Predictors of outcomes in patients with primary retroperitoneal dedifferentiated liposarcoma undergoing surgery

Histology-Tailored Approach to Soft Tissue Sarcoma

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

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.

Dedifferentiated liposarcoma of the extremities: a Korean multi-center study of 107 cases

BACKGROUND

Dedifferentiated liposarcoma of the extremities (DDL-E) is rare in comparison to that of the retroperitoneum. Its clinical features and surgical principle for resection margins at the dedifferentiated and the well-differentiated components are yet to be elucidated.

METHODS

This retrospective multi-center study examined patients diagnosed with DDL-E from August 2004 to May 2023 at 5 sarcoma centers. Clinical features, oncologic outcomes, and prognostic factors were analyzed.

RESULTS

A total of 107 patients were reviewed. The 5-year local recurrence free survival (LRFS), metastasis-free survival (MFS) and disease specific survival (DSS) were 84.7%, 78.6%, and 87.8%, respectively. Other primary malignancies and extrapulmonary metastasis were observed in 27 and 4 patients, respectively. The independent risk factor for local recurrence was R1/2 margin at the dedifferentiated component of the tumor. Metastasis was associated with tumor size in univariate analysis. The independent risk factor for DSS was tumor grade. Previous unplanned excision, de novo presentation, tumor depth, absence of the well-differentiated component, infiltrative border, R1/2 margin at the well-differentiated component were not associated with oncologic outcomes.

CONCLUSIONS

This is the largest study examining DDL-E to-date. Localized DDL-E has low potential for metastasis and carries an excellent prognosis. Other primary malignancy and extrapulmonary metastasis are more frequent in DDL-E, thus close monitoring of other sites during follow-up is recommended. While wide resection margin is the standard surgical approach for DDL-E, further investigation into moderated wide resection margin at the well-differentiated component is warranted.

A preliminary study of primary retroperitoneal sarcoma at a tertiary University Hospital in Bangkok, Thailand: a retrospective observational study

Background

Retroperitoneal sarcoma (RPS) is rare and difficult to treat with a high recurrent rate. Very little data regarding primary RPS exists in Thailand.

Objectives

To study the outcome of treatment of primary RPS at a tertiary University Hospital in Bangkok, Thailand.

Methods

All patients who had RPS undergoing the first surgical resection at King Chulalongkorn Memorial Hospital from June 2003 to December 2019 were retrospectively enrolled in the study. Perioperative management, results of treatment, postoperative complications, and outcome were analyzed.

Results

Thirty-eight patients entered the study. Large abdominal mass was the most common presentation (90%). Liposarcoma was the most common histology (58%). Twenty patients (53%) had preoperative core needle biopsy and 21 (55%) underwent preoperative radiotherapy (RT). The tumor size ranged from 3 cm to 48 cm (median 22 cm). Five patients (13%) had total mass removal only while 33 (87%) had complete gross resection with ≥1 visceral organ resection. Surgical margins classified as R0, R1, and R2 were 61%, 34%, and 5%, respectively. Five patients (16%) had postoperative complications. There was no 30-day postoperative mortality. The local recurrence rate was 34%. Survival analysis revealed a 5-year overall survival rate of 37% and 5-year disease-free survival rate of 29%. The 5-year and 10-year recurrent rates were 71% and 95%, respectively. Multivariate analysis showed that preoperative radiation was the only factor reducing recurrence (19% vs. 53%, OR: 0.21, P = 0.011).

Conclusion

The preliminary study of outcome of the treatment of primary RPS at our institution showed a fair prognosis of this rare malignancy despite our aggressive surgical approaches. Preoperative radiation may help reduce recurrence in selected primary RPS patients.

Esophageal dedifferentiated liposarcoma resected by the cervical approach: a case report

BACKGROUND

While liposarcomas tend to mainly occur in the soft tissues of the extremities and retroperitoneum, esophageal liposarcoma is rare. Herein, we report a case of a patient who underwent complete resection of an esophageal dedifferentiated liposarcoma via the cervical approach, leading to the preservation of the esophagus.

