Recurrence patterns after resection of retroperitoneal sarcomas: An eight-institution study from the US Sarcoma Collaborative

Case report: Highly response to low-dose brachytherapy in recurrent retroperitoneal leiomyosarcoma with FANCD2 frameshift mutation: a unique case study

We report a case of recurrent retroperitoneal leiomyosarcoma in a male who achieved a rapid and robust but transient clinical response to low-dose iodine-125 brachytherapy. A FANCD2 frameshift mutation was detected by gene sequencing in the cancerous tissue.

A systematic review of the role of chemotherapy in retroperitoneal sarcoma by the Australia and New Zealand sarcoma association clinical practice guidelines working party

BACKGROUND

In primary localised resectable retroperitoneal sarcoma (RPS), loco-regional and distant relapse occur frequently despite optimal surgical management. The role of chemotherapy in improving outcomes is unclear.

METHODS

A systematic review was conducted, using the population, intervention, comparison outcome (PICO) model, to evaluate whether neoadjuvant or adjuvant chemotherapy improve outcomes in adults with primary localised resectable RPS. Medline, Embase and Cochrane Central were queried for publications from 1946 to June 2022 that evaluated recurrence free survival, overall survival, and post operative complications. Each study was screened by two independent reviewers for suitability. A qualitative synthesis of the results was performed.

RESULTS

Twenty three studies were identified; one meta-analysis of retrospective studies and 22 retrospective studies including three with propensity matched cohorts. Most studies did not analyse outcomes by histology, detail treatment regimens, provide baseline characteristics or selection criteria for those receiving chemotherapy. Evidence of selection bias was illustrated in several studies. Newcastle-Ottawa quality of retrospective cohort studies was good for 12 studies and poor for 10 studies. All studies were assessed as Level III-2 evidence by the Australian NHMRC hierarchy. Overall, the addition of neoadjuvant or adjuvant chemotherapy to surgery was not associated with improvement in local recurrence, metastasis free survival, disease free survival or overall survival in primary localised resectable RPS. There is some evidence of an association of chemotherapy with worse overall survival. One single centre study showed that neoadjuvant chemotherapy was not associated with increased post operative complications compared to surgery alone in primary localised resectable RPS.

CONCLUSIONS

There is currently no evidence that demonstrates the addition of chemotherapy to surgery improves outcomes in adult patients with primary localised resectable RPS. Available evidence is limited by its retrospective nature and high likelihood of selection bias with chemotherapy generally administered to patients at higher risk of recurrence and many patients not receiving care in high volume sarcoma centres. Randomised trials are required to conclusively determine the role of chemotherapy in primary localised resectable RPS.

Integrated budget impact model to estimate the impact of introducing selpercatinib as a tumor-agnostic treatment option for patients with RET-altered solid tumors in the US

OBJECTIVE

To estimate the potential budget impact on US third party payers (commercial or Medicare) associated with addition of selpercatinib as a tumor-agnostic treatment for patients with Rearranged during Transfection (RET)-altered solid tumors.

METHODS

An integrated budget impact model (iBIM) with 3-year (Y) time horizon was developed for 19 RET-altered tumors. It is referred to as an integrated model because it is a single model that integrated results across multiple tumor types (as opposed to tumor-specific models developed traditionally). The model estimated eligible patient populations and included tumor-specific comparator treatments for each tumor type. Estimated annual total costs (2022USD, $) included costs of drug, administration, supportive care, and toxicity. For a one-million-member plan, the number of patients with RET-altered tumors eligible for treatment, incremental total costs, and incremental per-member per-month (PMPM) costs associated with introduction of selpercatinib treatment were estimated. Uncertainty associated with model parameters was assessed using various sensitivity analyses.

