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

Liposarcoma: Novel Approaches to Systemic Therapy and Multidisciplinary Care

Retroperitoneal well-differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS) are rare tumors presenting as bulky abdominal tumors requiring multidisciplinary management in high-volume centers. Surgery is the mainstay of treatment through complete en bloc resection with the goal of achieving macroscopically complete resection, with a single specimen encompassing the tumor and involved contiguous organs. Preoperative radiation therapy is not standard of care and the role of preoperative chemotherapy is under investigation. If the tumor is not resectable or metastatic, the preferred treatment is doxorubicin-based chemotherapy in the case of DDLPS, whereas WDLPS are generally thought of as chemo-resistant.

Local Control in Soft Tissue Sarcomas

Soft tissue sarcoma is a rare heterogeneous group of tumors made up of over 100 histologic types and subtypes. Expert pathology review is crucial to confirm the correct diagnosis prior to treatment. Multidisciplinary discussion and management at an expert center is strongly recommended given the many nuances of treatment. Wide resection +/- preoperative radiotherapy is recommended in most extremity and trunk wall STS patients, while a minority may also require perioperative medical therapy. Macroscopic complete resection remains the standard of care for retroperitoneal sarcoma patients, with preoperative radiotherapy recommended in selected histologic types.

Challenges and hope: latest research trends in the clinical treatment and prognosis of liposarcoma

Liposarcoma, as a complex disease, is characterized by intricate interactions between distinct histopathological subtypes and corresponding clinical outcomes, emphasizing the necessity of personalized approaches in diagnosis and treatment strategies. This malignant tumor originating from adipose tissue is classified into different subtypes with specific molecular markers, which not only distinguish them but also guide treatment directions. The main approach for treating liposarcoma is surgical resection, with the aim of complete excision and achieving clean margins (R0 resection) to minimize the risk of recurrence. This surgical principle emphasizes the critical need for precise preoperative planning, and in certain cases, the integration of neoadjuvant therapy may be needed to reduce the tumor to a surgically manageable size. In addition to surgery, systemic therapy plays a key role in the advanced stages of the disease, especially when resistance to traditional treatment arises. The emergence of novel systemic therapies, including chemotherapy, targeted therapy, and immunotherapy, has opened new avenues for treating this challenging malignancy. These systemic therapies are selected on the basis of the specific molecular features of the tumor, highlighting the importance of detailed molecular diagnostics. As our understanding of the molecular basis of liposarcoma deepens, integrating clinical and molecular features is crucial for optimizing treatment outcomes. This comprehensive approach, which combines surgical precision with systemic therapy innovations, will change the treatment landscape for patients with liposarcoma, advancing toward more personalized and effective treatment strategies.

CT-based quantification of intratumoral heterogeneity for predicting distant metastasis in retroperitoneal sarcoma

OBJECTIVES

Retroperitoneal sarcoma (RPS) is highly heterogeneous, leading to different risks of distant metastasis (DM) among patients with the same clinical stage. This study aims to develop a quantitative method for assessing intratumoral heterogeneity (ITH) using preoperative contrast-enhanced CT (CECT) scans and evaluate its ability to predict DM risk.

METHODS

We conducted a retrospective analysis of 274 PRS patients who underwent complete surgical resection and were monitored for ≥ 36 months at two centers. Conventional radiomics (C-radiomics), ITH radiomics, and deep-learning (DL) features were extracted from the preoperative CECT scans and developed single-modality models. Clinical indicators and high-throughput CECT features were integrated to develop a combined model for predicting DM. The performance of the models was evaluated by measuring the receiver operating characteristic curve and Harrell's concordance index (C-index). Distant metastasis-free survival (DMFS) was also predicted to further assess survival benefits.

RESULTS

The ITH model demonstrated satisfactory predictive capability for DM in internal and external validation cohorts (AUC: 0.735, 0.765; C-index: 0.691, 0.729). The combined model that combined clinicoradiological variables, ITH-score, and DL-score achieved the best predictive performance in internal and external validation cohorts (AUC: 0.864, 0.801; C-index: 0.770, 0.752), successfully stratified patients into high- and low-risk groups for DM (p < 0.05).

CONCLUSIONS

The combined model demonstrated promising potential for accurately predicting the DM risk and stratifying the DMFS risk in RPS patients undergoing complete surgical resection, providing a valuable tool for guiding treatment decisions and follow-up strategies.

CRITICAL RELEVANCE STATEMENT

The intratumoral heterogeneity analysis facilitates the identification of high-risk retroperitoneal sarcoma patients prone to distant metastasis and poor prognoses, enabling the selection of candidates for more aggressive surgical and post-surgical interventions.

KEY POINTS

Preoperative identification of retroperitoneal sarcoma (RPS) with a high potential for distant metastasis (DM) is crucial for targeted interventional strategies. Quantitative assessment of intratumoral heterogeneity achieved reasonable performance for predicting DM. The integrated model combining clinicoradiological variables, ITH radiomics, and deep-learning features effectively predicted distant metastasis-free survival.

ASO Practice Guidelines Series: Multidisciplinary Management of Retroperitoneal Sarcomas

Retroperitoneal sarcomas (RPS) represent a rare and biologically diverse group of malignancies, distinct from soft tissue sarcomas arising in other anatomic regions. Their deep-seated location, large size at presentation and proximity to critical structures contribute to diagnostic delays, treatment challenges, and variable oncologic outcomes, particularly when managed outside high-volume referral centers. Current international guidelines emphasize the importance of preoperative biopsy, review by a sarcoma pathologist, management in a referral center, multidisciplinary case discussion, consideration for clinical trials enrollment, and prospective database inclusion as standards of care. Given that the quality of the initial surgical resection-achieving complete macroscopic resection with margins tailored to the histologic type-remains the most important modifiable prognostic factor, adherence to international best practices in surgical and multimodal treatment is crucial to optimize patient outcomes. This article reviews contemporary management strategies for adult-type RPS, emphasizing the importance of multidisciplinary expertise.

Histology-driven tailoring of surgical approaches in retroperitoneal soft tissue sarcoma: retrospective cohort study

BACKGROUND

Histology-driven tailoring of surgical approaches for retroperitoneal soft tissue sarcoma is currently under debate. Compelling evidence assessing the role of histology-dependent extent of resection is lacking. The aim of this study was to assess outcomes of patients with primary retroperitoneal liposarcoma (LPS) or leiomyosarcoma (LMS) according to whether comprehensive (formerly 'compartmental') resection (CR) was performed.

METHODS

A retrospective study was conducted on data from patients undergoing surgical resection for LPS and LMS at Heidelberg University Hospital (2002-2019). Parameters were compared between groups with and without CR, with subgroup analyses for grading (LPS). Kaplan-Meier and Cox regression analyses were used to identify predictors of disease-specific survival (DSS), local recurrence-free survival, and distant metastasis-free survival.

RESULTS

In total, 119 patients with primary LPS and 46 patients with primary LMS were identified. DSS was improved in patients with LPS with CR (P = 0.049), and both DSS (P = 0.040) and distant metastasis-free survival (P = 0.041) were improved in the subgroup of patients with primary G3 LPS. In contrast, CR in patients with LMS was not associated with improved DSS, local recurrence-free survival, or distant metastasis-free survival. CR was associated with more severe postoperative complications (P = 0.021) and a longer hospital stay (P = 0.013) in patients with LPS, longer operation times (P < 0.010) in both patients with LPS and LMS, and increased blood loss (P = 0.008) in patients with LMS.

CONCLUSION

CR is associated with improved DSS in patients with primary LPS, which is not the case in patients with primary LMS. Given the association between CR and increased perioperative morbidity, surgical strategies for retroperitoneal soft tissue sarcoma should be individualized according to the underlying histology.

What is the primary cause of postoperative death after primary retroperitoneal sarcoma surgery in a high-volume center? A nationwide study by the French Sarcoma Group

BACKGROUND

Studies on primary retroperitoneal sarcoma (RPS) surgery report morbidity rates between 15 % and 20 % and mortality rates between 3 % and 4 %. They do not specify the causes of postoperative 90-day mortality (POM).

AIM

We aim to identify the causes of POM following primary RPS surgery and assess whether these causes were preventable.

METHODS

In this retrospective cohort study, data from French high-volume sarcoma centers (NETSARC+) were collected to identify patients who underwent surgery for primary RPS between 2015 and 2022. The causes of POM were analyzed. Preoperative risk factors were defined as Eastern Cooperative Oncology Group (ECOG) performance status of 3 or 4 and/or malnutrition. Perioperative risk factors were defined as pancreatic resection, great vessel resection or reconstruction, and/or significant bleeding.