CASE PRESENTATION

A 69-year-old man underwent an upper gastrointestinal endoscopy, as a result of which a submucosal-like tumor was observed. Upper gastrointestinal imaging showed a 12-cm tumor with a stalk arising from the esophageal entrance, extending to the middle intrathoracic esophagus, with a normal surface mucosa. Endoscopic ultrasound-fine needle aspiration biopsy showed that the nuclei of tumors cells were positive for murine double minute (MDM) and weakly positive for cyclin-dependent kinase 4 (CDK4). We diagnosed the tumor as the esophageal dedifferentiated liposarcoma, and planed tumor resection via the cervical approach. The tumor was successfully resected and the postoperative course was uneventful.

CONCLUSION

This case report highlights the use of tumor resection via the cervical approach as a good option for esophageal liposarcoma.

Transmediastinal primary pulmonary liposarcoma: Case report and review of management strategies

Soft tissue sarcomas account for less than 1% of new cancer diagnoses, approximately one in five of which are liposarcomas. These tumors typically arise in the deep tissues of the proximal extremity or retroperitoneum, with just under 3% presenting as primary intrathoracic neoplasms. We present an exceedingly rare and particularly unique presentation of primary lung liposarcoma which traversed the mediastinum into the contralateral hemithorax. This report highlights the primary characteristics of the disease and underscores the importance of a multidisciplinary approach to its successful treatment.

Dedifferentiation in bone and soft tissue sarcomas: How do we define it? What is prognostically relevant?

Dedifferentiation traditionally is defined by descriptive criteria as a tumor showing an abrupt change in histology from a conventional, classic, low-grade appearing neoplasm to a tumor that is more cellular, pleomorphic and "high grade", with grading typically being performed by subjective criteria. The dedifferentiated areas range from areas with recognizable histologic differentiation which differs from the primary tumor (such as an osteosarcoma arising from a low-grade chondrosarcoma) to areas containing sarcomas without specific histologic differentiation (such as pleomorphic or spindle cell sarcoma). Many, but not all, dedifferentiated tumors are aggressive and associated with significantly shorter survival than their conventional counterparts, even grade 3 conventional tumors. As a result, dedifferentiated tumors are generally considered to be clinically aggressive and as a result, more aggressive surgery or the addition of (neo)adjuvant chemotherapy is often considered. However, long-term (greater than 20 year) survivors are reported in the most common dedifferentiated bone and soft tissue sarcomas. Moreover, use of mitotic criterion for defining dedifferentiation in dedifferentiated liposarcoma as well as grading (by the French system) have been found to be associated with survival. This paper reviews the literature on dedifferentiated chondrosarcoma, dedifferentiated liposarcoma, dedifferentiated chordoma and dedifferentiated parosteal osteosarcoma. As a result of that review, recommendations are advocated to identify evidence-based, objective diagnostic and grading criteria for dedifferentiation that are appropriate for each tumor type. Adding such criteria will improve consistency in diagnosis worldwide, allow easier comparison of clinical research performed on dedifferentiated tumors and help communicate (to patients and clinicians) the tumors with highest risk of clinically aggressive behavior, to allow appropriate and personalized treatment planning.

Analysis of recurrence and metastasis patterns and prognosis after complete resection of retroperitoneal liposarcoma

Objective

To analyze the recurrence and metastasis patterns and prognosis after complete resection of retroperitoneal liposarcoma.

Methods

The clinical postoperative follow-up data and results of patients who underwent complete resection of retroperitoneal liposarcoma from September 10, 2014, to September 8, 2021, at Hebei Medical University hospital were collected retrospectively.

