synovial Sarcoma

Retroperitoneal synovial sarcoma is an extremely rare and aggressive tumor. Although it does not have a typical radiological appearance, it can sometimes appear as a calcified mass. The most important step in the treatment of synovial sarcoma is complete resection. However, despite complete resection, local recurrence and systemic spread rates remain high, and chemo/radiotherapy may be considered in high-risk patients.

Management of Recurrent Retroperitoneal Sarcoma

Recurrence after resection of retroperitoneal sarcoma is common and varies by histological subtype. Pattern of recurrence is similarly affected by histology (e.g., well-differentiated liposarcoma is more likely to recur locoregionally, whereas leiomyosarcoma is more likely to develop distant metastases). Radiotherapy may provide effective locoregional control in limited circumstances and the data on the impact of chemotherapy are scant. Surgery for locally recurrent disease is associated with the greatest survival benefit; however, data are retrospective and from a highly selected subgroup of patients. Limited retrospective data have also suggested a survival association with the resection of limited distant metastases. Given the complexity of these patients, multidisciplinary evaluation at a high-volume sarcoma center is critical.

Treatment Pathways and Prognosis in Advanced Sarcoma with Peritoneal Sarcomatosis

Sarcomas represent a heterogeneous group of mesenchymal malignancies that most commonly occur in the extremities, retroperitoneum, and head and neck. Intra-abdominal manifestations are rare and prove particularly difficult to treat when peritoneal sarcomatosis is present. Because of the overall poor prognosis of the disease, a tailored approach to surgical management is essential to achieve satisfactory outcomes with limited morbidity. We present the perioperative and long-term outcomes of 19 cases of sarcoma with peritoneal sarcomatosis treated surgically at our hospital. Treatment pathways were reviewed and clinical follow-up was performed. Patient characteristics, medical history, tumor subtype, surgical approach, hospital stay, complications, follow-up, and overall survival (OS) were assessed. Our patients were 9 women and 10 men with a median age of 45.9 years (18-88) and a median survival of 30 months (0-200). In most cases, peritoneal sarcomatosis was either discovered during surgery or the procedure was performed with palliative intent from the beginning. The surgical approach in these cases is very heterogeneous and should consider a variety of factors to tailor an approach for each patient. Sharing our experiences will help to increase knowledge about this rare disease and provide insight into the management of future cases.

Re-excision After Unplanned Excision of Soft Tissue Sarcoma is Associated with High Morbidity and Limited Pathologic Identification of Residual Disease

BACKGROUND

Patients with unplanned excision (UPE) of trunk and extremity soft tissue sarcoma (STS) present a significant management challenge for sarcoma specialists. Oncologic re-resection has been considered standard practice after UPE with positive or uncertain margins. A strategy of active surveillance or "watch and wait" has been suggested as a safe alternative to routine re-excision. In this context, the current study sought to evaluate short-term outcomes and morbidity after re-resection to better understand the risks and benefits of this treatment strategy.

METHODS

A retrospective, single-institution study reviewed patients undergoing oncologic re-resection after UPE of an STS during a 5-year period (2015-2020), excluding those with evidence of gross residual disease. Short-term clinical outcomes were evaluated together with final pathologic findings.

RESULTS

The review identified 67 patients undergoing re-resection after UPE of an STS. Of these 67 patients, 45 (67%) were treated with a combination of external beam radiation therapy (EBRT) and surgery. Plastic surgery was involved for reconstruction in 49 cases (73%). The rate of wound complications after re-resection was 45 % (n = 30), with 15 % (n = 10) of the patients experiencing a major wound complication. Radiation therapy and plastic surgery involvement were independently associated with wound complications. Notably, 45 patients (67%) had no evidence of residual disease in the re-resection specimen, whereas 13 patients (19 %) had microscopic disease, and 9 patients (13%) had indeterminate pathology.

CONCLUSION

Given the morbidity of re-resection and limited identification of residual disease, treatment plans and discussions with patients should outline the expected pathologic findings and morbidity of surgery.

