Management of recurrent retroperitoneal sarcoma

Retroperitoneal Soft Tissue Sarcoma: Emerging Therapeutic Strategies

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

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.

Next questions in the management of retroperitoneal sarcoma

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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.

Complex Vascular Resections for Retroperitoneal Soft Tissue Sarcoma

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

Short- and long-term surgical outcomes of pancreatic resection for retroperitoneal sarcoma: A long-term single-center experience of 90 cases

BACKGROUND AND OBJECTIVES

Resection of retroperitoneal sarcoma (RPS) en bloc with pancreas is challenging and controversial. This single-center retrospective study aimed to analyze the impact of pancreatic resection (PR) and its different types on short- and long-term outcomes in patients with RPS.

METHODS

Data from 242 consecutive patients with RPS who underwent surgical treatment at the Peking University Cancer Hospital Sarcoma Center between January 2010 and February 2021 were analyzed. Out of these, 90 patients underwent PR, including pancreaticoduodenectomy (PD) in 31 and distal pancreatectomy (DP) in 59.

RESULTS

Patients in the PR group had a higher major morbidity (37.8% vs. 14.5%) and mortality (8.9% vs. 1.3%) than those in the non-PR group, with a similar 5-year overall survival (OS) rate (46.9% vs. 53.6%). Patients in the PD and DP groups had a slight difference in major morbidity (48.4% vs. 32.2%), mortality (6.4% vs. 10.2%), and 5-year OS rates (43.3% vs. 49.3%). The PR type was not an independent risk factor for major morbidity or OS.

CONCLUSIONS

PR in RPS resection was associated with increased morbidity and mortality with minimal influence on survival. Patients with RPS undergoing PD and DP showed slight differences in terms of safety and OS.

Management of pelvic sarcoma

Pelvic sarcomas are a rare and heterogenous group of tumors divided into two groups: soft tissue sarcomas and bone sarcomas. Soft tissue sarcomas of the pelvis include most commonly liposarcoma, leiomyosarcoma, gastrointestinal stromal tumors, malignant peripheral nerve sheath tumors, and solitary fibrous tumors. Bone sarcomas of the pelvis most commonly include osteosarcoma and chondrosarcoma. Multidisciplinary treatment at a center experienced in the treatment of sarcoma is essential. Management is dictated by histologic type and grade. Surgical resection with wide margins is the cornerstone of treatment for pelvic sarcomas, although this is often challenging due to anatomic constraints of the pelvis. Multimodal treatment is critical due to the high risk of local recurrence in the pelvis.

Patients with first recurrent retroperitoneal sarcoma that can be macroscopically completely resected can achieve comparable outcomes with that of primary patients after en bloc resection of tumor and adjacent organs

The outcomes of patients with primary retroperitoneal sarcoma (RPS) are significantly superior to those with recurrence. En bloc resection of tumor and adjacent organs is recommended in primary RPS. However, whether en bloc resection of tumor and adjacent organs can benefit recurrent patients or some recurrent patients is unclear. We compared the outcomes of patients with primary RPS, first recurrence (RPS-Rec1), and ≥2 recurrences (≥RPS-Rec2) to evaluate the value and criteria for en bloc resection of tumor and adjacent organs in recurrent cases. We evaluated the safety of en bloc resection of tumor and adjacent organs by assessing operation time, blood loss volume, postoperative morbidities (POM), and efficacy by comparing local recurrence and peritoneal metastasis (LR-PM), distant metastasis, progression-free survival (PFS), and overall survival (OS). A total of 101, 47, and 30 patients with primary RPS, RPS-Rec1, and ≥RPS-Rec2 were included, respectively. Recurrent RPS invaded more adjacent organs and surrounding fat tissue than primary RPS. The operation time, amount of blood loss, incidence of grade III–V POM, LR-PM rate, PFS, and OS in the RPS-Rec1 group were similar to those of the primary group, both of which were significantly superior to those of the ≥RPS-Rec2 group. Macroscopically incomplete resection and high-grade RPS rather than first recurrence were independent risk factors for LR-PM, PFS, and OS. In conclusion, the safety and efficacy of en bloc resection of tumor and adjacent organs in RPS-Rec1 were comparable with those in primary RPS but significantly superior to those of ≥RPS-Rec2. For RPS-Rec1, comparable outcomes to patients with primary RPS can be achieved, particularly in those in whom a macroscopically complete resection is achieved.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Retroperitoneal 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.