Results

A total of 60 patients with complete resection of retroperitoneal liposarcoma, including 33 cases of retroperitoneal liposarcoma recurrence, 2 cases of liver metastasis, and 1 case of lung metastasis, were included. The results showed that 100% of the recurrent sites were located in the primary region of the tumor, with most recurrences located near the kidney, paracolic sulci, and iliac vessels. Three patients had distant metastasis without obvious recurrence on imaging examination. The pathological type of retroperitoneal liposarcoma, Ki67 expression, and presence of serum albumin were risk factors for recurrence and metastasis after complete resection of retroperitoneal liposarcoma. The malignancy and Ki67 expression were independent risk factors for recurrence and metastasis as well as for overall survival of patients undergoing complete resection of retroperitoneal liposarcoma.

Conclusion

Complete resection remains the most effective method to treat retroperitoneal liposarcoma. Patients with pathological types of retroperitoneal liposarcoma showing dedifferentiation, pleomorphism, mixed type, and high Ki67 expression should be closely monitored and observed after complete resection, especially for imaging changes in the primary tumor area.

Predictors and outcomes of recurrent retroperitoneal liposarcoma: new insights into its recurrence patterns

BACKGROUND

The clinical profiles of recurrent retroperitoneal liposarcoma (RLS) need to be explored. The recurrence patterns of RLS are controversial and ambiguous.

METHODS

A total of 138 patients with recurrent RLS were finally recruited in the study. The analysis of overall survival (OS) and recurrence-free survival (RFS) was performed by Kaplan‒Meier analysis. To identify independent prognostic factors, all significant variables on univariate Cox regression analysis (P ≤ 0.05) were subjected to multivariate Cox regression analysis. The corresponding nomogram model was further built to predict the survival status of patients.

RESULTS

Among patients, the 1-, 3-, and 5-year OS rates were 70.7%, 35.9% and 30.9%, respectively. The 1-, 3- and 5-year RFS rates of the 55 patients who underwent R0 resection were 76.1%, 50.8% and 34.4%, respectively. The multivariate analysis revealed that resection method, tumor size, status of pathological differentiation, pathological subtypes and recurrence pattern were independent risk factors for OS or RFS. Patients with distant recurrence (DR) pattern usually had multifocal tumors (90.5% vs. 74.7%, P < 0.05); they were prone to experience changes of pathological differentiation (69.9% vs. 33.3%, P < 0.05) and had a better prognosis than those with local recurrence (LR) pattern. R0 resection and combined organ resection favored the survival of patients with DR pattern in some cases.

CONCLUSIONS

Patients with DR pattern had better prognosis, and they may benefit more from aggressive combined resection than those with LR pattern. Classifying the recurrence patterns of RLS provides guidance for individualized clinical management of recurrent RLS.

Neoadjuvant Chemotherapy in Retroperitoneal Sarcoma: A National Cohort Study

INTRODUCTION

Management of retroperitoneal sarcoma (RPS) remains controversial, with the mainstay of treatment being surgery. While neoadjuvant radiation demonstrated no improvement in recurrence-free survival in a prospective randomized trial (STRASS), the role of neoadjuvant chemotherapy (NCT) remains unknown and is the subject of ongoing study (STRASS2).

METHODS

Patients who underwent surgical resection of high-grade RP leiomyosarcoma (LMS) or dedifferentiated liposarcoma (DDLS) were identified from the National Cancer Database (2006-2019). Predictors of NCT were analyzed using univariate and multivariate logistic regression analyses. Differences in 5-year survival were examined using the Kaplan-Meier (KM) method and by Cox proportional hazard modeling.

RESULTS

A total of 2656 patients met inclusion criteria. Fifty-seven percent of patients had DDLS and 43.5% had LMS. Six percent of patients underwent NCT. Patients who received NCT were younger (median age 60 vs 64 years, p < 0.001) and more likely to have LMS (OR 1.4, p = 0.04). In comparing NCT with no-NCT patients, there was no difference in 5-year overall survival (OS) on KM analysis (57.3% vs 52.8%, p = 0.38), nor was any difference seen after propensity matching (54.9% vs 49.1%, p = 0.48, N = 144 per group). When stratified by histology, there was no difference in OS based on receipt of NCT (LMS: 59.8% for NCT group, 56.6% for no-NCT, p = 0.34; DDLS: 54.2% for NCT group, 50.1% for no-NCT, p = 0.99).