RESULTS

Commercial perspective estimated 11.68 patients/million with RET-altered tumors as treatment-eligible annually, of which 7.59 (Y1), 8.17 (Y2), and 8.76 (Y3) patients would be selpercatinib-treated (based on forecasted market share). The associated incremental total and PMPM costs (commercial) were estimated to be: $873,099 and $0.073 (Y1), $2,160,525 and $0.180 (Y2), and $2,561,281 and $0.213 (Y3), respectively. The Medicare perspective estimated 55.82 patients/million with RET-altered tumors as treatment-eligible annually, of which 36.29 (Y1), 39.08 (Y2), and 41.87 (Y3) patients would be selpercatinib-treated. The associated incremental total and PMPM costs (Medicare) were estimated to be: $4,447,832 and $0.371 (Y1), $11,076,422 and $0.923 (Y2), and $12,637,458 and $1.053 (Y3), respectively. One-way sensitivity analyses across both perspectives identified drug costs, selpercatinib market share, incidence of RET, and treatment duration as significant drivers of incremental costs.

CONCLUSIONS

Three-year incremental PMPM cost estimates suggest a modest impact on payer-budgets associated with introduction of tumor-agnostic selpercatinib treatment.

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.

Clinician survey of current global practice for sarcoma surveillance following resection of primary retroperitoneal, abdominal, and pelvic sarcoma

INTRODUCTION

- Postoperative surveillance following resection of primary retroperitoneal, abdominal, and pelvic sarcoma (RPS) is standard of care in international sarcoma centres and has rapidly evolved without an evidence base to become highly intensive and prolonged. This clinician survey aims to capture a global, contemporary snapshot of international guidelines used to inform sarcoma surveillance following resection of primary RPS.

MATERIALS AND METHODS

- Between July 2022 and March 2023, an online, anonymous, clinician survey to assess the current duration, imaging intervals and imaging modalities used for postoperative surveillance following resection of primary RPS was distributed among clinicians working at centres which are members of the TransAtlantic Australasian Retroperitoneal Working Group (TARPSWG).

RESULTS

- Responses were received from 58 different TARPSWG centres. The majority of centres use institutional guidelines to guide surveillance intensity (n = 43, 74%) and the surveillance imaging modality (n = 39, 67%) used. For surveillance intensity and imaging modality, institutional guidelines are partially or entirely based on international guidelines in 81% (n = 47) and 78% (n = 45) of centres, respectively. Commonly used imaging modalities are contrast-enhanced CT abdomen-pelvis (n = 51, 88%) for abdominal surveillance and non-contrast enhanced CT (n = 25, 43%) for chest surveillance. Imaging intervals, timing of de-escalation of imaging frequency and total duration of surveillance for low-grade and high-grade RPS are reported.

CONCLUSION

- This global survey among TARPSWG members demonstrates the heterogeneity in sarcoma surveillance strategies worldwide and emphasises the need for a randomised controlled trial to provide an evidence base for the optimal surveillance schedule following primary resection of RPS.

Patient-Derived Organoids as a Promising Tool for Multimodal Management of Sarcomas

The management of sarcomas, a diverse group of cancers arising from connective tissues, presents significant challenges due to their heterogeneity and limited treatment options. Patient-derived sarcoma organoids (PDSOs) have emerged as a promising tool in the multimodal management of sarcomas, offering unprecedented opportunities for personalized medicine and improved treatment strategies. This review aims to explore the potential of PDSOs as a promising tool for multimodal management of sarcomas. We discuss the establishment and characterization of PDSOs, which realistically recapitulate the complexity and heterogeneity of the original tumor, providing a platform for genetic and molecular fidelity, histological resemblance, and functional characterization. Additionally, we discuss the applications of PDSOs in pathological and genetic evaluation, treatment screening and development, and personalized multimodal management. One significant advancement of PDSOs lies in their ability to guide personalized treatment decisions, enabling clinicians to assess the response and efficacy of different therapies in a patient-specific manner. Through continued research and development, PDSOs hold the potential to revolutionize sarcoma management and drive advancements in personalized medicine, biomarker discovery, preclinical modeling, and therapy optimization. The integration of PDSOs into clinical practice can ultimately improve patient outcomes and significantly impact the field of sarcoma treatment.