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.

Prognostic Factors and Nomogram Construction for First Local Recurrent Retroperitoneal Sarcoma Following Surgical Resection: A Single Asian Cohort of 169 Cases

Objective

This study aimed to explore the prognostic factors for first local recurrent retroperitoneal soft tissue sarcoma (FLR-RPS) and construct predictive nomograms in the Asian population.

Methods

In a single Asian sarcoma center, data of patients with FLR-RPS were retrospectively analyzed from January 2011 to September 2020. We developed and internally validated prognostic factors determined by the Cox regression model, as well as nomograms for predicting recurrence-free survival (RFS) and overall survival (OS). The concordance index and calibration curve were used to determine the nomogram’s discriminative and predictive ability.

Results

With 169 patients, the median follow-up duration was 48 months and the 5-year OS rate was 60.9% (95% confidence interval (CI), 51.9%–69.9%). OS was correlated with chemotherapy at the time of initial surgery and tumor grading. The 5-year cumulative local recurrence rate and distant metastasis rate were 75.9% (95% CI, 67.5%–84.3%) and 10.1% (95% CI, 4.2%–16.0%), respectively, and the length of the disease-free interval following the primary operation was associated with disease recurrence. The 6-year OS and cumulative recurrence rate after surgery in our cohort were comparable with those in the TARPSWG cohort, but the proportion of local recurrence was higher (80.4% vs. 59.0%), and distant metastasis was less common (10.1% vs. 14.6%). In this study, two nomogram prediction models were established, which could predict the 1-, 2-, and 5-year OS and RFS, and the concordance indices were 0.74 and 0.70, respectively. The calibration plots were excellent.

Conclusions

For the FLR-RPS patients, some can still achieve an ideal prognosis. The treatment of FLR-RPS in Asian populations can be aided by the predictive model established in this study.

Retroperitoneal Sarcoma Care in 2021

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

Outcome after surgical resection of multiple recurrent retroperitoneal soft tissue sarcoma

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Postoperative Morbidity After Resection of Recurrent Retroperitoneal Sarcoma: A Report from the Transatlantic Australasian RPS Working Group (TARPSWG)

BACKGROUND

This study aimed to evaluate perioperative morbidity after surgery for first locally recurrent (LR1) retroperitoneal sarcoma (RPS). Data concerning the safety of resecting recurrent RPS are lacking.

METHODS

Data were collected on all patients undergoing resection of RPS-LR1 at 22 Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) centers from 2002 to 2011. Uni- and multivariable logistic models were fitted to study the association between major (Clavien-Dindo grade ≥ 3) complications and patient/surgery characteristics as well as outcome. The resected organ score, a method of standardizing the number of organs resected, as previously described by the TARPSWG, was used.

RESULTS

The 681 patients in this study had a median age of 59 years, and 51.8% were female. The most common histologic subtype was de-differentiated liposarcoma (43%), the median resected organ score was 1, and 83.3% of the patients achieved an R0 or R1 resection. Major complications occurred for 16% of the patients, and the 90-day mortality rate was 0.4%. In the multivariable analysis, a transfusion requirement was found to be a significant predictor of major complications (p < 0.001) and worse overall survival (OS) (p = 0.010). However, having a major complication was not associated with a worse OS or a higher incidence of local recurrence or distant metastasis.

CONCLUSIONS

A surgical approach to recurrent RPS is relatively safe and comparable with primary RPS in terms of complications and postoperative mortality when performed at specialized sarcoma centers. Because alternative effective therapies still are lacking, when indicated, resection of a recurrent RPS is a reasonable option. Every effort should be made to minimize the need for blood transfusions.