Retroperitoneal Sarcomas: a Current Review on Management

Retroperitoneal sarcomas are heterogeneous tumours with variable disease biology and outcomes. The prognosis is primarily related to tumour histology and grade as well as the ability to achieve margin negative resection. Surgery involves compartment or contiguous organ resection to achieve the above goal. Careful utilization of neoadjuvant and adjuvant strategies like radiotherapy and/or chemotherapy can lead to improvement in margin status, thereby contributing to better local control and possibly reducing systemic dissemination. Use of targeted therapies has paved newer pathways of treatment integration centred on molecular and genetic targets. The aim of this review is to update the reader on all aspects of retroperitoneal sarcoma management including emphasis on pertinent and landmark trials in this regard.

Treatment algorithm and surgical outcome for primary and recurrent retroperitoneal sarcomas: A long-term single-center experience of 242 cases

BACKGROUND AND OBJECTIVES

Retroperitoneal sarcomas (RPSs) are difficult to manage, rare malignant tumors. This single-center, retrospective study aimed to analyze the treatment algorithm and outcomes of aggressive surgical treatment in patients with primary and recurrent RPS.

METHODS

Data of 242 consecutive patients with RPS who underwent surgical treatment at the Peking University Cancer Hospital Sarcoma Center between January 2010 and February 2021 were collected and analyzed. Indications for surgery were based on the treatment algorithm.

RESULTS

A total of 145 patients with primary RPS and 97 with recurrent RPS were included. The recurrent cohort comprised more patients with multifocal tumors than the primary cohort (64.9% vs. 15.2%). R0/R1 resection was achieved in 94.5% and 81.4% of the primary and recurrent RPS cases, respectively. Major complication rates in the primary and recurrent cohorts were 17.9% and 30.9%, respectively. During a median follow-up of 51 months, the estimated 5-year overall survival, local recurrence, and distant metastasis rates for patients with primary and recurrent RPS were 61.0% versus 37.1%, 47.4% versus 71.3%, and 18.4% versus 17.6%, respectively.

CONCLUSIONS

Aggressive surgical treatment achieved good local control and long-term survival in patients with primary RPS, whereas the prognosis in patients with recurrence were significantly worse.

Retroperitoneal and Mesenteric Liposarcomas

Retroperitoneal liposarcomas are a rare entity and are comprised mostly of the well-differentiated and dedifferentiated subtypes. Eight-year survival ranges from 30% to 80% depending on histologic subtype and grade. Surgery is the cornerstone of treatment and compartment resection is the current standard. Mesenteric liposarcomas are extremely rare and comprise more high-grade lesions, with poorer prognosis of 50% 5-year overall survival. They are managed with a similar aggressive surgical approach. This review presents the current management of retroperitoneal and mesenteric liposarcomas.

Surgical management of primary undifferentiated pleomorphic sarcoma of the rectum: a case report and review of the literature

Background

Undifferentiated pleomorphic sarcoma (UPS) is a malignant soft tissue tumor that has been reclassified from malignant fibrous histiocytoma with the development of the pathological diagnosis. It principally occurs in the extremities but rarely occurs in the rectum. We herein report a rare case of UPS arising in the rectum.

Case presentation

A 85-year-old woman was referred to our hospital with a complaint of anal pain, which had persisted for several months. Computed tomography (CT) showed a 53 × 58 × 75 mm mass on the left side of the rectum. Colonoscopy revealed a submucosal elevation in the rectum without any exposure of the tumor to the surface. Contrast-enhanced CT and magnetic resonance imaging revealed an 80-mm mass that originated in the rectal muscular propria, and we suspected a gastrointestinal stromal tumor. No lymph node metastasis or distant metastasis was observed. We performed a laparoscopic Hartmann’s operation. Intraoperatively, severe adhesion around the tumor caused tumor injury and right ureteral dissection. Thus, laparoscopic right ureteral anastomosis and ureteral stenting were additionally performed. The operation time was 6 h and 3 min, and the estimated blood loss was small. The patient was discharged without complications 25 days after surgery. A pathological examination showed that the tumor was composed of highly heterogeneous cells with no specific differentiation traits, leading to a diagnosis of UPS. Contrast-enhanced CT performed 2 months after surgery showed bilateral pelvic lymph node enlargement, which indicated recurrence. Considering the patient’s age, we performed radiotherapy (50 Gy/25 Fr targeting the pelvic region). At present, 16 months have passed since the completion of radiotherapy. Contrast-enhanced CT shows that the recurrent lymph nodes have disappeared, and no new distant metastasis has been observed.

Conclusions

We reported a case of UPS arising in the rectum. The surgical procedure and indication of preoperative therapy should be carefully selected because complete removal of the tumor is desirable in UPS.