CONCLUSION

In patients undergoing surgical resection of RP LMS or DDLS, NCT does not appear to confer an OS advantage. Prospective randomized data from STRASS2 will confirm or refute these retrospective data.

Multivisceral resection for retroperitoneal liposarcoma-is it worth it? A 20-year single-center experience

PURPOSE

Soft tissue sarcomas are rare malignant tumors. Liposarcoma constitutes the most frequent histological subtype of retroperitoneal sarcoma. The prognosis of soft tissue sarcomas depends on clinical and histologic characteristics.

OBJECTIVE

Evaluate variables that may be related to the overall and local recurrence-free survival in patients with retroperitoneal liposarcoma and discuss the need for visceral resection en-bloc for tumors.

METHODS

A retrospective analysis was conducted of the medical records of 60 patients seen between 1997 and 2017 who underwent surgical resection of retroperitoneal liposarcoma.

RESULTS

The overall survival rate at 5 years of follow-up was 75.22% (95% confidence interval [CI] 0.58-0.86). The probability of a local recurrence-free survival at 5 years of follow-up was 26.04% (95% CI 0.11-0.44). The multivariate analysis showed that dedifferentiated or pleomorphic tumors and R2/fragmented resection were associated with a shorter time to recurrence. No other characteristics markedly influenced the overall survival (P > 0.05).

CONCLUSION

Patients with dedifferentiated or pleomorphic tumors and incomplete resection were associated with higher local recurrence rates than others. This study reinforces the need for complete and en-bloc resection with organs when there is clear involvement or technical surgical difficulty to maintain the tumor integrity.

Predictors and outcomes of recurrent retroperitoneal liposarcoma with multiple tumors

Background

Retroperitoneal liposarcoma (RLS) is a rare but severe disease. Repeated postoperative recurrence with multiple tumors is a therapeutic dilemma. The clinical outcomes and survival predictors of recurrent RLS with multiple tumors remain to be explored.

Methods

Patients with recurrent RLS were retrospectively analyzed. Univariate and multivariate analysis was performed to find independent prognostic factors that were correlated with Overall survival (OS) or progression-free survival (PFS). Factors significant in univariate analysis were further included into multivariate Cox proportional hazards regression model. The nomogram model was built to predict the survival status of patients. Variables that were significant in multivariable analysis were added to the internally validated nomogram models. The analysis of OS and PFS was performed by Kaplan-Meier analysis and log-rank test.

Results

A total of 113 recurrent RLS patients with multiple tumors were enrolled in the study. The 1-, 3-, and 5-years OS (PFS) rates were 70.7% (76.1%), 35.9% (76.1%), and 30.9% (76.1%), respectively. Univariate and multivariate analyses showed that number of surgeries, resection methods, tumor size, status of pathological differentiation, pathological subtypes, and recurrence patterns were important prognostic factors for OS or PFS (each p < 0.05). Nomogram models were established to efficiently predict the prognostic status of patients. Patients with the local recurrence (LR) pattern had a poor prognosis and would derive no survival benefit from combined organ resection and R0/R1 resection (each p < 0.05).

Conclusion

RLS patients recurrence with multiple tumors had a poor prognosis. Those patients should be followed up more frequently after surgery. The strategies of aggressive resection may not improve the survival of patients with LR pattern in the retroperitoneum. Prognostic factors in the efficient nomogram models should be considered in the individualized clinical management of recurrent RLS with multiple tumors.