Primary Bladder Sarcoma: A multi-institutional experience from the Rare Cancer Network

PURPOSE OR OBJECTIVE

Primary sarcoma of the urinary bladder (SUB) is a rare but aggressive form of bladder cancer (BCa). Available evidence on SUB is limited to case reports and small series. The aim of the present multi-institutional study was to assess the clinical features, treatments, and outcomes of patients with SUB.

MATERIALS AND METHODS

Using a standardized database, 7 institutions retrospectively collected the demographics, risk factors, clinical presentation, treatment modalities and follow-up data on patients with SUB between January 1994 and September 2021. The main inclusion criteria included BCa with soft tissue tumor histology and sarcomatoid differentiation.

RESULTS

Fifty-three patients (38 men and 15 women) were identified. Median follow-up was 18 months (range 1-263 months). Median age at presentation was 69 years (range 16-89 years). Twenty-six percent of patients had a prior history of pelvic radiotherapy (RT), and 37% were previous smokers. The main presenting symptoms at diagnosis were hematuria (52%), pelvic pain (27%), and both hematuria and pelvic pain (10%). American Joint Committee on Cancer (AJCC) 8 th edition stage II, III and IV at diagnosis were 21%, 63% and 16%, respectively. Treatment modalities included surgery alone (45%), surgery plus neo- or adjuvant-chemotherapy (17%), surgery plus neo- or adjuvant-RT (11%), RT with concurrent chemotherapy (4%), neo-adjuvant chemotherapy plus surgery plus adjuvant RT (2%) and palliative treatment (21%). Rates of local and distant recurrences were 49% and 37%, respectively. Five-year overall survival and progression-free survival (PFS) were 66.5% and 37.6%, respectively. No statistically significant differences in PFS between the treatment modalities were observed.

CONCLUSIONS

Primary SUB is a heterogeneous disease group, commonly presenting at advanced stages and exhibiting aggressive disease evolution. In contrast to urothelial carcinoma, the primary pattern of recurrence of SUB is local, suggesting the need for multimodal approaches. Continuous international collaborative efforts seem warranted to provide guidance on how to best tailor treatments based on SUB-specific indices.

Follow-up of patients with retroperitoneal sarcoma

Retroperitoneal sarcomas (RPS) are rare malignancies that are potentially curable by complete surgical resection. A regular surveillance program is normally commenced following surgery due to the risk of local recurrence (LR), especially in low-intermediate grade disease, and distant metastases (DM), especially in high-grade RPS. Consensus guidelines usually advocate for more frequent imaging during the first 2-3 years and less intensive imaging over a prolonged period thereafter, reflecting the incidence pattern of LR and DM. Definitive evidence for the most effective imaging schedule has never been provided, and retrospective studies have not shown an association between follow-up intensity and survival. Improvement in the prediction of recurrence patterns has been sustained by prognostic dynamic nomograms, which are now capable of forecasting disease behaviour in each patient according to specific features. Incorporation of such tools in clinical practice may help to stratify patients and tailor ongoing surveillance to the risk of recurrence. This may help to relieve patients' anxiety while awaiting results of surveillance investigations, and also reduce the economic and environmental burden of repeated imaging. A randomized controlled study (SARveillance Trial) is proposed to shed light on this controversial topic, allowing clinicians to harmonize the follow-up protocol of patients undergoing surgery for RPS.

Management of recurrent retroperitoneal sarcomas

Recurrent retroperitoneal sarcomas are rare, with patterns of recurrence determined by the histologic subtype. A range of patient characteristics and treatment profiles combined with a myriad of presentations and clinical courses of recurrences make this diverse entity challenging to manage. Although surgical resection improves survival in select patients, the oncological outcomes are inferior to that of primary retroperitoneal sarcomas. Management options for unresectable disease include local ablative therapy, radiation and systemic therapy, with palliative surgery indicated occasionally. Attempts at disease control must be balanced with potential morbidity and impact on the patient's quality of life. This review aims to offer insights into the current understanding of recurrent retroperitoneal sarcomas and provide some guidance on management.