RESULTS

Eleven NETSARC + centers provided data on 1081 patients who underwent surgery for primary RPS. Among these, 21 (1.9 %) died postoperatively. Preoperative and perioperative risk factors were identified in 18 (86 %) and 15 (71 %) of the patients, respectively. The median estimated blood loss was 1250 mL (range: 100-18,500 mL). Ten of the 21 patients (48 %) died due to hemorrhage, while respiratory failure accounted for the second most common cause of death (24 %). The third most common cause of death was digestive ischemia (14 %).

CONCLUSION

POM following primary RPS surgery in specialized sarcoma centers is low (1.9 %). While aspiration pneumonitis could be prevented by the use of a nasogastric tube, hemorrhage and mesenteric ischemia were primarily due to extensive surgical indications, highlighting the importance of careful patient selection.

SEOM-GEIS Spanish clinical guidelines for the management of soft‑tissue sarcomas (2024)

Soft-tissue sarcomas are rare, diverse malignant tumors of mesenchymal origin, requiring diagnosis and treatment by a specialized multidisciplinary team. Initial assessment includes radiology and biopsy, followed by wide surgical resection with clear margins for localized cases. Radiotherapy is recommended for large, deep, high-grade tumors or after incomplete resection, while perioperative chemotherapy may be considered for high-risk cases. In oligometastatic disease, combining local and systemic therapies is an option. Anthracycline-based chemotherapy is the first-line treatment in advanced disease, though other drugs show efficacy in certain subtypes. Given the limited options, enrolling in clinical trials is advised for patients needing further treatment.

Resection of Primary Leiomyosarcoma of the Inferior Vena Cava and Reconstruction with a Cadaveric Homograft

BACKGROUND

Leiomyosarcoma (LMS) is a rare malignancy arising from the smooth muscle, which affects the inferior vena cava (IVC) in 30-40% of cases; the cure relies on complete surgical resection,1 demanding meticulous oncological and vascular planning. The efficacy of preoperative chemotherapy is currently under investigation.2 Restoration of vessel continuity and blood flow must be tailored to each individual case. This video presents an IVC LMS case, in which the retroperitoneal sarcoma (RPS) six-stage procedure3 was customized for LMS, with IVC flow restored using a cadaveric aortic homograft.

PATIENTS AND METHODS

A 64-year-old woman presented with a 6 cm IVC mass with neoplastic thrombosis and intense PET uptake. Suspecting an IVC LMS, the tumor board recommended up-front surgery.

RESULTS

An en bloc resection of the tumor and the involved IVC segment II-III with homograft interposition was performed. The procedure involved division of the right gonadal, caudate lobe, lumbar and left adrenal veins; isolation of the IVC and renal veins; followed by cross-clamping and resection under vascular control with hemodynamic stability and no need for veno-venous bypass. Frozen margins on the IVC and renal veins were negative. Blood flow was restored using a cryopreserved cadaveric aortic homograft, trimmed to the appropriate length and implanted end-to-end on the IVC. The right renal vein was anastomosed end-to-side on the graft, while the left renal vein was reconnected using a jump graft crafted from the remaining portion of the cadaveric graft.

CONCLUSIONS

Resection of retroperitoneal leiomyosarcoma requires both oncological and vascular expertise to achieve optimal curative outcomes and restore physiological vascular flow when necessary.

Group IV Bimetallic MOFs Engineering Enhanced Metabolic Profiles Co-Predict Liposarcoma Recognition and Classification

The rarity and heterogeneity of liposarcomas (LPS) pose significant challenges in their diagnosis and management. In this work, a series of metal-organic frameworks (MOFs) engineering is designed and implemented. Through comprehensive characterization and performance evaluations, such as stability, thermal-driven desorption efficiency, as well as energy- and charge-transfer capacity, the engineering of group IV bimetallic MOFs emerges as particularly noteworthy. This is especially true for their derivative products, which exhibit superior performance across a range of laser desorption/ionization mass spectrometry (LDI MS) performance tests, including those involving practical sample assessments. The top-performing product is utilized to enable high-throughput recording of LPS metabolic fingerprints (PMFs) within seconds using LDI MS. With machine learning on PMFs, both the LPSrecognizer and LPSclassifier are developed, achieving accurate recognition and classification of LPS with area under the curves (AUCs) of 0.900-1.000. Simplified versions are also developed of the LPSrecognizer and LPSclassifier by screening metabolic biomarker panels, achieving considerable predictive performance, and conducting basic pathway exploration. The work highlights the MOFs engineering for the matrix design and their potential application in developing metabolic analysis and screening tools for rare diseases in clinical settings.

Contraindication to surgery in primary retroperitoneal sarcoma: Retrospective series on 20years of practice in a high-volume sarcoma center

INTRODUCTION

Surgery is the cornerstone treatment for retroperitoneal sarcomas (RPS). However, contraindications for unresectability are not well-documented in the literature.

AIM OF THE STUDY

This study aims to identify contraindications that prevent surgery for primary RPS in a high-volume sarcoma center.

METHODS

We retrospectively analyzed all consecutive patients treated for primary RPS at our center from 1995 to 2021.

RESULTS

Among the 452 patients treated for primary RPS, 92 (20%) were not offered surgery. The reasons for unresectability were categorized as follows: poor general health or severe comorbidities in 39 patients (42%), preoperative detection of distant metastases in 33 patients (36%), and locally advanced disease in 20 patients (22%). Locally advanced disease included vascular involvement in 14 patients (15%) and vertebral invasion in 6 patients (7%). Among the non-operated patients, 66% received chemotherapy, 16% received radiotherapy, and 5% received combined treatments. The median progression-free survival was 7months, and the median overall survival was 18months. The 1-year overall survival rate was 53%.

CONCLUSION

Contraindications for surgery in patients with primary RPS in a high-volume sarcoma center are not uncommon. The next step should be to differentiate absolute from relative (i.e., preoperative modifiable factors) contraindications.

Challenges, Treatment Strategies, and Surgical Techniques in the Management of Spermatic Cord Sarcomas

Spermatic cord sarcomas (SCS) are a group of mesenchymal tumors whose rarity and anatomical location often lead to clinical misdiagnosis such as inguinal hernia, testicular tumor, or other conditions. Any inguinoscrotal mass with suspicious characteristics should prompt clinicians to perform imaging assessments (such as ultrasound or, in uncertain cases, magnetic resonance imaging (MRI)) and refer the patient promptly to a specialized center. Histological characterization of all suspicious masses via percutaneous biopsy is recommended, with staging completed through computed tomography (CT) scan for confirmed cases. Optimal management is multidisciplinary and should consider both the tumor's histological subtype and specific characteristics of the tumor and patient. Radiotherapy and chemotherapy, while awaiting more robust data in the literature, are valuable adjuncts to surgery, which remains the cornerstone of treatment. Surgery should also be proposed for patients who initially underwent nonspecialist procedures, as a completion approach. The surgical strategy involves en bloc resection through radical orchifunicolectomy, ipsilateral hemiscrotectomy, ligation of the spermatic cord at the internal inguinal ring, and, where necessary, resection of the inguinal canal. Reconstruction may employ mesh or pedicled flaps. The prognosis of SCS, when treated at referral centers, is superior to that of mesenchymal tumors at other sites, underscoring the need for early recognition and prompt multidisciplinary care.

Optimizing imaging modalities for sarcoma subtypes in radiation therapy: State of the art

The choice of imaging modalities is essential in sarcoma management, as different techniques provide complementary information depending on tumor subtype and anatomical location. This narrative review examines the role of imaging in sarcoma characterization and treatment planning, particularly in the context of radiation therapy (RT). Magnetic resonance imaging (MRI) provides superior soft tissue contrast, enabling detailed assessment of tumor extent and peritumoral involvement. Computed tomography (CT) is particularly valuable for detecting osseous involvement, periosteal reactions, and calcifications, complementing MRI in sarcomas involving bone or calcified lesions. The combination of MRI and CT enhances tumor delineation, particularly for complex sites such as retroperitoneal and uterine sarcomas, where spatial relationships with adjacent organs are critical. In vascularized sarcomas, such as alveolar soft-part sarcomas, the integration of MRI with CT or MR angiography facilitates accurate mapping of tumor margins. Positron emission tomography with [18 F]-fluorodeoxyglucose ([18 F]-FDG PET) provides functional insights, identifying metabolically active regions within tumors to guide dose escalation. Although its role in routine staging is limited, [18 F]-FDG PET and emerging PET tracers offer promise for refining RT planning. Advances in artificial intelligence further enhance imaging precision, enabling more accurate contouring and treatment optimization. This review highlights how the integration of imaging modalities, tailored to specific sarcoma subtypes, supports precise RT delivery while minimizing damage to surrounding tissues. These strategies underline the importance of multidisciplinary approaches in improving sarcoma management and outcomes through multi-image-based RT planning.