A novel nomogram for predicting local recurrence-free survival after surgical resection for retroperitoneal liposarcoma from a Chinese tertiary cancer center

BACKGROUND

Local recurrence is the most difficult postoperative challenge and the leading cause of death in patients with retroperitoneal liposarcoma (RLPS). We aimed to establish a postoperative nomogram exclusively focused on RLPS for predicting local recurrence-free survival (LRFS).

METHODS

A cohort of 124 patients after surgical resection with curative intent in the Peking University Cancer Hospital Sarcoma Center were included in the study. Demographic, clinicopathologic, and treatment variables were analyzed using the Cox regression model. Significant clinically relevant variables in multivariable analysis were incorporated into the RLPS-specific nomogram. The discriminative ability and predictive accuracy of the nomogram were assessed by calculating the concordance index and drawing a calibration plot.

RESULTS

At a median follow-up of 26.5 (interquartile range 10.9-39.4) months, 71 patients had recurrent disease. The 3-year and 5-year LRFS rates were 35.6% (95% confidence interval, 27.0-46.9%) and 28.2% (95% CI 15.8-38.6%), respectively. Multivariate analysis identified the French Federation of Cancer Centers Sarcoma Group (FNCLCC) grade and completeness of resection as independent predictors of LRFS. Variables included in our nomogram were: presentation status, multifocality, completeness of resection, histologic subtypes, and FNCLCC grade. The concordance index of our nomogram was 0.732 (95% CI 0.667-0.797) and the calibration plot was excellent.

CONCLUSIONS

Our novel nomogram for patients with resected RLPS could improve recurrence risk stratification to explore molecular analysis associated with recurrence.

Recurrent retroperitoneal sarcomas: Clinical outcomes of surgical treatment and prognostic factors

BACKGROUND AND PURPOSE

Locoregional recurrence after resection of primary retroperitoneal sarcoma (RPS) is a challenging therapeutic issue. The objective of this study was to identify clinicopathological factors predictive of overall survival (OS) and disease specific survival (DSS) after reoperation for recurrent RPS.

PATIENTS AND METHODS

We retrospectively collected data from the medical records of 800 patients who underwent resection for sarcoma at our Institution, from 1983 to 2015. Among these patients, 120 were treated for retroperitoneal sarcoma and 55 had a locoregional recurrence (LR). Four of them did not undergo surgery and thus were excluded from this study leaving 51 cases available for data analysis. Univariate and multivariate survival analyses were performed to identify prognostic factors.

RESULTS

Median overall survival was 33 months. The 1-year, 3-year and 5-year OS rates were 75.5%, 47.1% and 31.6% respectively. Multivariate Cox regression analysis suggested that extension of surgery (P = 0.026), surgical margin status (P = 0.015) and histological grade of recurrent tumor (P = 0.047) were independent prognostic factors for OS. Median DSS was 48 months. The 1-year, 3-year and 5-year DSS rates were 79.2%, 53.1% and 40.9%, respectively. At multivariate analysis, predictors of DSS were extension of surgery (P = 0.004), margin status (P = 0.011), histological grade of recurrent tumor (P = 0.008), and disease free interval (DFI) (P = 0.020). As regards histological subtype of recurrent RPS, at univariate analysis, well-differentiated liposarcoma (WDLS) was associated with better OS and DSS (P = 0.052 and P = 0.016 respectively) compared to dedifferentiated liposarcoma (DDLS).

CONCLUSIONS

According to our findings, surgery is more beneficial in patients with low-grade sarcoma, WDLS and long DFI. The achievement of clear resection margins, rather than performing a multivisceral resection, appears to be a key factor to improve OS and DSS.