Survival of a patient with five recurrences of retroperitoneal liposarcoma over a period of 13 years: A case report and review

Retroperitoneal liposarcoma (RPLS) is a rare tumor that occurs in the retroperitoneal region and accounts for ~0.2% of all malignant tumor incidence. The present study describes the treatment of a surviving patient with RPLS that recurred five times in 13 years. This case has a long survival time and numerous relapses, which is a rare occurrence. The 40-year-old female patient was admitted to Shaoxing Second Hospital (Shaoxing, China) with an abdominal mass. Abdominal computed tomography (CT) scan revealed multiple liposarcoma recurrences in the abdominal, pelvic and retroperitoneal areas. As the diagnosis of RPLS was the fifth recurrence, cytoreductive surgery was performed and post-operative pathology suggested mixed liposarcoma. The patient underwent six cycles of doxorubicin and ifosfamide regimen chemotherapy and targeted therapy with anlotinib following surgery; no evidence of disease progression was found on abdominal CT scan during follow-up. The present study also reviewed the literature in terms of the clinical diagnosis, treatment, pathological characteristics and similar cases of liposarcoma with the aim of improving diagnosis and treatment.

Malignant adipocytic tumours: A 20‑year single‑centre retrospective study

Adipocytic tumours are the most common soft tissue neoplasms. Among them, liposarcoma is the most frequent malignant neoplasm. However, to the best of our knowledge, no previously published study has assessed the evolution and oncological prognosis of the different subtypes of liposarcoma at the retroperitoneal level compared with at other locations. The present study is a retrospective observational study in which all patients were operated on between October 2000 and January 2020 with a histological diagnosis of liposarcoma. Variables, such as age, sex, location, histological type, recurrence, type of treatment and mortality, among others, were analysed. The patients were divided into two groups: Group A (retroperitoneal location) and group B (non-retroperitoneal location). A total of 52 patients with a diagnosis of liposarcoma (17 women and 35 men) and a mean age of 57.2±15.9 years were assessed. A total of 16 patients were classified into group A and 36 into group B. The OR of recurrence was 1.5 (P=0.02) for R1 vs. R0 resection in group A. The OR of recurrence in group B for R1 vs. R0 resection was 1.8 (P=0.77), whereas for R2 vs. R0 resection, the OR was 69 (P=0.011). In conclusion, 52 cases of malignant adipocytic tumours collected during 2000-2020 were analysed with the new World Health Organization classification (updated 2020). Although its recurrence potential and capacity for distant metastasis depended on each histological type, surgical treatment with unaffected margins was the main prognostic factor for survival. The present study identified differences in relation to the survival of each histological subtype and its location, finding greater survival in dedifferentiated liposarcoma, myxoid liposarcoma and pleomorphic liposarcoma located at the extraperitoneal level than in the retroperitoneal location. Resectability was not influenced by liposarcoma location.

The Role of Surgery in Oligometastatic Retroperitoneal Sarcoma

Retroperitoneal sarcomas are extremely rare, comprising <15% of primary sarcomas. Distant metastasis occurs in about 20% of cases, with pulmonary and hepatic metastasis as the most common sites of hematogenous spread. Although surgical resection is well established as the main treatment of localized primary disease, there are limited guidelines for the surgical treatment of intra-abdominal and distant metastases. There are inadequate systemic treatment options for patients with metastatic sarcoma, thereby necessitating the consideration of surgical options in carefully selected patients. Key points to consider include tumor biology, patient fitness and co-morbidities, overall prognosis, and goals of care. Multidisciplinary sarcoma tumor board discussion for each case is an essential practice in order to deliver the best care to these patients. The purpose of this review is to summarize the published literature on the past and present role of surgery in the treatment of oligometastatic retroperitoneal sarcoma in order to inform the management of this difficult disease.

Clinical Impact of External Beam Radiotherapy for Surgically Resected Primary Retroperitoneal Liposarcoma

INTRODUCTION

EORTC-62092 (STRASS) was a phase 3, randomized study that compared surgery alone versus surgery plus neoadjuvant radiotherapy (RT) for retroperitoneal sarcomas. RT was not associated with improved abdominal recurrence-free survival, the primary outcome measure, although on subanalysis, there may have been benefit for well-differentiated (WD) liposarcoma. This study investigated the real-world use and outcomes of RT (neoadjuvant and adjuvant) for the management of retroperitoneal liposarcoma.