Overall survival in abdominal wall sarcoma treated with curative intent surgery: A retrospective study from two European referral centres

INTRODUCTION

Primary abdominal wall sarcomas are rare, heterogeneous tumours. The mainstay of management is surgery, although local recurrences (LR) and distant metastases (DM) are common.

OBJECTIVES

Overall survival (OS) and disease-free survival (DFS) were primary outcomes; factors associated with prognosis secondary outcomes.

MATERIALS AND METHODS

Patients undergoing surgery of primary abdominal wall sarcomas between April 2008 and May 2018 were identified at two referrals centres for sarcoma surgery. Patient demographics, tumour and treatment-related characteristics were recorded and analysed.

RESULTS

A cohort of 65 patients underwent surgical resection with a median follow-up of 56 months, 5-year OS and DFS were 69% and 71%, respectively. Eleven patients (16.9%) experienced a recurrence event: 6 LR (9.2%), 10 DM (15.4%) and 5 both (7.7%). At univariate analysis, size (p = 0.03), grade (p = 0.001) and depth (p = 0.04) were associated with OS while size (p = 0.02) was associated with DFS. No significant relationship with tumour depth, type of surgery, surgical margin status or neo-/adjuvant treatment was demonstrated.

CONCLUSION

Recurrence events are less common following treatment of abdominal wall sarcomas if compared to extremities STSs, but size (≥5 cm), high malignancy grade (FNCLCC 3) and depth are associated with worse OS.

Synovial sarcoma of the popliteal fossa

Soft tissue sarcomas are heterogeneous group of neoplasms making up to 1% of all malignant tumors in the adult population. The tumor generally appears on the extremities near large joints of middle-aged patients, especially in the popliteal fossa. Our patient presented in February 2014 due to a slowly enlarging, darker-colored swelling in the left popliteal fossa. Upon physical examination, a somewhat nodular, immobile, tender subcutaneous mass was observed. There was no locoregional lymphadenopathy. Patohistological findings showed a high-grade primary malignant mesenchymal tumor, biphasic synovial sarcoma type. The patient underwent surgery with wide surgical excision, followed by radiotherapy treatment. Magnetic resonance imagining follow up after one year revealed tumor recurrence. Neurovascular bundle involvement was detected, but without adjacent bone and muscular invasion and above-the-knee partial amputation of the left leg was performed. The intervention resulted in a remission of the neoplastic process and the patient was scheduled for regular check-ups. Broad surgical resection of the tumor with negative margins was the primary treatment in this case. Mutilating operations are necessary when anatomical structures around the tumor do not allow complete reintervention.

Postoperative Outcomes of Distal Pancreatectomy for Retroperitoneal Sarcoma Abutting the Pancreas in the Left Upper Quadrant

Background

En bloc resection of the tumor with adjacent organs is recommended for localized retroperitoneal sarcoma (RPS). However, resection of the pancreas is controversial because it may cause serious complications, such as pancreatic fistula or bleeding. Thus, we evaluated the outcomes of distal pancreatectomy (DP) in pancreas-abutting RPS of the left upper quadrant (LUQ).

Methods

We retrospectively reviewed all consecutive patients who underwent surgery for RPS between September 2001 and April 2020. We selected 150 patients with all or part of their tumor located in the LUQ on preoperative computed tomography. Eighty-six patients who had tumors abutting the pancreas were finally enrolled in our study.

Results

Fifty-three patients (53/86; 61.6%) were included in the non-DP group, and 33 patients (33/86; 38.4%) were included in the DP group. Total postoperative complications and complication rates for those Clavien–Dindo grade 3 or higher were similar between the non-DP group and DP group (p = 0.290 and p = 0.550). In the DP group, grade B pancreatic fistulae occurred in 18.2% (6/33) of patients, but grade C pancreatic fistulae were absent, and microscopic pancreatic invasion was noted in 42.4% (14/33) of patients. During multivariate analysis, microscopic pancreatic invasion was deemed a risk factor for local recurrence (p = 0.029). However, there were no significant differences on preoperative computed tomography findings between the pancreatic invasion and non-invasion groups.

Conclusion

DP is a reasonable procedure for pancreas-abutting RPS located at the LUQ when both complications and complete resection are considered.