Aggressive surgical approach with major vascular resection for retroperitoneal sarcomas

BACKGROUND

En bloc resection of adjacent structures, including major vessels, is often required to achieve negative margins in retroperitoneal sarcoma (RPS). However, the effect of vascular involvement and different reconstruction techniques in patients undergoing vascular resection remains unclear. This study investigated the morbidity, mortality, and long-term survival of patients who underwent an aggressive surgical approach with vascular resection for RPS.

METHODS

We analyzed a prospectively maintained database of patients who underwent surgical resection (with or without vascular resection) for RPS between 2015 and 2020. The primary endpoint was long-term overall survival (OS).

FINDINGS

The study population comprised 252 patients. Postoperative morbidity, mortality, and OS did not differ significantly between the vascular and no vascular resection groups. Among patients with vascular involvement, those who underwent aggressive surgical approach with vascular resection had a significantly higher OS (66.3 months vs. 25.6 months) compared to those who underwent palliative resection, without an increase in mortality or complication rate. No significant differences were observed in postoperative morbidity, 30-day mortality, or estimated median OS between patients who underwent primary repair and reconstruction.

CONCLUSIONS

In patients with RPS with vascular involvement, an aggressive surgical approach with vascular resection achieved optimal clinical outcomes. Vascular reconstruction techniques had no impact on clinical outcomes.

Celiac ganglion resection as an intraoperative factor associated with delayed gastric emptying in retroperitoneal sarcoma surgery: A multicentric prospective cohort study

INTRODUCTION

Delayed gastric emptying (DGE) is a common but underexplored complication following retroperitoneal sarcoma surgery. The celiac ganglion, often excised during these procedures, plays a key role in gastric motility and its removal may contribute to DGE development.

MATERIALS AND METHODS

Data from 42 patients were prospectively collected at three referral centers. DGE was graded according to the International Study Group of Pancreatic Surgery (ISGPS) classification. Intraoperative celiac ganglion resection was categorized as none, partial, or complete. The primary endpoint was the effect of celiac ganglion resection on clinically relevant DGE (ISGPS grade B-C). The secondary endpoint was whether resection was an independent predictor of DGE.

RESULTS

One patient was excluded due to early postoperative mortality. Among the remaining 41 patients, DGE occurred in 60.97 % of cases, with 26.83 % classified as clinically relevant. Partial celiac ganglion resection was performed in 31.7 % of patients, while complete resection occurred in 14.6 %. Univariate analysis showed that complete resection was associated with 22.5-fold increased risk of clinically relevant DGE (p = 0.011). Multivariate analysis confirmed this association, identifying complete resection as an independent risk factor (OR = 40.56, p = 0.013).

CONCLUSIONS

Clinically relevant DGE is frequent after retroperitoneal sarcoma surgery. Complete celiac ganglion resection significantly increases the risk of DGE, emphasizing the importance of careful surgical planning and comprehensive preoperative patient counselling. Implementing standardized perioperative protocols, including early nutritional support, may help mitigate its impact and improve postoperative recovery.

The Impact of Perioperative Radiotherapy on Disease-Specific Survival in Patients with Localized Retroperitoneal Liposarcoma: A Population-Based Propensity-Score Matched Analysis

BACKGROUND

The impact of radiotherapy on the oncologic outcome of retroperitoneal liposarcoma (RPLS) remains controversial. The aim of this study was to evaluate the effect of radiotherapy on disease-specific survival (DSS) in a cohort of patients with RPLSs.

METHODS

In this population-based, retrospective cohort study, patients with localized RPLSs who underwent surgical therapy were identified from the Surveillance, Epidemiology, and End Results-17 cancer registry program. After propensity-score matching for potential confounders, multivariable logistic and Cox regression analyses were used to examine factors associated with DSS and radiotherapy.

RESULTS

From 2004 to 2020, 1692 patients with localized RPLS who underwent surgical therapy were identified (84.2%  White, 44.6% female, mean age 62 years). Of those patients, 393 patients (23.2%) received perioperative radiotherapy. Patients who received radiotherapy had a higher rate of tumor size between 10 and 20 cm and unknown tumor grading. After propensity-score matching, multivariable adjusted Cox regression and Kaplan-Meier survival analysis demonstrated no improvement of DSS for patients who underwent radiotherapy (hazard ratio 1.04, confidence interval 0.81-1.32; log-rank p = 0.47). Patient age ≥80 years, larger tumor size, and tumor grading G3 versus G1/2 were associated with an increased risk of death due to RPLS. Subgroup analyses stratified by grading showed similar outcomes.

CONCLUSIONS

The administration of perioperative radiotherapy did not improve DSS in patients undergoing surgery for localized RPLS in this population-based study. Therefore, the use of perioperative radiotherapy in these patients may be questioned. However, the findings should be interpreted with caution due to the inherent limitations of the Surveillance, Epidemiology, and End Results (SEER) database.

Preoperative Radiation Therapy is Not Associated with Postoperative Complications in Patients with Retroperitoneal Sarcoma

BACKGROUND

The role of preoperative radiation therapy (RT) in the management of retroperitoneal sarcomas (RPS) remains controversial. A legitimate concern is the potential for worse outcomes after surgery for RPS with preoperative RT.

OBJECTIVE

The purpose of this study was to evaluate the impact of preoperative (± intraoperative) RT on postoperative complications in patients undergoing surgery for RPS.

METHODS

A total of 99 patients who underwent curative-intent surgery for primary RPS of any histology after preoperative RT from 2003 to 2021 were analyzed. Univariate and multivariate logistic regression analyses were performed to identify factors associated with postoperative morbidity and mortality.

RESULTS

The median preoperative RT dose was 57.4 Gy, and 17 patients received intraoperative RT to a median dose of 10 Gy. The median number of organs resected was two. Postoperative complications within 30 days of surgery occurred in 47% of patients, including severe complications (Clavien-Dindo grades ≥IIIa) in 20% of patients. The 90-day mortality rate was 2%. On multivariate analysis, concomitant vascular resection was the only significant predictor of severe postoperative complications (odds ratio 8.76; p = 0.0069). Despite increasing median preoperative RT doses from 50.4 Gy in 2003-2012 to 63 Gy (on a clinical trial) in 2013-2021, severe postoperative morbidity rates actually decreased from 26.3% to 16.1% (p = 0.303).

CONCLUSION

The administration of preoperative (± intraoperative) RT to patients with RPS resulted in similar postoperative complications as reported after surgery alone. Continuous advances in surgical and radiotherapeutic expertise resulted in lower complication rates over time despite increasing radiation doses.

Management strategies following recurrence of resected retroperitoneal sarcoma: A 10-year observational study

BACKGROUND

In management of retroperitoneal sarcoma (RPS), radical resection remains the main facet of curative treatment. While recurrence is common, a clear consensus does not exist around optimal post-operative surveillance and post recurrence management.

MATERIALS AND METHODS

Patients undergoing resection for RPS over a 10 year period were identified through a prospectively maintained database. Patients underwent surveillance imaging with intensity dependant on risk of disease recurrence. Rates of recurrence, post recurrence therapeutic modalities and outcomes were recorded.

RESULTS

105 patients underwent primary resection of RPS in the study period. 5-year survival of patients with low-risk and high-risk of disease recurrence was 74 % and 49 % respectively. Of the 58 patients that suffered disease recurrence, 29 patients with primary recurrence underwent further surgery, 10 patients with oligo-metastatic disease underwent curative intent management and 12 patients underwent chemotherapy (median survival: 6.5 vs 4.0 vs 1.7 years, 5-year survival: 71 % vs 45 % vs 12 %). The cost of surveillance imaging to identify recurrence treated with curative intent was calculated at £5434 and £2269 for low- and high-risk disease respectively.