Soft Tissue Tumors of the Abdomen and Retroperitoneum

Soft tissue tumors of the abdomen and retroperitoneum encompass a wide range of benign and malignant neoplasms. Retroperitoneal sarcomas, the most common, are composed of rare malignancies with numerous histiotypes. Surgery remains the cornerstone of treatment and the only curative option for retroperitoneal sarcomas. With histiotype-dependent local and distant recurrences, it is imperative these cases are discussed in a multidisciplinary tumor board setting at specialized sarcoma centers. This review discusses the current evidence for the management of abdominal and retroperitoneal soft tissue tumors, with particular focus on retroperitoneal sarcomas and desmoid tumors.

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

BACKGROUND AND OBJECTIVES

Resection of primary retroperitoneal sarcomas (RPS) has a high incidence of recurrence. This study aims to identify patterns of recurrence and its impact on overall survival.

METHODS

Adult patients with primary retroperitoneal soft tissue sarcomas who underwent resection in 2000-2016 at eight institutions of the US Sarcoma Collaborative were evaluated.

RESULTS

Four hundred and ninety-eight patients were analyzed, with 56.2% (280 of 498) having recurrences. There were 433 recurrences (1-8) in 280 patients with 126 (25.3%) being locoregional, 82 (16.5%) distant, and 72 (14.5%) both locoregional and distant. Multivariate analyses revealed the following: Patient age P = .0002), tumor grade (P = .02), local recurrence (P = .0003) and distant recurrence (P < .0001) were predictors of disease-specific survival. The 1-, 3-, and 5-year survival rate for patients who recurred vs not was 89.6% (standard error [SE] 1.9) vs 93.5% (1.8), 66.0% (3.2) vs 88.4% (2.6), and 51.8% (3.6) vs 83.9% (3.3), respectively, P < .0001. Median survival was 5.3 years for the recurrence vs 11.3+ years for the no recurrence group (P < .0001). Median survival from the time of recurrence was 2.5 years.

CONCLUSIONS

Recurrence after resection of RPS occurs in more than half of patients independently of resection status or perioperative chemotherapy and is equally distributed between locoregional and distant sites. Recurrence is primarily related to tumor biology and is associated with a significant decrease in overall survival.

Huge primary dedifferentiated pancreatic liposarcoma mimicking carcinosarcoma in a young female: A case report

BACKGROUND

Pancreatic liposarcoma is a rare tumor. According to a literature review, the patient described in this study is the seventh case of pancreatic liposarcoma reported in the English literature and the third case of dedifferentiated liposarcoma. Furthermore, this case had the largest primary tumor volume, and a primary pancreatic liposarcoma was diagnosed based on sufficient evidence.

CASE SUMMARY

We here report a rare case of a 28-year-old female with a huge dedifferentiated liposarcoma in the pancreatic tail. In June 2015, the patient underwent distal pancreatectomy with splenectomy. During the operation, a huge liposarcoma of approximately 28.0 cm × 19.0 cm × 8.0 cm was found, which had a yellow and white fish-like incisal surface. Based on both pathology and MDM2 gene amplification, the tumor was diagnosed as a dedifferentiated liposarcoma. The patient was treated with surgery but declined postoperative chemotherapy. She was well at the 26-mo follow-up, and no relapse was observed.

CONCLUSION

Pancreatic liposarcoma has a low incidence. Chemotherapy should be included in the treatment regimens. Complete resection is the only effective treatment.

Predictors of Disease-Free and Overall Survival in Retroperitoneal Sarcomas: A Modern 16-Year Multi-Institutional Study from the United States Sarcoma Collaboration (USSC)

Background

Retroperitoneal sarcomas (RPS) comprise approximately 15% of all soft-tissue sarcomas and frequently associated with significant morbidity and as little as 30% 5-year survival. Here, we provide a large, contemporary, and multi-institutional experience to determine which tumor, patient, and treatment characteristics are associated with long-term outcomes in RPS.

Methods

571 patients with primary RPS were identified from the United States Sarcoma Collaboration (USSC). RPS patients who underwent resection from January 2000 to April 2016 were included with patient, tumor, and treatment-specific variables investigated as independent predictors of survival. Survival analyses for disease-free and overall survival were conducted using Kaplan–Meier and Cox proportional hazards model methods.