Macroscopically complete excision is a beneficial strategy for selected patients with peritoneal sarcomatosis

The occurrence of peritoneal sarcomatosis (PS) in patients with retroperitoneal sarcoma (RPS) indicates a poor prognosis. However, the appropriate treatment modality remains unclear. This study aimed to identify its prognostic factors and further explore the role of macroscopically complete excision (CE) in the management of PS. A retrospective database was established to evaluate patients with RPS who underwent resection between January 2011 and January 2019. Univariate and multivariate survival analyses were performed to analyze the prognostic factors and identify the population that will optimally benefit from CE. This study included a total of 49 patients with PS from 211 patients with RPS, and 34 (69.4%) patients of whom with PS underwent CE successfully. The median follow-up time was 36.0 months. There were 8 patients excluded because of loss to follow-up (n = 4) or death from complications within 90 days postoperatively (n = 4). The CE group had a marginally better prognosis compared to the macroscopically incomplete excision (IE) group (median disease-specific survival: 20 months vs. 8 months). Multivariate survival analysis demonstrated that completeness of operation (CE vs. IE) was the only independent prognostic factor in PS patients (P = 0.042). There was no significant difference in the overall complications between the CE and IE groups (P = 0.205). In conclusion, completeness of macroscopical excision is an independent prognostic predictor of PS. If technically possible, CE is a feasible strategy to improve the prognosis of selected patients with PS.

Adjuvant therapy for retroperitoneal sarcoma: a meta-analysis

Background

Adjuvant therapy is a promising treatment to improve the prognosis of cancer patients, however, the evidence base driving recommendations for adjuvant radiotherapy (ART) or chemotherapy (ACT) in retroperitoneal sarcomas (RPS) primarily hinges on observational data. The aim of this study was to evaluate the effectiveness of adjuvant therapy in the management of RPS patients.

Methods

We searched PubMed, Web of Science, Embase, ASCO Abstracts, and Cochrane Library for comparative studies (until December 2020) of adjuvant therapy versus surgery alone. Data on the following endpoints were evaluated: overall survival (OS), local recurrence (LR), recurrence-free survival (RFS), and metastasis-free survival (MFS). Data were summarized as hazard ratios (HR) with 95% confidence intervals (CI). Risk of bias of studies was assessed with Begg’s and Egger’s tests.

Results

A total of 15 trials were eligible, including 9281 adjuvant therapy and 21,583 surgery alone cases (20 studies for OS, six studies for RFS, two studies for LR, and two studies for MFS). Meta-analysis showed that ART was associated with distinct advantages as compared to surgery alone, including a longer OS (HR = 0.80, P < 0.0001), a longer RFS (HR = 0.61, P = 0.0002), and a lower LR (HR = 0.31, P = 0.005). However, this meta-analysis failed to demonstrate a benefit of ACT for RPS patients, including OS (HR = 1.11, P = 0.19), RFS (HR = 1.30, P = 0.09) and MFS (HR = 0.69, P = 0.09). In the sensitivity analysis, ACT was associated with a worse OS (HR = 1.19, P = 0.0002). No evidence of publication bias was observed.

Conclusions

Overall, the quality of the evidence was moderate for most outcomes. The evidence supports that ART achieved a generally better outcome as compared to surgery alone.

Supplementary information

The online version contains supplementary material available at 10.1186/s13014-021-01774-w.

[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.

[Retroperitoneal soft tissue sarcoma: role of radiotherapy]

BACKGROUND

Retroperitoneal soft tissue sarcomas (RPS) include tumors of mesenchymal origin with overall well-defined histological subtypes and heterogenic prognosis. For the first time with the publication of the STRASS study, which investigated the value of neoadjuvant radiotherapy in primary RPS, there is phase III evidence for the use of radiotherapy.

OBJECTIVE

The primary objective of the present article is to present the role of neoadjuvant radiotherapy in RPS since the publication of the STRASS study.

MATERIAL AND METHODS

We performed a non-systematic literature search. The results of retrospective and observational studies were compared to those of the STRASS study.

RESULTS

In the two of the largest analyses, the surveillance, epidemiology, and end results program (SEER) and the American National Cancer Database (NCDB), an improvement in overall survival due to radiotherapy in RPS could be shown. In contrast to these results, there was no significant improvement in 3‑year abdominal recurrence-free survival in the STRASS study. There was solely a trend to improved abdominal recurrence-free survival in initially unplanned subgroup analyses for patients with liposarcoma as well as low-grade sarcoma but not for leiomyosarcoma or high-grade sarcoma.