Experiences of patients and their relatives of postoperative radiological surveillance and surveillance intensity following primary resection of a soft tissue sarcoma and its impact on their quality of life: a systematic review protocol

INTRODUCTION

Postoperative radiological surveillance following primary resection of a soft tissue sarcoma (sarcoma of the retroperitoneum, abdomen, pelvis, trunk or extremities) is standard of care in all international high-volume sarcoma centres in the world. The intensity of postoperative surveillance imaging is highly varied and knowledge of the impact of surveillance and surveillance intensity on patients' quality of life is limited. The aim of this systematic review is to summarise the experiences of patients and their relatives/caregivers of postoperative radiological surveillance following resection of a primary soft tissue sarcoma and its impact on their quality of life.

METHODS AND ANALYSIS

We will systematically search MEDLINE, EMBASE, PsycINFO, CINAHL Plus and Epistemonikos. Hand searching of reference lists of included studies will be conducted. Further searches will be performed via Google Scholar, to reveal further studies within unpublished 'grey' literature. Two reviewers will independently screen the titles and abstracts following the eligibility criteria. After retrieval of the full text of the selected studies, the methodological quality will be appraised using the Joanna Briggs Institute Critical Appraisal Checklist for Qualitative Research and the Center for Evidence-Based Management checklist for Critical Appraisal of a Cross-Sectional Study. Data on the study population, relevant themes and conclusions will be extracted from the selected papers, and a narrative synthesis will be conducted.

ETHICS AND DISSEMINATION

The systematic review does not require ethics approval. The findings of the proposed work will be published in a peer-reviewed journal and disseminated widely to patients, clinicians and allied health professionals through the Sarcoma UK website, the Sarcoma Patient Advocacy Global Network and the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group. In addition, the outcomes of this research will be presented at national and international conferences.

PROSPERO REGISTRATION NUMBER

CRD42022375118.

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.

Surveillance Post Surgery for Retroperitoneal Soft Tissue Sarcoma

Complete en bloc surgical resection offers the best opportunity for the cure of primary retroperitoneal sarcomas (RPS). The potential for disease recurrence, in the form of both loco-regional recurrence and distant metastases, underpins the rationale for postoperative surveillance. There is a paucity of high-quality evidence underpinning follow-up for RPS patients, and most practice guidelines draw from expert opinion and evidence from soft tissue sarcomas of the extremities. The available observational retrospective data analysis has failed to demonstrate that high-intensity radiological surveillance improves the overall survival in patients. The lack of a robust evidence base has given rise to variations in approaches to post-operative surveillance strategies adopted by specialist centres managing RPS across the world. More high-quality prospective research is needed and planned to more clearly support surveillance approaches that balance oncologic outcomes, patient-centric care, and health service value. Risk stratification tools exist and are available for use in routine practice. Their use will likely support more individualised post-operative surveillance moving forward. Surveillance will likely be underpinned by serial radiological imaging for the medium term. However, developments in genomics offer hope for biomarkers such as ctDNA to impact patient care positively in the future and further support individualised patient care pathways.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Retroperitoneal Sarcomas: Histology Is Everything

Retroperitoneal sarcomas (RPS) are a rare subset of soft tissue sarcoma that are composed of only a few histologic subtypes, each with a distinct tumor biology, clinical presentation, preferred treatment strategy, recurrence risk, and surveillance plan. In the modern era of precision medicine, our understanding of the implications of subtype tumor biology and anatomic location has led to a more nuanced, histology-specific approach to therapy, including surgery, neoadjuvant radiation therapy, and/or chemotherapy. This article provides a summary of recent updates to the management of RPS.

Patient-Specific Sarcoma Organoids for Personalized Translational Research: Unification of the Operating Room with Rare Cancer Research and Clinical Implications

INTRODUCTION

Sarcoma clinical outcomes have been stagnant for decades due to heterogeneity of primaries, lack of comprehensive preclinical models, and rarity of disease. We hypothesized that engineering hydrogel-based sarcoma organoids directly from the patient without xenogeneic extracellular matrices (ECMs) or growth factors is routinely feasible and allows rare tumors to remain viable as avatars for personalized research.