Results

The study cohort was 55% female, with a median age of 58.9 years (IQR: 48.6–70.0). The most common tumor histiotypes were liposarcoma (34%) and leiomyosarcoma (28%). Median follow-up was 30.6 months (IQR: 11.2–60.4). Median disease-free survival was 35.3 months (95% CI: 27.6–43.0), with multivariate predictors of poorer disease-free survival including higher grade tumors, nodal-positive disease, and multivisceral resection. Median overall survival was 81.6 months (95% CI: 66.3–96.8). Multivariate predictors of shorter overall survival included higher grade tumors, nodal-positive and multifocal disease, systemic chemotherapy, and grossly positive margins (R2) following resection.

Conclusions

The strongest predictors of disease-free and overall survival are tumor-specific characteristics, while surgical factors are less impactful. Nonsurgical therapies are not associated with improved outcomes despite persistent interest and utilization. Complete macroscopic resection (R0/R1) remains a persistent potentially modifiable risk factor associated with improved overall survival in patients with retroperitoneal sarcomas.

Aggressive Surgical Approach for Treatment of Primary and Recurrent Retroperitoneal Soft Tissue Sarcoma

To analyze treatment and survival in a series of resected patients with primary or recurrent retroperitoneal sarcoma (RPS) treated and prospectively followed at a single institution. Between July 1994 and December 2015, 89 patients (36 M, 53 F; mean age 60 years, range 25-79) were evaluated. For the purpose of analysis, complete resection was defined as removal of gross tumor with histologically confirmed clear resection margins. Eighty-three out of the 89 patients (93%), 46 of whom affected by primary RPS, and 37 by recurrent RPS, underwent surgical exploration. Sixty-two had a grossly and microscopically complete resection. Fifty-three out of 83 patients (64%) underwent removal of contiguous intra-abdominal organs. Preoperative mortality was nil and significant preoperative complications occurred in six cases only (7%). High-grade tumor pointed out to be a significant variable for a worse survival in all 83 patients amenable to undergo surgical resection (57% 5 years survival for low grade vs 14% for high grade; P = 0.0004). Among completely resected patients, only histologic grade clearly affected disease-free survival (72% 5 years survival for low grade vs 50% for high grade; P = 0.04), while the role of preoperative blood transfusions (67% 5 years survival for non-transfused patients vs 29% for transfused patients; P = 0.05) has to be evaluated in connection to patient complexity. Histological grade and recurrence are the most valuable prognostic predictors; in this clinical subset, an aggressive surgical approach in both primary and recurrent RPS is associated with a best long-term survival and disease-free survival.

Importance of preoperative diagnosis for management of patients with suspected retroperitoneal sarcoma

Soft tissue sarcoma is an umbrella term which encompasses over 60 histological tumour types. Approximately 15% of soft tissue sarcomas arise in the retroperitoneum. This complex group of tumours poses unique management challenges due to their often large size, histological heterogeneity and complexity of anatomical relationships. This review discusses the management of retroperitoneal tumours including the need for preoperative diagnosis, the evidence for neoadjuvant radiotherapy, the role of multivisceral resection and the importance of a multidisciplinary team approach.

Management of Recurrent Retroperitoneal Sarcoma (RPS) in the Adult: A Consensus Approach from the Trans-Atlantic RPS Working Group

INTRODUCTION

Retroperitoneal soft tissue sarcomas (RPS) are rare tumors. Surgery is the mainstay of curative therapy, but local recurrence is common. No recommendations concerning the best management of recurring disease have been developed so far. Although every effort should be made to optimize the initial approach, recommendations to treat recurring RPS will be helpful to maximize disease control at recurrence.