METHODS

We queried the National Cancer Database (NCDB) (2004-2017) for patients with nonmetastatic, primary retroperitoneal liposarcoma treated with resection with or without RT (n = 3911). Patients were stratified by treatment type and histology [WD (n = 2252), dedifferentiated (DD) (n = 1659)]. Propensity score (PS) matching was used before comparison of treatment groups. Overall survival (OS) was the primary outcome measure.

RESULTS

Median follow-up time was 4.1 years, and median OS was 10.7 years. There was no association between RT and OS for either WDLPS or DDLPS cohorts. We performed a subgroup analysis of neoadjuvant RT only, similar to STRASS. For WDLPS after PS matching (n = 208), neoadjuvant RT was not associated with OS (hazard ratio [HR] 1.01, p = 0.0523) but was associated with longer postoperative hospital stay (p = 0.012). For DDLPS after PS matching (n = 290), neoadjuvant RT was not associated with OS (HR 1.02, p = 0.889). For both WD-LPS and DD-LPS, utilization of neoadjuvant RT was associated with treatment at high-volume (≥ 10 cases/year) and academic/network facilities.

CONCLUSIONS

For primary retroperitoneal liposarcoma treated with surgical resection, radiotherapy was not associated with an overall survival benefit in this propensity-matched, adjusted analysis of the NCDB.

Targeting the MDM2-p53 pathway in dedifferentiated liposarcoma

Dedifferentiated liposarcoma (DDLPS) is an aggressive adipogenic cancer with poor prognosis. DDLPS tumors are only modestly sensitive to chemotherapy and radiation, and there is a need for more effective therapies. Genetically, DDLPS is characterized by a low tumor mutational burden and frequent chromosomal structural abnormalities including amplification of the 12q13-15 chromosomal region and the MDM2 gene, which are defining features of DDLPS. The MDM2 protein is an E3 ubiquitin ligase that targets the tumor suppressor, p53, for proteasomal degradation. MDM2 amplification or overexpression in human malignancies is associated with cell-cycle progression and worse prognosis. The MDM2-p53 interaction has thus garnered interest as a therapeutic target for DDLPS and other malignancies. MDM2 binds p53 via a hydrophobic protein interaction that is easily accessible with synthetic analogues. Multiple agents have been developed, including Nutlins such as RG7112 and small molecular inhibitors including SAR405838 and HDM201. Preclinical in vitro and animal models have shown promising results with MDM2 inhibition, resulting in robust p53 reactivation and cancer cell death. However, multiple early-phase clinical trials have failed to show a benefit with MDM2 pathway inhibition for DDLPS. Mechanisms of resistance are being elucidated, and novel inhibitors and combination therapies are currently under investigation. This review provides an overview of these strategies for targeting MDM2 in DDLPS.

Evaluation of Efficacy of Adjuvant Radiotherapy in Well-Differentiated Liposarcoma Patients with Positive Surgical Margins: A Population-based Study

Background

The use of adjuvant radiotherapy (RT) for well-differentiated liposarcoma (WD-LPS) patients with positive surgical margins is unclear. We aim to compare the overall survival (OS) and cancer-specific survival (CSS) of well-differentiated liposarcoma patients with positive surgical margins in an RT group and non-RT group.

Methods

WD-LPS patients with positive margins from 2000 to 2018 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database and divided into two groups: RT group and non-RT group. Kaplan–Meier survival analysis with the log-rank test was performed to evaluate the difference of overall survival (OS) and cancer-specific survival (CSS) between groups. Univariate and multivariate Cox proportional hazard analyses were performed to identify important prognostic factors of OS and CSS. Analyses were adjusted using propensity-score matching.

Results

We identified 2549 patients: 377 (14.79%) with RT and 2172 (85.21%) without RT. The median age was 61 years, and the median follow-up time was 68 months. The log-rank test revealed that there was no significant difference of CSS between RT and non-RT groups (P = 0.81). The 5-year and 10-year CSS were comparable (P = 0.418 and P = 0.987). Additionally, the use of RT was neither an independent prognostic factor for OS nor CSS. Age, sex, tumor site, the use of chemotherapy were independent prognostic factors for OS after propensity score matching, while race and the tumor site were independent prognostic factors for CSS.