METHODS

Surgically resected sarcomas (angiosarcomas, leiomyosarcoma, gastrointestinal stromal tumor, liposarcoma, myxofibrosarcoma, dermatofibrosarcoma protuberans [DFSP], and pleiomorphic abdominal sarcoma) were dissociated and incorporated into a hyaluronic acid and collagen-based ECM hydrogel and screened for chemotherapy efficacy. A subset of organoids was enriched with a patient-matched immune system for screening of immunotherapy efficacy (iPTOs). Response to treatment was assessed using LIVE/DEAD staining and metabolic assays.

RESULTS

Sixteen sarcomas were biofabricated into three-dimensional (3D) patient-specific sarcoma organoids with a 100% success rate. Average time from organoid development to initiation of drug testing was 7 days. Enrichment of organoids with immune system components derived from either peripheral blood mononuclear cells or lymph node cells was performed in 10/16 (62.5%) patients; 4/12 (33%) organoids did not respond to chemotherapy, while response to immunotherapy was observed in 2/10 (20%) iPTOs.

CONCLUSIONS

A large subset of sarcoma organoids does not exhibit response to chemotherapy or immunotherapy, as currently seen in clinical practice. Routine development of sarcoma hydrogel-based organoids directly from the operating room is a feasible platform, allowing for such rare tumors to remain viable for personalized translational research.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Analysis of the Effect of Tumor-Grade Change on the Prognosis of Retroperitoneal Sarcoma

Simple Summary

Changes in tumor differentiation have been observed during local recurrence in retroperitoneal sarcoma (RPS), and these changes have been reported to affect prognosis. However, the change in the tumor grade from the primary tumor to the first local recurrence, and the effect of this change on long-term outcomes, are unknown. This study reports the presence of tumor-grade changes and their effect on patient prognosis. While the grade changes did not affect the patient’s prognosis, a high grade of the primary tumor was an important factor. In addition, the risk factor for second local recurrence was a high grade of the recurrent tumor. Although this finding cannot change the treatment plan for recurrent RPS, it can provide the details of nomograms to predict the patient prognosis.

Abstract

In retroperitoneal sarcoma (RPS), the change in the tumor grade from the primary tumor to the first local recurrence, and the effect of this change on prognosis, are unknown. The aim of this study is to analyze whether these changes affect the prognosis of RPS. Patients who underwent surgery for a first locally recurrent RPS at Samsung Medical Center from January 2001 to February 2020 were included. The pathologic features of primary and recurrent tumors were compared, and the outcomes were measured. A total of 49 patients were investigated. There were 25 patients with different grades of primary and recurrent tumors. The improving, stable, and worsening groups contained 16 (32.7%), 24 (49%), and 9 (18.3%) patients, respectively. There was no significant difference in the prognosis between the three groups. In the analyses of the factors that affect the OS, a high grade of the primary tumor (p = 0.023) and the size of the recurrent tumor (p = 0.032) were statistically significant in both univariate and multivariate analyses. In a factor analysis of the second LR, a high-grade recurrent tumor (p = 0.032) was the only significant factor. There were tumor-grade changes between the primary tumor and recurrent tumor in RPS. However, the most important factor in prognosis is a high grade of the primary tumor.

Critical impact of radiotherapy protocol compliance and quality in the treatment of retroperitoneal sarcomas: Results from the EORTC 62092-22092 STRASS trial

BACKGROUND

The European Organization for Research and Treatment of Cancer 22092-62092 STRASS trial failed to demonstrate the superiority of neoadjuvant radiotherapy (RT) over surgery alone in patients with retroperitoneal sarcoma. Therefore, an RT quality-assurance program was added to the study protocol to detect and correct RT deviations. The authors report results from the trial RT quality-assurance program and its potential effect on patient outcomes.

METHODS

To evaluate the effect of RT compliance on survival outcomes, a composite end point was created. It combined the information related to planning target volume coverage, target delineation, total dose received, and overall treatment time into 2 groups: non-RT-compliant (NRC) for patients who had unacceptable deviation(s) in any of the previous categories and RT-compliant (RC) otherwise. Abdominal recurrence-free survival (ARFS) and overall survival were compared between the 2 groups using a Cox proportional hazard model adjusted for known prognostic factors.