METHODS

An RPS transatlantic working group was established in 2013. The goals of the group were to share institutional experiences, build large multi-institutional case series, and develop consensus documents on the approach to this difficult disease. The outcome of this document applies to recurrent RPS that is nonvisceral in origin. Included are sarcomas of major veins, undifferentiated pleomorphic sarcoma of psoas, ureteric leiomyosarcoma (LMS). Excluded are desmoids-type fibromatosis, angiomyolipoma, gastrointestinal stromal tumors, sarcomas arising from the gut or its mesentery, uterine LMS, prostatic sarcoma, paratesticular/spermatic cord sarcoma, Ewing sarcoma, alveolar/embryonal rhabdomyosarcoma, sarcoma arising from teratoma, carcinosarcoma, sarcomatoid carcinoma, clear cell sarcoma, radiation-induced sarcoma, paraganglioma, and malignant pheochromocytoma.

RESULTS

Recurrent RPS management was evaluated from diagnosis to follow-up. It is a rare and complex malignancy that is best managed by an experienced multidisciplinary team in a specialized referral center. The best chance of cure is at the time of primary presentation, but some patients may experience prolonged disease control also at recurrence, when the approach is optimized and follows the recommendations contained herein.

CONCLUSIONS

International collaboration is critical for adding to the present knowledge. A transatlantic prospective registry has been established.

Oncology outcomes in Retroperitoneal sarcomas: Prognostic factors in a Retrospective Cohort study

INTRODUCTION

Retroperitoneal sarcomas are a rare group of malignant soft tissue tumors with a generally poor prognosis. The aim of the study was to define the demographic characteristics and prognostic factors for patients with retroperitoneal sarcomas (RPS) in a Tertiary Referral Center at Mexico.

METHODS

A retrospective study of patients with RPS treated from January 2005 to December 2012 at the National Cancer Institute at Mexico. Patient, tumor and treatment variables were analyzed including use of adjuvant therapy and survival status. Survival and local recurrence curves were estimated using the Kaplan-Meier method.

RESULTS

Ninety-five patients with a mean age of 47 years with retroperitoneal sarcoma were included. Median follow-up was 25 months (range 1-108 months). The average tumor size was 23.7 cm. Histology, 58 (61.1%) were liposarcoma, 14 (14.7%), leiomyosarcomas and 23 (24.2%) were from other histologies. In 64 (67.4%) patients were high-grade malignancies. The median survival was 51 months for patients with complete resection, 25.1 months for those with incomplete resection, and 4.4 months for those with unresectable tumors. Complete resection (p = 0.0001), and liposarcoma (p = 0.03) were prognostic factors for overall survival.

CONCLUSION

In this study of patients with retroperitoneal, complete resection and liposarcoma histology are prognostic factors related to the disease-free and overall survival. Patients approached with curative intent should undergo aggressive attempts at complete surgical resection.

[Intra-abdominal and retroperitoneal sarcomas]

Sarcomas are a heterogeneous group of rare tumors that originate from mesenchymal tissue. Radical R0 resection is the only curative option, which is especially challenging in retroperitoneal or intra-abdominal sarcomas. This article describes the current data on optimal interdisciplinary and primarily surgical therapy of visceral sarcomas. Surgical resection of retroperitoneal sarcomas must be performed according to the principle of radical compartmental resection, i.e. with complete excision of the mass along with en bloc visceral resection of adjacent organs and tissues covering the tumor, which also contains any not obviously infiltrated neighboring organs. The main objective is R0 resection without opening the tumor capsule in the primary operation because the best long-term results can be achieved with this approach.

Long-term morbidity after multivisceral resection for retroperitoneal sarcoma

Background

More than 60 per cent of patients treated surgically for primary retroperitoneal sarcoma survive for at least 5 years. Extended surgical resection has been proposed for primary disease, but long-term morbidity data are lacking. A cross-sectional study was conducted to assess the long-term morbidity of patients undergoing surgery for retroperitoneal sarcoma.