CONCLUSIONS

Post resectional surveillance detects recurrence, allowing further intervention. Such strategies include surgical re-resection, interventional ablation or ablative radiotherapy of oligometastatic disease, and palliative chemotherapy; multifaceted therapeutic options which sit within current management guidelines. Patients with local recurrence who underwent further resection and those who underwent curative-intent management for other metastatic disease had improved outcomes compared to patients with widespread disease recurrence who underwent systemic chemotherapy. The costs of surveillance imaging fit within current UK healthcare economic policy guidelines.

Response to Central Boost Radiation Therapy in Unresectable Retroperitoneal Sarcoma: A Case Series

Purpose

Optimal treatment of retroperitoneal sarcoma (RPS) remains undefined. Here, we report the feasibility of using high-dose boost radiation (3-4 Gy) to the central part of the tumor in patients with unresectable RPS.

Methods and Materials

Five patients with unresectable RPS were treated with radiation therapy using a central boost technique with intensity modulated radiation therapy. On average, doses of 25 Gy to 45 Gy were delivered to the outer part of the tumor (planning target volume 1), while the central part of the tumor (planning target volume 2) received a 56 Gy to 75 Gy physical dose, which translates to a 62.67 Gy to 87.5 Gy equivalent dose in 2 Gy fractions (EQD2). To minimize radiation toxicity to the adjacent bowel and other organs, we used sequential, interdigitated, or simultaneous integrated boost (SIB) techniques.

Results

In this case series of variable RPS histology, the median survival postradiation therapy was 30 months. Three of the 5 patients had clinically stable local disease on follow-up scans, and none of the patients experienced clinically significant toxicity.

Conclusions

In summary, in this small case series of 5 patients, treatment was tolerated well, and excellent local responses were observed regardless of the timing of the central boost. Given the high rates of metastatic disease that developed in responding patients, effective systemic therapy will likely be needed for unresectable RPS treated with aggressive radiation therapy to the central part of the tumor.

Temporal variation in nutritional status and preoperative anemia among patients with retroperitoneal soft tissue sarcoma: a retrospective longitudinal cohort study

PURPOSE

Optimal management of retroperitoneal soft tissue sarcoma (RPS) often requires extensive tumor resections, frequently involving gastrointestinal organs. The impact of these procedures on the nutritional status and hemoglobin (Hb) levels of RPS patients remain unexplored. In this study, we aimed to evaluate preoperative nutritional status as well as the prevalence of anemia in RPS patients, and to investigate longitudinal changes throughout the disease course in order to identify potential strategies for prehabilitation.

MATERIALS AND METHODS

Patients undergoing resection of primary and recurrent RPS at Heidelberg University Hospital were retrospectively analyzed. Changes in nutritional parameters and Hb levels throughout the disease course were analyzed using hierarchical linear regression models. Multivariable Cox regression analyses were performed to identify independent predictors of overall survival. Subgroup analyses were conducted for primary tumors, first, second and third recurrences.

RESULTS

Amongst 370 patients analyzed, comprising 219 with primary disease, we observed neither a significant prevalence of preoperative malnutrition nor notable changes in BMI or serum albumin levels throughout the disease course. Preoperative anemia affected up to 40% of RPS patients, and Hb levels significantly decreased over the course of the disease (p = 0.022), particularly in correlation with the number of tumor resections performed (p = 0.010). Low preoperative Hb levels were associated with increased 30-day mortality and they were identified as an independent prognostic factor for shorter overall survival in primary RPS as well as in second and third recurrences.

CONCLUSION

Anemia screening should be performed preoperatively and during regular follow-ups to enable early-on therapy, thus potentially improving patient outcomes in RPS.

The sarcoma ring trial: a case-based analysis of inter-center agreement across 21 German-speaking sarcoma centers

PURPOSE

The management of soft tissue sarcoma (STS) at reference centers with specialized multidisciplinary tumor boards (MTB) improves patient survival. The German Cancer Society (DKG) certifies sarcoma centers in German-speaking countries, promoting high standards of care. This study investigated the variability in treatment recommendations for localized STS across different German-speaking tertiary sarcoma centers.

METHODS

In this cross-sectional case-based survey study, 5 anonymized patient cases with imaging data of localized STS were presented to MTBs of 21 German-speaking tertiary referral hospitals. Centers provided recommendations on treatment sequence and modalities, along with the consensus level within their MTB. Agreement percentages were calculated, and consensus levels were rated on a scale of 1 to 10.

RESULTS

Five patient cases were discussed resulting in 105 recommendations. Agreement percentages for case 1 to 5 were 14.3%, 61.9%, 33.3%, 52.4% and 9.3%, with a median agreement percentage of 33.3%. Grouping pre- and postoperative therapies as "perioperative" and including recommendations with and without regional hyperthermia raised the median agreement to 47.6%. The mean consensus level within each center across all 5 cases was 9.5.

CONCLUSION

This first case-based analysis of inter-center agreement for STS management in German-speaking countries reveals low inter-center agreement but high intra-center consensus. Our study includes nearly all tertiary sarcoma centers in German-speaking countries, affirming its strong external validity. These findings suggest potential and clinically very relevant differences in treatment standards among sarcoma centers. Enhanced case-based exchanges and collaborative efforts are needed to reduce discrepancies and standardize the management of STS patients.

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.

Total retroperitoneal lipectomy improves prognosis in patients with primary retroperitoneal liposarcoma: a comparative study

Background

Retroperitoneal liposarcoma (RPLS) is the most common soft tissue sarcoma originating in the retroperitoneal space. Although surgery is the standard treatment, recurrence remains frequent. In this study, we aimed to explore the safety and efficacy of total (ipsilateral) retroperitoneal lipectomy (TRL) compared to traditional complete resection (CR) for primary RPLS.

Methods

We retrospectively analyzed patients with primary RPLS treated at our center between January 2014 and December 2020. Univariate and multivariable Cox regression analyses assessed the impact of demographic, operative, and clinicopathological variables on recurrence-free survival (RFS) and overall survival (OS). Kaplan-Meier plots illustrated RFS and OS, and the log-rank test compared time-to-event distributions.

Results

A total of 81 patients were included in the final analysis: 37 in the CR group and 44 in the TRL group. Demographic and clinicopathologic parameters were comparable between the two groups. Post-operative morbidity occurred in 30.9% of cases, with 15 (40.5%) in the CR group and 10 (22.7%) in the TRL group (P=0.086). There were 9 cases of severe complications at grade 3 or higher, with 5 cases in the CR group and 4 cases in the TRL group. There was no significant difference between the two groups (P=0.314). The TRL group demonstrated improved RFS and OS, particularly among dedifferentiated liposarcoma (DDLS) patients.

Conclusions

Total retroperitoneal lipectomy (TRL) appears to be a safe procedure that enhances survival outcomes in patients with primary RPLS. Further studies are needed to validate these findings.

Diagnosis and management of dedifferentiated liposarcoma: A multidisciplinary position statement

Dedifferentiated liposarcoma (DDLPS) is a malignant mesenchymal neoplasm in desperate need of novel therapeutic approaches. Often occurring in conjunction with well-differentiated liposarcoma (WDLPS), DDLPS can behave more aggressively and exhibits a significant risk for developing recurrence or metastatic disease when compared to its well-differentiated counterpart. A multidisciplinary approach is critically important, particularly for patients with localized disease, as disease presentations are often complex, and the management of patients has become increasingly nuanced as treatment approaches have become more refined. Expert pathology review and appropriate application of diagnostic molecular techniques are key components of DDLPS diagnosis and also reflect an improved understanding of the underlying pathogenesis of the disease. Systemic therapies remain limited for DDLPS, but novel therapies targeting important underlying molecular drivers have resulted in ongoing clinical trials aiming to improve outcomes for patients with advanced disease. In recognition of the increased activity and interest within the DDLPS field, a multidisciplinary group of nationally recognized experts in medical oncology, surgical oncology, radiation oncology, and pathology was convened to summarize key insights. This position paper highlights important points from the meeting and provides evidence-based recommendations for practicing clinicians.

Preoperative nutritional support to tackle morbidity in multivisceral resection for retroperitoneal sarcoma. Early outcomes from a novel nutritional prehabilitation program in a prospective cohort

OBJECTIVE

Evaluate the feasibility and outcomes of the implementation of a routinely prehabilitation nutritional program (PNP) in retroperitoneal sarcoma (RPS) patients.

SUMMARY BACKGROUND DATA

Rate of preoperative malnutrition is scarcely evaluated in RPS patients and the efficacy of a PNP in detecting and reverting malnutrition has not been studied.