RESULTS

Thirty-six of 125 patients (28.8%) were classified as NRC, and the remaining 89 patients (71.2%) were classified as RC. The 3-year ARFS rate was 66.8% (95% confidence interval [CI], 55.8%-75.7%) and 49.8% (95% CI, 32.7%-64.8%) for the RC and NRC groups, respectively (adjusted hazard ratio, 2.32; 95% CI, 1.25-4.32; P = .008). Local recurrence after macroscopic complete resection occurred in 13 of 89 patients (14.6%) versus 2 of 36 patients (5.6%) in the RC and NRC groups, respectively.

CONCLUSIONS

The current analysis suggests a significant benefit in terms of ARFS in favor of the RC group. This association did not translate into less local relapses after complete resection in the RC group. Multidisciplinary collaboration and review of cases are critical to avoid geographic misses, especially for rare tumors like retroperitoneal sarcoma.

Factors associated with disease-free and abdominal recurrence-free survival in abdominopelvic and retroperitoneal sarcomas

Background and Objectives

Retroperitoneal and abdominopelvic sarcomas are rare heterogeneous malignancies. The only therapy proven to improve disease‐free survival (DFS) is R0/R1 surgical resection. We sought to analyze whether additional factors such as radiation and systemic therapy were associated with DFS and abdominal recurrence‐free survival (RFS).

Methods

Retrospective review of adults (≥18) with resectable abdominopelvic and retroperitoneal sarcomas who underwent intent‐to‐cure surgery at a high‐volume tertiary referral center between 1998 and 2015. The main outcome measures were DFS and abdominal RFS.

Results

Overall, 159 patients met the criteria for inclusion. Median follow‐up was 4.8 years (range 0.1–18.9 years). The most common histology was liposarcoma (49%). Systemic therapy was administered to 48% of patients and was not associated with improved outcomes. The neoadjuvant radiotherapy group (11%) had improved adjusted DFS (5.46 years, 95% CI [3.68, 7.24] vs. 3.1 years, 95% CI [2.48, 3.73]) and abdominal RFS (6.14 years, 95% CI [4.38, 7.89] vs. 3.22 years, 95% CI [2.61, 3.84]). The adjuvant radiotherapy group (19%) had no improvement.

Conclusions

In a cohort of patients undergoing resection for retroperitoneal or abdominopelvic sarcoma, neoadjuvant radiation improved DFS and abdominal RFS. A follow‐up of over three years was needed to appreciate a difference in outcomes.

A long-term survivor of advanced retroperitoneal dedifferentiated liposarcoma: a successful multimodal approach with extended resection and chemotherapy

Surgical resection is the mainstay of treatment for retroperitoneal liposarcoma (RPLS). Herein, we describe a case of dedifferentiated RPLS successfully treated with an extended surgical approach with adjuvant chemotherapy. A 61-year-old male was referred to our hospital with a chief complaint of chest tightness. Abdominal computed tomography revealed a large retroperitoneal tumor, 11 cm in diameter, extensively invading the surrounding organs: the celiac axis, the splenic artery, the pancreatic body and tail, the lesser curvature of the stomach and the left adrenal gland. Endoscopic ultrasound-guided fine-needle aspiration biopsy confirmed dedifferentiated liposarcoma, suggesting aggressive tumor biology. We performed total gastrectomy combined with distal pancreatectomy with celiac axis and left adrenal gland resection with a curative intent. The postoperative course was almost uneventful. As the pathological findings indicated a positive margin with a well-differentiated liposarcoma component, we added adjuvant chemotherapy with four cycles of doxorubicin and ifosfamide (AI). Five years after primary surgery, regular follow-up CT demonstrated a pulmonary hilar lymph node enlargement and a tumor at paraesophageal locations. After downsizing chemotherapy with eribulin followed by pazopanib, he underwent partial esophagectomy with dissection of the paraesophageal tumor. The pathological findings indicated recurrence of dedifferentiated liposarcoma with a tumor-free surgical margin. He is currently alive without any evidence of recurrence almost 7 years after the first surgery and 15 months after the second surgery. The long-term survival gained in this patient indicates that extended resections and adjuvant chemotherapy could prolong survival in patients even with RPLS with dedifferentiated tumor histology.