Methods

Patients operated on between January 2002 and December 2011 were eligible for the study. Long-term morbidity was evaluated based on a semistructured clinical interview. Lower limb function was assessed by means of the Lower Extremity Functional Scale (LEFS), a self-report questionnaire with a total score ranging from 0 (low functioning) to 80 (high functioning). Pain was investigated by means of the Brief Pain Inventory – Short Form, with pain intensity scores reported on a scale from 0 (no pain) to 10 (worst pain).

Results

Some 243 patients underwent surgery, and 101 of 160 patients who were alive at the time of the investigation responded to the study invitation letter. Finally, 95 patients were enrolled in the study. Sensory impairment of the limbs was reported in 72 patients (76 per cent). The median LEFS score was 60 (i.q.r. 43–73). Mean scores for the pain intensity items varied from 1·23 to 2·68. In multivariable analysis, there was no difference in median levels of creatinine at survey between patients who did or did not undergo nephrectomy (difference between median values 13 (95 per cent c.i. −4 to 30) µmol/l; P = 0·170).

Conclusion

Severe chronic pain and lower limb motor impairment after multivisceral resection for retroperitoneal sarcomas are rare. Long-term renal function is not significantly impaired when nephrectomy is performed.

Combined Modality Management of Retroperitoneal Sarcomas: A Single-Institution Series of 121 Patients

PURPOSE

The purpose of this study was to investigate local control, survival outcomes, and complication rates of patients treated with aggressive surgery and radiation therapy (RT) for retroperitoneal sarcomas (RPS).

METHODS AND MATERIALS

We reviewed the medical records of 121 consecutive patients treated for RPS with surgery and RT between 1965 and 2012. The most common histology was liposarcoma (n = 42; 35%). The median follow-up was 100 months (range: 20-467 months). Eighty-six patients (71%) were treated for initial presentation of RPS, and 35 patients (29%) presented with and were treated for RPS recurrence. RT was preoperative in 88 patients (73%; median dose: 50.4 Gy) and postoperative in 33 patients (27%; median dose: 55 Gy).

RESULTS

Five-year local control and overall survival rates were 56% and 57%, respectively. Two factors were associated with higher risk of any intra-abdominal recurrence at 5 years: positive or uncertain margins (58% vs 30% for negative margins, P < .001; hazard ratio [HR]: 2.7; 95% confidence interval [CI]: 1.6-4.8) and disease recurrence after previous resection (76% vs 31% for de novo RPS, P < .001; HR: 4.4; 95% CI: 2.5-7.5). The 10-year complication rate was 5%, and RT-related complications were associated with postoperative RT (P < .001) and RT dose of ≥ 60 Gy (P < .001).

CONCLUSIONS

Intra-abdominal RPS recurrence continues to be a significant challenge despite the use of aggressive surgery and radiation therapy. Given the complications associated with postoperative radiation therapy, we recommend that preoperative radiation therapy is the preferred strategy when combined modality therapy is recommended.

Personalizing surgical margins in retroperitoneal sarcomas

Retroperitoneal sarcomas are a group of diseases that behave differently from one another. Well-differentiated liposarcomas have an indolent biology but show a tendency to recur locally even years after primary resection. Dedifferentiated liposarcomas are characterized by a very high local recurrence risk, while the metastatic risk mainly depends on the histological characteristics of the dedifferentiated component. In leiomyosarcomas, hematogenous spread informs prognosis while local recurrences are far less common. Surgery is the cornerstone of treatment of all retroperitoneal sarcoma subtypes and its quality is the only treatment-related factor able to improve the oncological outcome. A frontline extended surgical approach is all the more critical in subtypes in which local control directly impacts prognosis.

Surgical management of retroperitoneal and pelvic sarcomas

Management of retroperitoneal sarcomas presents technical and oncological challenges. Imaging is crucial for diagnosis and to define local tumor extent. Complete gross resection at initial presentation is the best chance for cure, but there is controversy as to how this can be best achieved. There is a long-term risk of local recurrence, which is best treated with repeat resection if feasible. The roles of radiation and chemotherapy remain undefined.