CONCLUSION

Thanks to international collaboration an academic randomized trial was even feasible in such a rare disease as RPS. The results of the STRASS study have relativized the potential benefit of radiotherapy in RPS. A longer follow-up especially regarding the role of radiotherapy in liposarcomas is desirable.

Prognostic implications of histological organ involvement in retroperitoneal sarcoma

BACKGROUND

The prognostic significance of histological organ involvement by retroperitoneal sarcoma subtype is unknown. The present study aimed to describe organ involvement across the subtypes, and the implications for survival.

METHODS

Patients undergoing surgery for primary retroperitoneal sarcoma at the Queen Elizabeth Hospital, Birmingham from April 2005 to September 2018 were identified retrospectively. Histological organ involvement was classed as pushing, infiltrative or neither. Univariable and multivariable Cox regression models were produced to analyse the association between histological organ involvement and both overall (OS) and recurrence-free (RFS) survival for the cohort as a whole, and by histological subtype.

RESULTS

Data were available for a total of 197 patients, of whom 171 (86.8 per cent) had at least one organ resected. Infiltrative organ behaviour was seen in 37 patients (18.8 per cent), and pushing behaviour in 67 (34.0 per cent). For the cohort as a whole, infiltration (hazard ratio (HR) 4.32, 95 per cent c.i. 2.35 to 7.93; P < 0.001), but not pushing (HR 1.62, 0.90 to 2.92; P = 0.106), was associated with significantly shorter OS, in comparisons with a group with neither of these behaviours. However, this effect was found to differ significantly by histological subtype (P = 0.009). For patients with dedifferentiated liposarcoma, there was no significant association between tumour behaviour and either OS (P = 0.508) or RFS (P = 0.313). However, in leiomyosarcoma, infiltrative behaviour was associated with shorter OS (P = 0.002), and both infiltrative (P < 0.001) and pushing (P = 0.010) behaviours were associated with shorter RFS, compared with tumours with neither behaviour. Multivariable analyses of both OS and RFS returned similar results.

CONCLUSION

The prognostic implications of organ involvement in retroperitoneal sarcoma vary by histological subtype.

Deep learning radiomic nomogram to predict recurrence in soft tissue sarcoma: a multi-institutional study

OBJECTIVES

To evaluate the performance of a deep learning radiomic nomogram (DLRN) model at predicting tumor relapse in patients with soft tissue sarcomas (STS) who underwent surgical resection.

METHODS

In total, 282 patients who underwent MRI and resection for STS at three independent centers were retrospectively enrolled. In addition, 113 of the 282 patients received additional contrast-enhanced MRI scans. We separated the participants into a development cohort and an external test cohort. The development cohort consisted of patients from one center and the external test cohort consisted of patients from two other centers. Two MRI-based DLRNs for prediction of tumor relapse after resection of STS were established. We universally tested the DLRNs and compared them with other prediction models constructed by using widespread adopted predictors (i.e., staging systems and Ki67) instead of radiomics features.

RESULTS

The DLRN1 model incorporated plain MRI-based radiomics signature into the clinical data, and the DLRN2 model integrated radiomics signature extracted from plain and contrast-enhanced MRI with the clinical predictors. Across both study sets, the two MRI-based DLRNs had relatively better prognostic capability (C index ≥ 0.721 and median AUC ≥ 0.746; p < 0.05 compared with most other models and predictors) and less opportunity for prediction error (integrated Brier score ≤ 0.159). The decision curve analysis indicates that the DLRNs have greater benefits than staging systems, Ki67, and other models. We selected appropriate cutoff values for the DLRNs to divide STS recurrence into three risk strata (low, medium, and high) and calculated those groups' cumulative risk rates.

CONCLUSION

The DLRNs were shown to be a reliable and externally validated tool for predicting STS recurrence by comparing with other prediction models.

KEY POINTS

• The prediction of a high recurrence rate of STS before emergence of local recurrence can help to determine whether more active treatment should be implemented. • Two MRI-based DLRNs for prediction of tumor relapse were shown to be a reliable and externally validated tool for predicting STS recurrence. • We used the DLRNs to divide STS recurrence into three risk strata (low, medium, and high) to facilitate more targeted postoperative management in the clinic.