METHODS

Prospective study in a high-volume reference center for RPS; adult patients with primary or persistent RPS deemed surgically resectable were enrolled in a PNP.

RESULTS

119 patients underwent surgery for RPS at Fondazione IRCCS Istituto Nazionale dei Tumori in Milan, 73 (61.3 %) were enrolled in the PNP while the remaining served as control cohort. 43.8 % (32/73), 28.8 % (21/73), and 27.4 % (20/73) were classified as non-malnourished, moderately malnourished, and severely malnourished at diagnosis, respectively. Preoperative nutritional support was provided to 35 out of 73 patients (47.9 %). Among untreated patients 20 of 38 (52.6 %) experienced a preoperative worsening of their nutritional status, whereas among those in the prehabilitation program 16 of 35 (45.7 %) showed improvement. Surgical complications did not significantly differ between malnourished and non-malnourished patients, potentially due to increased use of diverting stomas in malnourished patients to prevent infectious complications. Reversal of initial malnutrition correlated with better postoperative outcomes, as evidenced by lower rates of severe complications (OR: 0.18, 95%CI 0.04-0.75, p = 0.02) and a lower Comprehensive Complication Index (OR: -0.28, 95%CI -0.51 to -0.06, p = 0.02) in multivariate analysis.

CONCLUSIONS

The implementation of a prehabilitation nutritional program brought relevant benefits in terms of postoperative morbidity.

Extent of macroscopic vascular invasion predicts distant metastasis in primary leiomyosarcoma of the inferior vena cava

BACKGROUND

In retroperitoneal leiomyosarcoma (RP LMS), the predominant issue is distant metastasis (DM). We sought to determine variables associated with this outcome and disease-specific death (DSD).

METHODS

Data were retrospectively collected on patients with primary RP LMS treated at a high-volume center from 2002 to 2023. For inferior vena cava (IVC)-origin tumors, the extent of macroscopic vascular invasion was re-assessed on each resection specimen and correlated with preoperative cross-sectional imaging. Crude cumulative incidences were estimated for DM and DSD and univariable and multivariable models were performed.

RESULTS

Among 157 study patients, median tumor size was 11.0 cm and 96.2% of cases were intermediate or high grade. All patients underwent complete resection, 56.7% received chemotherapy (43.9% neoadjuvant) and 14.6% received radiation therapy. Only tumor size and grade and not site of tumor origin (e.g., IVC vs. other) were associated with DM and DSD (p < 0.05). Among 64 patients with IVC-origin tumors, a novel 3-tier classification was devised based on the level of intimal disruption, which was associated with both DM (p = 0.007) and DSD (0.002).

CONCLUSION

In primary RP LMS, only tumor size and grade are predictive of DM and DSD. In IVC-origin tumors, the extent of macroscopic vascular invasion is also strongly predictive of these outcomes.

Radiomic features of primary retroperitoneal sarcomas: a prognostic study

BACKGROUND

Risk-stratification of patients with retroperitoneal sarcomas (RPS) relies on validated nomograms, such as Sarculator. This retrospective study investigated whether radiomic features extracted from computed tomography (CT) imaging could i) enhance the performance of Sarculator and ii) identify G3 dedifferentiated liposarcoma (DDLPS) or leiomyosarcoma (LMS), which are currently consider in a randomized clinical trial testing neoadjuvant chemotherapy.

METHODS

Patients with primary localized RPS treated with curative-intent surgery (2011-2015) and available pre-operative CT imaging were included. Regions of interest (ROIs) were manually annotated on both unenhanced and portal venous phase acquisitions. Top performing radiomic features were selected with outcome-specific random forest models, through generation of replicative experiments (contexts) where patients were split into training and testing sets. Endpoints were overall and disease-free survival (OS, DFS). Prognostic models for DFS and OS included the top five selected radiomic features and the Sarculator nomogram score. Models accuracy was assessed with Harrell's Concordance (C-)index.

RESULTS

The study included 112 patients, with a median follow-up of 77 months (IQR 65-92 months). Sarculator alone achieved a C-index of 0.622 and 0.686 for DFS and OS, respectively. Radiomic features only marginally enhanced the prediction accuracy of Sarculator for OS (C-index=0.726, C-index gain: 0.04) or DFS (C-index=0.639, C-index gain: 0.017). Finally, radiomic features identified patients with G3 DDLPS or LMS with an accuracy of 0.806.

CONCLUSION

Radiomic features marginally improved the performance of Sarculator in RPS. However, they accurately identified G3 DDLPS or LMS at diagnosis, potentially improving patients selection for neoadjuvant treatments.

Comparing epidemiological and clinical data from RPS patients documented in a German cancer registry to a cohort from TARPSWG reference centres

PURPOSE

Retroperitoneal sarcomas (RPS) are rare, heterogeneous tumours. Treatment recommendations are mainly derived from cohorts treated at reference centres. The applicability of data from cancer registries (CR) is controversial. This work compares CR and TARPSWG (Transatlantic Australasian Retroperitoneal Sarcoma Working Group) data to assess the representativeness of the TARPSWG and the applicability of the CR data.

METHODS

TARPSWG cohort has previously been described. The CR Baden-Württemberg cohort includes patients with primary RPS M0 (years 2016-2021, ICD-10 C.49.4/5, C48.x) who underwent surgery within 12 months. Only patients with sarcoma-typical histology codes as used for the German Cancer Society certification system were included. Patient, tumour and therapy factors as well as survival times were compared with Chi2-test, Kaplan Meier curves, and adjusted models.

RESULTS

1000 (TARPSWG) and 364 (CR) patients were included. CR patients were older (median: 64 years vs. 58 years), had more high-grade tumours (FNCLCC 3 48.1% vs. 27.4%, p < 0.0001) and the 5-year survival rate was significantly lower (56.3% vs. 67.9%, p = 0.0015). The proportions of dedifferentiated liposarcoma (CR 37.1% vs. 37.0%) and leiomyosarcoma (CR 20.1% vs. 19.2%), and patterns of recurrence in these most frequent RPS subtypes were similar.

CONCLUSION

ICD-O/ICD 10 based filters appear to be a valid tool for extracting RPS cases from CR. The similar distribution and biological behavior of distinct RPS subtypes suggests that TARPS-WG are representative, and CR data may be used to verify recommendations derived from reference centre cohorts. Complementary use of data from different sources warrants further investigation in rare cancers.

Liposarcoma: A Journey into a Rare Tumor's Epidemiology, Diagnosis, Pathophysiology, and Limitations of Current Therapies

Sarcomas are a heterogeneous group of neoplasms that develop from bone and soft tissue. Approximately 80% of sarcomas affect soft tissue, with liposarcoma being one of the most common types, accounting for approximately 13-20% of all soft-tissue sarcomas. Per the World Health Organization, liposarcoma can be broadly classified into four different subtypes based on histologic examination: well-differentiated liposarcoma (WDLS)/atypical lipomatous tumors (ALT), dedifferentiated liposarcoma (DDLS), myxoid liposarcoma (MLS), and pleomorphic liposarcoma (PLS). WDLS/ALT is the most common liposarcoma subtype, accounting for approximately 31-33% of liposarcomas; DDLS accounts for 20%; MLS accounts for 19%; and PLS, the least common subtype, represents 7-8% of liposarcomas. Sarcoma diagnosis is challenging because of its rarity, intrinsic complexity, and diagnostic technological complexity. Sarcomas are misdiagnosed in approximately 30% of cases, leading to delays in diagnosis and access to appropriate therapy and clinical trials. Furthermore, treatment options are limited for those diagnosed with liposarcoma. This review discusses the epidemiology, pathology, and treatment options currently available for liposarcoma.

The Use of Palliative Therapy in Patients With Advanced Retroperitoneal Sarcoma

INTRODUCTION

Advanced retroperitoneal sarcoma (RPS) can include unresectable locoregional disease, systemic or multifocal intra-abdominal metastasis, or abdominal sarcomatosis, all of which are associated with high morbidity and may be addressed through palliative therapy. Current trends in the use of palliative therapy and factors associated with its use in patients with advanced RPS remain largely unexplored. The objectives of this study are to (1) describe the temporal trend in the use of palliative therapy and (2) identify factors associated with its use in patients with advanced RPS in the United States from 2004 to 2020.

METHODS

This study is a retrospective cohort study using the National Cancer Database. We identified adult patients who were diagnosed with advanced RPS (American Joint Committee on Cancer stages III and IV) from 2004 to 2020. We performed a trend analysis to describe the use of palliative therapy over time, followed by univariable and multivariable logistic regression analyses to identify predictors of palliative therapy use in this patient population.