Conclusion

Adjuvant RT had no significant improvement on OS and CSS of WD-LPS patients with positive surgical margins.

Surgery of intraabdominal giant dedifferentiated liposarcoma of ascending colon mesentery: A rare case report

Introduction

Liposarcoma, a lipogenic tumor of large deep-seated connective tissue space, presents the most common type of soft tissue sarcoma arising in the retroperitoneum. Liposarcoma that arises from colonic mesentery is especially a very rare disease. The present case describes a surgery of giant dedifferentiated liposarcoma at ascending colon mesentery.

Presentation of case

A 47-year-old South Korean man was admitted and presented with palpable abdominal mass. Abdominal pelvic computed tomography scan revealed a huge mass at his right sided abdomen (about 25 × 19 cm sized mass at right abdomen with encapsulation). After the surgery, the entire mass was completely excised en bloc with the ascending colon. The specimen consisted of multinodular, pinkish tanned, focally myxoid tissue, which measured up to 25.5 × 19 × 12.5 cm. Final pathological analysis reported dedifferentiated liposarcoma (high grade sarcoma) with MDM2 and CDK2 (+) in immunohistochemistry.

Conclusion

The present case report concerns a 47-year-old male with giant dedifferentiated liposarcoma arising from colonic mesentery and achieved en-bloc resection of liposarcoma with right hemicolectomy.

•

Dedifferentiated liposarcoma arising from colonic mesentery is a rare form of the soft tissue sarcoma.

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In giant dedifferentiated liposarcoma, grossly complete resection is known as the better prognostic factor.

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liposarcoma excision with right hemicolectomy was inevitable for this case to achieve the complete resection due to colon wall invasion.

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.

Retroperitoneal and Mesenteric Liposarcomas

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

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.

Real-world use of palbociclib monotherapy in retroperitoneal liposarcomas at a large volume sarcoma center

Palbociclib has been evaluated in early phase trials for well-differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS) patients, with reported median progression-free survival (PFS) of 18 weeks. Here, we report on real-world use and surgical outcomes associated with palbociclib treatment. We retrospectively reviewed 61 consecutive patients with retroperitoneal WDLPS (n = 14) or DDLPS (n = 47) treated with palbociclib monotherapy between 1 March 2016 and 28 February 2021 at The University of Texas MD Anderson Cancer Center. At palbociclib initiation, median age was 64 (interquartile range [IQR] 56-72). In WDLPS and DDLPS cohorts, the median number of prior systemic treatments was 0 (IQR 0-0) and 2 (IQR 0-4), respectively. Median number of prior surgeries was 2 (WDLPS IQR 1-2.75) and 2 (DDLPS IQR 1-3). Median PFS was 9.2 (WDLPS IQR 3.9-21.9) and 2.6 months (DDLPS IQR 2.0-6.1), with median time on treatment of 7.4 months (WDLPS IQR 3.5-14.2) and 2.7 months (DDLPS IQR 2.0-5.7). Twelve patients ultimately underwent surgical resection. Resections were macroscopically complete (R0/R1) in half (n = 6/12), among whom only one patient experienced relapse after resection (median follow-up 7.5 months). All patients who underwent macroscopically incomplete resections progressed after surgery with median time to progression of 3.3 months (IQR 2.3-4.4). Surgery after palbociclib treatment was not associated with improved overall survival. Efficacy of palbociclib monotherapy for patients with advanced WDLPS and DDLPS is disappointing. While palbociclib may have been used to delay surgery, there was no clear benefit from treatment and few patients achieved prolonged tumor control.