[French ccAFU guidelines - update 2020-2022: retroperitoneal sarcoma]

OBJECTIVE

- To update French urological guidelines on retroperitoneal sarcoma.

MATERIALS AND METHODS

- Comprehensive Medline search between 2018 and 2020 upon diagnosis, treatment and follow-up of retroperitoneal sarcoma. Level of evidence was evaluated.

RESULTS

- Chest, abdomen and pelvis CT is mandatory to evaluate any suspected retroperitoneal sarcoma. MRI sometimes helps surgical planning. Before histological confirmation through biopsy, the patient must be registered in the French sarcoma pathology reference network. The biopsy standard should be an extraperitoneal coaxial percutaneous sampling before any retroperitoneal mass therapeutic decision. Surgery is retroperitoneal sarcoma cornerstone. The main objective is grossly negative margins and can be technically challenging. Multimodal treatment risks and benefits must be discussed in multidisciplinary teams. The relapse rate is related to tumor grade and surgical margins. Reported Negative margins rate thus encourage surgery in high-volume centers.

CONCLUSION

- Retroperitoneal sarcoma prognosis is poor and closely related to the quality of initial management. Centralization through dedicated sarcoma pathology network in a high-volume center is mandatory.

Management of myxoid liposarcoma of the extremity

Myxoid liposarcoma (MLPS) is the second most common type of LPS after the well differentiated LPS. MLPS is primarily localized to the extremities. The incidence of LPS is ~2 per million worldwide. MLPS accounts for ~30% of all LPS cases. MLPS is usually encountered in adults, but can also occur in younger individuals more than other types of LPS. MLPS can be divided into low- and high-grade subtypes, which present with differences in patient prognosis and outcome. Methods of tumor management include surgery, radiotherapy and chemotherapy; however, there is no unified treatment based on tumor characteristics alone. The present manuscript reviews the surgical management, radiotherapeutic and chemotherapeutic approaches reported in the literature for different types of MLPS in the extremities, as well as the post-treatment outcomes. In addition, the present review provides an evidence-based management plan for MLPS in the form of an organogram based on specific tumor and patient parameters.

Outcome after surgical resection of multiple recurrent retroperitoneal soft tissue sarcoma

INTRODUCTION

Local recurrences (LR) and distant metastases (DM) are common in retroperitoneal soft tissue sarcoma (RPS). Longer time to recurrence and resection of the recurrent lesion have been identified as beneficial prognostic factors for overall survival (OS) upon first tumor relapse. However, prognostic factors concerning OS upon subsequent recurrences are scarcely defined. In this study, we aimed to identify prognostic factors for post-relapse outcome in multiple recurrent RPS.

METHODS

Patients undergoing resection of primary and recurrent RPS at the University Hospital Heidelberg were retrospectively analyzed. Multivariable Cox regression analyses were performed to identify predictors of overall, LR- and DM-free survival. Subgroup analyses were performed for liposarcoma and leiomyosarcoma patients.

RESULTS

201 patients with primary disease, 101 patients with first, 66 patients with second and 43 patients with third LR as well as 75 patients with DM were analyzed. More than 12 months to recurrence and resection of recurrence were associated with improved OS after resection of first and second LR (5-year OS for first/second LR; resection: 64%/62%, no resection: 20%/46%). Gross macroscopic incomplete resection of first (p < 0.001), second (p = 0.001), and third recurrences (p < 0.001) was an independent prognostic factor for poor OS.

CONCLUSION

Development of LR and DM is frequent in RPS. Once a tumor relapsed, patients benefit from tumor resection not only in case of first, but also in case of subsequent recurrences.

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.

Inferior vena cava reconstruction with a superficial femoral vein graft after resection of a venous leiomyosarcoma

Leiomyosarcoma is a rare malign neoplasm, representing about 5-7% of all tissue sarcomas while inferior vena cava leiomyosarcomas accounts for only 1%. This paper presents the case of a 74 years old patient that was diagnosed with an abdominal venous leiomyosarcoma involving the inter-renal segment of the inferior vena cava. Tumor was treated by complete in bloc resection. Reconstruction of the vascular axis was performed with an autologous venous tube graft achieved with segments of the right superficial femoral vein. Recurrent free survival and freedom from local or systemic recurrence was observed at 2 years after the intervention thanks to the aggressive radical surgical management.