RESULTS

A total of 6149 patients with advanced RPS were identified, of which only 383 used palliative therapy, including surgery (n = 28), radiation therapy (n = 87), systemic therapy (n = 115), pain management (n = 61), combination therapy (n = 55), or other palliative therapy (n = 37). The proportion of patients using palliative therapy increased significantly from 2.6% in 2004 to 6.5% in 2020 (Ptrend < 0.001). On multivariable logistic regression, age (odds ratio [OR] 1.03, 95 confidence interval [CI] 1.01-1.04), year of diagnosis (OR 1.05, 95 CI 1.02-1.08), lack of insurance (OR 2.18, 95 CI 1.17-4.04), community cancer program status (OR 1.83, 95 CI 1.05-3.19), stage IV disease (OR 5.19, 95 CI 4.49-7.79), and rhabdomyosarcoma (OR 2.75, 95 CI 1.32-5.72) histology were found to be predictors of palliative therapy use.

CONCLUSIONS

This study sheds light on the evolving landscape of palliative therapy use for patients with advanced RPS in the United States from 2004 to 2020. The observed gradual increase in the use of palliative therapy underscores the growing recognition of its importance in managing the unique challenges associated with this complex disease. Despite this positive trend, the persistently low overall rates highlight the need for further efforts to enhance awareness and accessibility of palliative therapy for this patient population.

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.

Surgical Outcome in Retroperitoneal Sarcoma Surgery: Accuracy of P-POSSUM, ACS-NSQIP, and Inflammatory Biomarkers Prognostic Index (IBPI) Risk-Calculators for Prediction of Severe and Overall Morbidity

INTRODUCTION

Retroperitoneal sarcoma often requires comprehensive resection, leading to severe postoperative morbidity. The lack of disease-procedure specific tools for morbidity risk and the questionable accuracy of existing tools (ACS-NSQIP and P-POSSUM) in RPS surgery drove this study to assess these calculators' accuracy.

METHODS

Retrospective analysis of primary RPS cases undergoing surgery at two sarcoma-referral centers was conducted. Predicted morbidity/mortality rates at 90 days postsurgery, classified by Clavien-Dindo (CD) and Comprehensive Complication Index (CCI), were compared with observed data. Accuracy was assessed by Brier Score and area under the curve (AUC). Inflammatory Biomarkers Prognostic Index (IBPI) also was tested.

RESULTS

A total of 567 patients (median age 62 years; 53.6% male) with a median of four resected organs were included. 59% experienced surgical complications by 90 days postoperation, graded CD ≥ 3 in 30.5%, median CCI 20.9, with a mortality rate of 1.6% (8/567). Reoperation was required in 68 of 567 patients (12%). Thirty-day mortality was 1.1%. Severe complications occurred after 30th postoperative day in 3.5% cases. ACS-NSQIP predicted below-average complication for 65.1%, average for 16.9%, and above-average for 18% of patients. P-POSSUM predicted a 66% rate of morbidity and 4% mortality. None of the prediction tools were accurate, with Brier scores ranging 0.155-0.231 and no AUC ≥ 0.7. IBPI accuracy for predicting severe infective complication was low (AUC 0.58, Brier 0.161).

CONCLUSIONS

The significant morbidity burden after MVR necessitates reliable evaluation, especially in frail patients. Given the limitations of ACS-NSQIP and P-POSSUM, a dedicated prediction tool for perioperative events in RPS candidates for MVR needs urgent development.

Intraoperative radiotherapy might not serve as a standard therapy for retroperitoneal liposarcoma: insights from a population-based propensity score-matched study

BACKGROUND

Difficulty in achieving complete resection leads to a poor prognosis for retroperitoneal soft tissue sarcoma, hence emphasizing the significance of adjuvant treatment. The benefit of preoperative radiotherapy for retroperitoneal liposarcoma was initially demonstrated by the STRASS trial. However, the impact of intraoperative radiotherapy (IORT) on retroperitoneal liposarcoma remains unexplored.

METHOD

Patients with retroperitoneal liposarcoma were identified in the Surveillance, Epidemiology, and End Results (SEER) database, treated between 2000 and 2019. Subsequently, a 1:1 propensity score-matched (PSM) analysis was conducted based on variables identified from a multivariate analysis. T-tests were used to assess differences in normally distributed continuous variables, while the rank-sum test was applied to variables that did not follow a normal distribution. The chi-squared test was utilized to evaluate differences in categorical variables. Ultimately, survival analysis was performed using SPSS to evaluate patient prognosis.

RESULT

A total of 2129 patients with retroperitoneal liposarcoma were included in our study. Age, sex, histology, grading, chemotherapy, and tumor size as independent prognostic risk factors for these patients through multivariate Cox regression analysis. Subsequently, 66 patients were included in the survival analysis through PSM, with 33 patients receiving IORT. Finally, the survival analysis revealed that there was no difference in overall survival among patients with retroperitoneal liposarcoma, regardless of whether they received IORT or not (p= 0.711).

CONCLUSION

As an exploratory study, our findings suggest that patients may not derive benefit from intraoperative radiotherapy. These observations are intended to lay the groundwork for future prospective clinical studies.

Comprehensive treatment strategy for improving surgical resection rate of retroperitoneal sarcomas: a histology-specific approach narrative review

Retroperitoneal sarcoma (RPS) represents a rare and heterogeneous group of malignancies, posing significant challenges in evaluation and management. Surgery, the cornerstone of RPS treatment, critically depends on complete resection for a favorable prognosis. The extent of resection is a crucial determinant of local control and survival. This review delves into the evolution of multidisciplinary management of localized RPS, highlighting the imperative to adapt surgical strategies to tumor histology, location, and patient functional status. We explore the principles of compartmental surgery-an extended first-line approach that involves resecting adjacent viscera for wide negative margins-and its effectiveness across different histological subtypes of RPS and more limited resections for other types. Particular emphasis is placed on the heterogeneity of the disease, as various histological subtypes exhibit distinct biological behaviors. This necessitates a shift away from a one-size-fits-all treatment approach. The review analyzes the role of different surgical strategies, focusing on histological type and location. Additionally, the potential benefits of (neo)adjuvant treatments, such as radiotherapy and chemotherapy, are examined, recognizing their specific histological indications and limitations. This comprehensive review consolidates recent data on surgical strategies and complementary therapies, advocating for a personalized approach tailored to histology. As understanding of the molecular and genetic underpinnings of RPS continues to evolve, so will strategies for its effective management, underscoring the need for global collaboration among specialists in this field to enhance our collective knowledge and treatment methodologies.

3D-SARC: A Pilot Study Testing the Use of a 3D Augmented-Reality Model with Conventional Imaging as a Preoperative Assessment Tool for Surgical Resection of Retroperitoneal Sarcoma

BACKGROUND

Retroperitoneal sarcomas (RPSs) present a surgical challenge, with complex anatomic relationships to organs and vascular structures. This pilot study investigated the role of three-dimensional (3D) augmented reality (3DAR) compared with standard imaging in preoperative planning and resection strategies.

METHODS

For the study, 13 patients who underwent surgical resection of their RPS were selected based on the location of their tumor (right, left, pelvis). From the patients' preoperative computed tomography (CT) scans, 3DAR models were created using a D2P program and projected by an augmented-reality (AR) glass (Hololens). The 3DAR models were evaluated by three experienced sarcoma surgeons and compared with the baseline two-dimensional (2D) contrast-enhanced CT scans.

RESULTS

Three members of the surgical team evaluated 13 models of retroperitoneal sarcomas, resulting in a total of 26 responses. When the surgical team was asked to evaluate whether the 3DAR better prepared the surgeon for planned surgical resection, 10 responses favored the 3DAR, 5 favored the 2D CT scans and 11 showed no difference (p = 0.074). According to 15 (57.6 %) of the 26 responses, the 3DAR offered additional value over standard imaging in the preoperative planning (median score of 4; range, 1-5). The median stated likelihood that the surgeons would consult the 3DAR was 5 (range, 2-5) for the preoperative setting and 3 (range, 1-5) for the intraoperative setting.

CONCLUSIONS

This pilot study suggests that the use of 3DAR may provide additional value over current standard imaging in the preoperative planning for surgical resection of RPS, and the technology merits further study.