Post-Systemic Chemotherapy Prognoses of Recurrent/Metastatic Soft Tissue Sarcoma Patients with Retroperitoneal/Intra-Abdominal Origin vs. Those with Extremities/Trunk Origin

BACKGROUND

The clinical benefit of systemic chemotherapy for recurrent/metastatic retroperitoneal/intra-abdominal soft tissue sarcoma (STS) compared to its benefits for other primary lesions has not been known or sufficiently evaluated.

METHODS AND PATIENTS

We retrospectively reviewed the cases of the STS patients who consulted a department of medical oncology in Tokyo between June 2011 and March 2018, and we extracted the cases of patients with primary sites at the retroperitoneum/intra-abdomen (cohort R) or extremities/trunk (cohort E) who received systemic chemotherapy in a recurrent/metastatic setting, comparing the cohorts' characteristics, chemotherapy details, and prognoses.

RESULTS

Of all 337 STS patients, we enrolled 49 patients in cohort R and 75 patients in cohort E. Liposarcoma was more frequently observed in cohort R (51.0%) than cohort E (22.7%). The median chemotherapy treatment line was two lines (range: 1-6) in cohort R and three lines (range: 1-9) in cohort E. The doxorubicin usage rates differed in recurrent/metastatic settings (90.0% in cohort R and 55.0% in cohort E), due mainly to the higher rate of a perioperative chemotherapy treatment history in cohort E (52.0% vs. 6.1% in cohort R). The median overall survival from the start of salvage chemotherapy was 31.9 months (cohort R; 95%CI: 20.9-42.8) and 27.1 months (cohort E; 95%CI: 21.6-32.5) (p=0.549).

CONCLUSION

There were differences in the distributions of pathology and antitumor drugs used in a salvage setting between retroperitoneal/intra-abdominal and extremities/trunk STS patients in recurrent/metastatic settings, but the prognoses with salvage chemotherapy were similar in the two cohorts.

Comparison of preoperative chemoradiation with radiation or chemotherapy alone in patients with non-metastatic, resectable retroperitoneal sarcoma

Aim:

Optimal preoperative therapy regimen in the treatment of resectable retroperitoneal sarcoma (RPS) remains unclear. This study compares the impact of preoperative radiation, chemoradiation and chemotherapy on overall survival (OS) in RPS patients.

Materials and Methods:

The National Cancer Database (NCDB) was queried for patients with non-metastatic, resectable RPS (2006–15). The primary endpoint was OS, evaluated by Kaplan–Meier method, log-rank test, Cox multivariable analysis and propensity score matching.

Results:

A total of 1,253 patients met the inclusion criteria, with 210 patients (17%) receiving chemoradiation, 850 patients (68%) receiving radiation and 193 patients (15%) receiving chemotherapy. On Cox multivariable analysis, when compared to preoperative chemoradiation, preoperative radiation was not associated with improved OS (hazards ratio [HR] 0·98, 95% CI 0·76–1·25, p = 0·84), while preoperative chemotherapy was associated with worse OS (HR 1·64, 95% CI 1·24–2·18, p < 0·001). Similar findings were observed in 199 and 128 matched pairs for preoperative radiation and chemotherapy, respectively, when compared to preoperative chemoradiation.

Findings:

Our study suggested an OS benefit in using preoperative chemoradiation compared to chemotherapy alone, but OS outcomes were comparable between preoperative chemoradiation and radiation alone.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Long-term survival by repeat resection for metastases from primary retroperitoneal leiomyosarcoma: A case report

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Retroperitoneal (RP) leiomyosarcoma (LMS) is rare, with a high recurrence rate.

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A woman with RP LMS underwent over 20 surgeries for recurrence over 24 years.

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Long-term survival of 29 years was achieved after these resections.