The Multimodality Management of Malignant Peripheral Nerve Sheath Tumours

Malignant peripheral nerve sheath tumours (MPNST) are aggressive sarcomas that have nerve sheath differentiation and can present at any anatomical site. They can arise from precursor neurofibroma in the context of neurofibromatosis type 1 (NF1) or as de novo and sporadic tumours in the absence of an underlying genetic predisposition. The primary therapeutic approach is most often radical surgery, with non-surgical modalities playing an important role, especially in locally advanced or metastatic cases. The aim of multimodality approaches is to optimize both local and systemic control while keeping to a minimum acute and late treatment morbidity. Advances in the understanding of the underlying biology of MPNSTs in both sporadic and NF-1-related contexts are essential for the management and implementation of novel therapeutic approaches.

A case report of retroperitoneal liposarcoma

BACKGROUND

Retroperitoneal liposarcoma is a rare and complex tumor originating from the mesenchymal tissues, with no specific manifestations in the early stage, and a large tumor size in the late stage. Patients often consult a physician because of large abdominal mass, increased abdominal circumference, and abdominal pain, and rarely because of leukocytosis.

PATIENT CONCERNS

A 54-year-old female presented to our hospital with complaints of "abdominal distension for over 3 months, left lumbar pain for over 2 months." Considering the comprehensive symptoms, examinations, computed tomography scans, and pathological results, the possibility of retroperitoneal liposarcoma is high.

DIAGNOSES

Retroperitoneal liposarcoma with leukocytosis.

INTERVENTIONS

Open retroperitoneal mass excision along with transcystoscopic left ureteral Double-J Ureterl Stent Insertion tube placement and left nephrectomy.

OUTCOMES

The postoperative pathological findings of the abdominal mass, combined with morphological and immunohistochemical results, are consistent with retroperitoneal liposarcoma. The patient had no recurrence in 7 months of postoperative follow-up conducted on the telephone and is now in continued follow-up.

CONCLUSION

Retroperitoneal liposarcoma is highly malignant and prone to recurrence. Radical surgery is currently the primary treatment modality for patients with this condition. Analogous to cancer patients, those with elevated white blood cell counts and retroperitoneal liposarcoma may have poor prognoses, with a high likelihood of local recurrence and distant metastasis. Close postoperative follow-up is necessary. Therefore, regular postoperative review of blood routine may be a relatively economical and convenient method for the early detection of recurrence and metastasis of retroperitoneal liposarcoma.

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.

Vena cava leiomyosarcoma surgery results in a retrospective cohort of 41 patients from two centers

BACKGROUND

Leiomyosarcoma of the vena cava (LMS-VC) is a rare entity with poor oncological outcomes and a lack of histological staging prognostic factors.

METHODS

Outcomes of consecutive patients operated on LMS-VC between March 2003 and May 2022, in two specialized sarcoma centers were reported.

RESULT

Forty-one patients were identified. Median size of LMS-VC was 9 cm with 68% of complete obstruction. After surgery, severe complication rate was 30%. No postoperative mortality was reported. Microscopic complete excision was obtained for 71% of patients, R1 for 27% and one patient presented an R2 resection. Grade 3 was found in 24%. After a median follow-up of 70 months, 3 years disease-free survival (DFS) and 5 years DFS were 34% and 17%, and 3 years overall survival (OS) and 5 years OS were 74% and 50%. Distant metastasis concerned 54% of recurrences, local 7% and local and distant 5%. Multivariate analysis showed that FNCLCC grade (p < 0.001) and perioperative chemotherapy (p = 0.026) were significant factors for DFS. In multivariate analysis, FNCLCC grade was a significant factor for OS (p = 0.004).

DISCUSSION

Perioperative chemotherapy may have a role to play in lowering the risk of recurrence for LMS-VC, particularly in high-grade tumor.

Clinical features and surgical strategy of retroperitoneal liposarcoma involving the kidney capsule: a retrospective comparative cohort study

BACKGROUND

Valid and generalizable data on the clinical features and surgical strategies for retroperitoneal liposarcoma (LPS) involving the kidney capsule remain scarce. This study aimed to investigate the clinical characteristics, morbidity, mortality, and long-term survival of patients with retroperitoneal LPS involving the kidney capsule.

METHODS

The authors analyzed a prospectively maintained database of patients who underwent surgical resection for retroperitoneal LPS between 2015 and 2020. The patients were categorized into kidney capsule or no kidney capsule groups based on the presence or absence of kidney capsule involvement. A kidney-sparing strategy for retroperitoneal LPS involving the kidney capsule was developed. The primary outcome measure was overall survival (OS). The cumulative event probability curve was estimated using the Kaplan-Meier, and differences between groups using the Log-Rank.

RESULTS

The study population consisted of 128 patients-54 with and 74 without kidney capsule involvement. Of these patients, 70 were female (54.7%) and 58 were male (45.3%), with a median age of 55. The median follow-up duration was 35 months. Postoperative morbidity, mortality, length of hospital stay, length of ICU stay, OS, and recurrence-free survival (RFS) did not differ significantly between the groups. Eleven patients developed postoperative acute kidney injury (AKI), and one patient required dialysis during the follow-up period. In multivariable logistic regression analysis, only nephrectomy was independently associated with postoperative AKI. Subgroup analysis of patients with kidney capsule involvement showed that nephrectomy did not improve OS or RFS but significantly decreased postoperative estimated glomerular filtration rate.

CONCLUSION

Nephrectomy was associated with an increased risk of postoperative AKI after retroperitoneal LPS resection. A kidney-sparing strategy for retroperitoneal LPS involving the kidney capsule achieved optimal clinical outcomes.

Rapidly Progressive High-Grade Leiomyosarcoma in an Elderly Patient

An 84-year-old female with a history of hypertension, diabetes, and hypothyroidism initially presented in November 2023, with a rapidly enlarging (19.5 cm) left proximal thigh mass. Biopsy diagnosed high-grade leiomyosarcoma, which doubled in size within two weeks, confirming aggressive biology. In January 2024, the patient, who had been ambulating independently one year prior to her diagnosis, underwent radical resection and femoral neurolysis, and initiated radiotherapy, without receiving neoadjuvant chemotherapy due to cachexia. Three months postoperatively, in April 2024, the patient presented with acute respiratory distress, requiring 4L oxygen, and bilateral lower extremity edema. Imaging revealed numerous bilateral pulmonary metastases and an acute pulmonary embolism in the right inferior segment branch. She was admitted with decompensated heart failure, an ejection fraction of 30-45%, and extensive metastatic leiomyosarcoma. Despite anticoagulation, her status rapidly declined.  This case highlights the challenges of rapidly progressive sarcomas characterized by fulminant growth and early metastatic spread. Earlier treatment with neoadjuvant chemotherapy prior to surgery may have improved outcomes but was precluded by the patient's frailty. After a multidisciplinary discussion, the decision was made to transition to hospice care. This case also underscores the potential for rapid clinical deterioration with metastatic leiomyosarcoma. It highlights the challenges of managing complications from aggressive malignancies, especially in frail patients, where treatment-related toxicities may outweigh the benefits. Careful patient selection for cancer-directed therapies via multidisciplinary input is imperative.

TRAbectedin in adVanced rEtroperitoneal well differentiated/dedifferentiated Liposarcoma and Leiomyosarcoma (TRAVELL): results of a phase II study from the Italian Sarcoma Group

BACKGROUND

This is a multicentre, single-arm, phase II study aimed at further exploring the activity of trabectedin as second-/further-line treatment in retroperitoneal leiomyosarcoma (LMS) and well-differentiated/dedifferentiated liposarcoma (LPS).

MATERIALS AND METHODS

The primary endpoint was the growth modulation index (GMI) defined as the ratio between PFS under trabectedin (PFS) and during previous chemotherapy treatment: time to progression (TTP-1). Secondary endpoints were objective response rate (ORR) and PFS. As per protocol, patients were considered responders if the GMI was >1.33, non-responders if <0.75 and neither if 0.76-1.32.

RESULTS

Overall 91 patients were assessable for the primary endpoint (32 patients with LMS and 59 patients with LPS): the median number of cycles received was 6.0 (Q1-Q3 3.0-12.0), and the main reason for treatment discontinuation was disease progression in 72% of patients. The median PFS was 6.0 months, while the median TTP1 was 7.5 months (8.1 and 6.4 months for LMS and LPS, respectively). Thirty-three patients [52%, 95% confidence interval (CI) 36% to 58%, P = 0.674, odds of response 1.1] had a GMI >1.33 (LMS 46%, 95% CI 26% to 67%, odds of response 0.85; LPS 56%, 95% CI 40% to 72%, odds of response 1.3). Overall, in LPS we observed 15/47 patients with a GMI <0.5 and 15/47 patients with a GMI >2. Among LMS patients, 9/26 had a GMI <0.5 and 10/26 had a GMI >2. Overall, ORR (complete response + partial response) was 16% (24% for LMS and 12% for LPS).

CONCLUSIONS

While the primary endpoint of the study was not met, we noticed a subgroup of patients with a markedly discrepant TTP with trabectedin in comparison to previous therapy (GMI <0.5 or >2, the latter including some patients with a long TTP with trabectedin). A mismatch between PFS and overall survival was observed, possibly due to the natural history of the two different histologies and the availability of further lines in LMS.

Leiomyosarcoma of the abdomen and retroperitoneum; a systematic review

Background

Intraabdominal and retroperitoneal leiomyosarcomas are rare cancers, which cause significant morbidity and mortality. Symptoms, treatment and follow up differs from other cancers, and proper diagnosis and treatment of intraabdominal and retroperitoneal leiomyosarcomas is of utmost importance. We performed a systematic review to collect and summarize available evidence for diagnosis and treatment for these tumours.

Methods

We performed a systematic literature search of Pubmed from the earliest entry possible, until January 2021. Our search phrase was (((((colon) OR (rectum)) OR (intestine)) OR (abdomen)) OR (retroperitoneum)) AND (leiomyosarcoma). All hits were evaluated by two of the authors.

Results

Our predefined search identified 1983 hits, we selected 218 hits and retrieved full-text copies of these. 144 studies were included in the review.

Discussion

This review summarizes the current knowledge and evidence on non-uterine abdominal and retroperitoneal leiomyosarcomas. The review has revealed a lack of high-quality evidence, and randomized clinical trials. There is a great need for more substantial and high-quality research in the area of leiomyosarcomas of the abdomen and retroperitoneum.

Systematic Review Registration

PROSPERO, identifier, CRD42023480527.

Survival and prognostic factors of primary retroperitoneal sarcomas after surgery: a single-center experience

PURPOSE

The percentage of retroperitoneal sarcomas (RPS) among all soft tissue sarcomas ranges from 10 to 15%. Surgery remains the gold standard for RPS. In this study, we analyzed the impact of surgical treatment for primary RPS on recurrence and overall mortality at a Chinese institution and identified and evaluated prognostic variables.

METHODS

Data from patients with RPS who underwent surgical treatment were retrospectively analyzed. The patients were treated at a single center from January 2000 to June 2018. Retrospectively collected demographic, clinicopathological, and surgical factors were examined. Overall survival (OS) and disease-free survival (DSF) were used as the primary endpoints. Predicted 5-year survival rates, encompassing both DFS and OS, were derived from the Sarculator prognostic nomogram.

RESULTS

A total of 110 patients met the inclusion criteria. The median follow-up time after surgery for patients with primary RPS was 5.3 years. During this period, 59 patients died. The 5-year OS and DFS estimates were 63.5% and 35.3%, respectively. In a multivariate analysis, poor OS following surgical treatment of primary RPS was independently correlated with FNCLCC grade (p < 0.001) and surgical margin status (p = 0.016). FNCLCC grade (p = 0.001) and surgical margin status (p = 0.002) were also independently associated with poor DFS. The C-indices for 5-year OS and DFS survival utilizing the Sarculator prognostic nomogram were 0.71 and 0.73 respectively.

CONCLUSION

The overall mortality rate of patients with RPS was considered acceptable. OS and DFS prognostic markers were established for primary RPS. Tumor grade and intraregional margins are other factors that affect survival and recurrence.

Current unmet needs in locally advanced (unresectable) or metastatic dedifferentiated liposarcoma, the relevance of progression-free survival as clinical endpoint, and expectations for future clinical trial design: an international Delphi consensus report

BACKGROUND

Locally advanced (unresectable) or metastatic dedifferentiated liposarcoma (DDLPS) is a common presentation of liposarcoma. Despite established diagnostic and treatment guidelines for DDLPS, critical clinical gaps remain driven by diagnostic challenges, symptom burden and the lack of targeted, safe and effective treatments. The objective of this study was to gather expert opinions from Europe and the United States on the management, unmet needs and expectations for clinical trial design as well as the value of progression-free survival (PFS) in this disease. Other aims included raising awareness and educate key stakeholders across healthcare systems.

MATERIALS AND METHODS

An international panel of 12 sarcoma key opinion leaders (KOLs) was recruited. The study consisted of two rounds of surveys with pre-defined statements. Experts scored each statement on a 9-point Likert scale. Consensus agreement was defined as ≥75% of experts scoring a statement with ≥7. Revised statements were discussed in a consensus meeting.

RESULTS

Consensus was reached on 43 of 55 pre-defined statements across disease burden, treatment paradigm, unmet needs, value of PFS and its association with overall survival (OS), and cross-over trial design. Twelve statements were deprioritised or merged with other statements. There were no statements where experts disagreed.

CONCLUSION

This study constitutes the first international Delphi panel on DDLPS. It aimed to explore KOL perception of the disease burden and unmet need in DDLPS, the value of PFS, and its potential translation to OS benefit, as well as the relevance of a cross-over trial design for DDLPS therapies. Results indicate an alignment across Europe and the United States regarding DDLPS management, unmet needs, and expectations for clinical trials. Raising awareness of critical clinical gaps in relation to DDLPS can contribute to improving patient outcomes and supporting the development of innovative treatments.

Short- and long-term post-nephrectomy outcomes for retroperitoneal liposarcoma from a high-volume sarcoma center: a propensity score matching analysis

BACKGROUND

Multivisceral en bloc resection with the ipsilateral kidney is commonly performed in patients with retroperitoneal liposarcoma (RLPS). We evaluated the effect of nephrectomy on short- and long-term outcomes in patients with RLPS.

METHODS

Data from a prospectively maintained database of the Peking University Cancer Hospital Sarcoma Center between April 2011 and August 2022 were analyzed. We classified the RLPS patients who underwent surgery into nephrectomy group (NP) and non-nephrectomy group (non-NP). Patients were matched using a 1:1 propensity score to eliminate baseline differences between groups. Postoperative renal function outcomes, major morbidity, and mortality were analyzed to compare short-term outcomes after nephrectomy. Differences in local recurrence-free survival (LRFS) and overall survival (OS) were compared by Kaplan-Meier analysis with respect to oncological benefits.

RESULTS

In the matched cohort, patients in the NP group had significantly higher postoperative eGFR and CKD stages, but none required dialysis. Patients between NP and non-NP had a comparable major morbidity (p = 0.820) and 60-day mortality (p = 0.475). Patients in the NP group had a higher 5-year LRFS rates than those in the non-NP group (34.5 vs. 17.8%, p = 0.015), and similar 5-year OS rates (52.4 vs. 47.1%, p = 0.401). Nephrectomy was an independent risk factor for LRFS, but not for major morbidity or OS.

CONCLUSIONS

RLPS resection with nephrectomy is related to a mild progression of renal impairment; however, dialysis is rare. En bloc nephrectomy for complete resection of RLPS is safe and improves local control.

Sarculator: how to improve further prognostication of all sarcomas

PURPOSE OF REVIEW

Prognostication of soft tissue sarcomas is challenging due to the diversity of prognostic factors, compounded by the rarity of these tumors. Nomograms are useful predictive tools that assess multiple variables simultaneously, providing estimates of individual likelihoods of specific outcomes at defined time points. Although these models show promising predictive ability, their use underscores the need for further methodological refinement to address gaps in prognosis accuracy.

RECENT FINDINGS

Ongoing efforts focus on improving prognostic tools by either enhancing existing models based on established parameters or integrating novel prognostic markers, such as radiomics, genomic, proteomic, and immunologic factors. Artificial intelligence is a new field that is starting to be explored, as it has the capacity to combine and analyze vast and intricate amounts of relevant data, ranging from multiomics information to real-time patient outcomes.

SUMMARY

The integration of these innovative markers and methods could enhance the prognostic ability of nomograms such as Sarculator and ultimately enable more accurate and individualized healthcare. Currently, clinical variables continue to be the most significant and effective factors in terms of predicting outcomes in patients with STS. This review firstly introduces the rationale for developing and employing nomograms such as Sarculator, secondly, reflects on some of the latest and ongoing methodological refinements, and provides future perspectives in the field of prognostication of sarcomas.