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Aggressive and radical repeat resections may be beneficial in such patients.

Backgound

Retroperitoneal (RP) leiomyosarcoma (LMS) is a rare type of cancer, accounting for 0.1% of all malignancies. The gold-standard treatment for sarcoma is complete resection, and a 50% 5-year overall survival (OS) rate can be achieved by curative surgery. The survival benefits of radiotherapy and systemic chemotherapy for recurrence are not as good as those of surgical resection. To the best of our knowledge, there are a few reports that aggressive radical surgery significantly prolonged the survival period as our case. This case was reported in accordance with the SCARE 2020 Guideline (Ref).

Case presentation

An 84-year-old woman was referred to our hospital for treatment of a primary RP tumour. At the age of 52-year-old, she underwent complete resection of an RP mass in 1991. Twenty-four years after the primary resection, metachronous recurrences occurred within the soft tissues, which were repeatedly resected. From 2015–2019, liver resections were performed thrice, and the patient survived with no signs of recurrence 1 year after the last surgery.

Conclusion

Long-term survival of 29 years was achieved after undergoing over 20 surgical resections. Herein, we report the long-term survival of a patient who underwent repeated aggressive surgical resections for RP LMS recurrence anda literature review.

The importance of the margin of resection and external radiation in non-lipomatous retroperitoneal sarcoma

BACKGROUND

Prior studies evaluating the impact of adjuvant or neoadjuvant radiation on clinical outcomes of patients with non-lipomatous retroperitoneal sarcoma have been underpowered.

METHODS

We queried the National Cancer Database to identify patients undergoing surgical resection of retroperitoneal sarcoma with non-lipomatous histology from 2004 to 2016. Multivariable logistic regression and Cox proportional hazards modelling with patients stratified by tumor size were used to identify factors associated with overall survival.

RESULTS

3,394 patients met inclusion criteria. 592 had small (<5 cm), 1,186 had intermediate (5-10 cm), and 1,616 had large (>10 cm) tumors. Use of either neoadjuvant or adjuvant radiotherapy was associated with improved survival for patients with intermediate (neoadjuvant HR 0.67, CI [0.46, 0.98]; adjuvant HR 0.61, CI [0.50, 0.76]) and large (neoadjuvant HR 0.50, CI [0.37, 0.68]; adjuvant HR 0.56, CI [0.47, 0.69]) tumors, while adjuvant radiation therapy was associated with a survival benefit for small-sized tumors (HR 0.67, CI [0.46, 0.99]).

CONCLUSIONS

Radiation therapy is associated with an overall survival benefit in patients presenting undergoing resection of non-lipomatous retroperitoneal sarcoma.

Single centre 30-year experience in treating retroperitoneal liposarcomas

BACKGROUND AND OBJECTIVES

Liposarcomas form a diverse group of tumors that represent the majority of retroperitoneal soft tissue sarcomas. Radical excision of these retroperitoneal liposarcomas is often challenging due to their large size and proximity to visceral organs and major vessels. Here we present the 30-year experience of our multidisciplinary sarcoma team in the treatment of these tumors and analysis of factors influencing survival.

METHODS

Patients with retroperitoneal liposarcomas treated in Helsinki University Hospital from 1987 to 2017 were reviewed. Local recurrence-free survival, metastases-free survival, and disease-specific survival were assessed with Kaplan-Meier analysis, and factors influencing survival were evaluated with Cox regression.

RESULTS

A total of 107 patients were identified. The median follow-up time was 5.4 years (interquartile range: 2.2-8.8 years). Local recurrence developed in 72% and metastases in 15% during follow-up. The 5-year disease-free survival was 31% and disease-specific survival was 66%. The multifactorial analysis revealed histological type and grade as predictors of disease-specific survival (P < .01) while multifocality carried a poor prognosis for local recurrence (P = .02) and higher histological grade for metastases (P < .01).

CONCLUSIONS

Retroperitoneal liposarcomas rarely metastasize but tend to recur locally. For tumors that have been resected with macroscopically clear margins, histological, type, and grade are significant predictors of survival.