Retroperitoneal Liposarcoma: An Unusual Presentation of a Rare Cancer

Retroperitoneal liposarcomas (RLPS) are rare tumors that have variable clinical behavior and complex treatment strategies based on presentation, histopathology, and genomics. Early identification is critical, and complete surgical resection remains the primary treatment, although chemotherapy and radiation are used on individual bases. Presenting symptoms are often nonspecific; therefore, a high degree of suspicion is essential for early diagnosis. In this report, the management of a 37-year-old otherwise healthy male with a large RLPS causing right groin/testicular pain is presented. After three evaluations in the emergency department, the patient was diagnosed and received two cycles of doxorubicin/ifosfamide/mesna (AIM) neoadjuvant chemotherapy. His physical exam on presentation for second opinion demonstrated a large palpable abdominal mass and fullness around the right spermatic cord. There was no appreciable change in tumor size or distant metastases on repeat scanning. Given some obstructive symptoms, a multidisciplinary team advised neoadjuvant radiation followed by radical resection of RLPS. Final pathology demonstrated a 31-cm grade II well-differentiated (WD) liposarcoma with low-grade dedifferentiation. Scattered foci of microscopic positive WD margins were noted, and the remainder of margins were negative. Genomic evaluation showed amplification of CDK4, MDM2, and FRS2. A concise literature review of common presentations, histopathology, genomics, and treatment information is discussed herein. Thorough physical exams, attention to subtle findings, appropriate medical imaging studies, and a high index of suspicion when evaluating vague symptomatology can lead to earlier diagnosis and treatment of RLPS, and ultimately better patient outcomes.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Soft Tissue Tumors

The fifth (5th) edition of the World Health Organization (WHO) Classification of Head and Neck Tumors introduces a new chapter dedicated to soft tissue neoplasms commonly affecting the head and neck. While the diversity, rarity, and wide anatomic range of soft tissue tumors precludes a discussion of all entities that may be found in the head and neck, the addition of this new chapter to the head and neck "blue book" aims to provide a more comprehensive and uniform reference text, including updated diagnostic criteria, of mesenchymal tumor types frequently (or exclusively) arising at head and neck sites. Since publication of the previous edition in 2017, there have been numerous advances in our understanding of the pathogenesis of many soft tissue tumors which have facilitated refinements in tumor classification, identification of novel entities, development of diagnostic markers, and improved prognostication. This review will provide a focused discussion of the soft tissue tumors included in the 5th edition WHO Head and Neck classification, with an emphasis on updates.

A successful trimodality therapy for difficult-to-diagnose primary mediastinal dedifferentiated liposarcoma, which originated from the perihilar fat and invaded the right lungs

A 40-year-old man with high fever, hemoptysis, and fatigue showed a 10-cm mass in the middle and lower lobes of the right lung on computed tomography. Histological examination of transbronchial biopsy specimens showed sheets of small round tumor cells and mild staining for CD99. Primary Ewing sarcoma was suspected, and a trimodality therapy consisting of chemotherapy, intensity-modulated radiation therapy, and right pneumonectomy with surrounding tissue resection was performed. In surgical specimens, negative outcome of NKX2.2 in immunostaining and EWSR1 rearrangement in fluorescence in situ hybridization did not support the diagnosis of Ewing sarcoma. Positive immunostaining for MDM2 and CDK4 led to a diagnosis of dedifferentiated liposarcoma, which probably originated from an adipose tissue of the right perihilar mediastinum, and then invaded the lungs. The postoperative course was uneventful, without recurrence for more than 16 months.

Retroperitoneal Dedifferentiated Liposarcoma

OBJECTIVES

We aimed to test the hypothesis that in retroperitoneal dedifferentiated liposarcoma (DDLS) the presence of the dedifferentiated (DD) component at the resection margin is associated with adverse outcome.

METHODS

We retrospectively searched the archive for primary resections of retroperitoneal DDLS performed at our institution between 1990 and 2017. Slides were rereviewed for diagnosis, Fédération Nationale des Centres de Lutte Contre le Cancer grade, myogenic differentiation, and the presence of the well-differentiated (WD) or DD component at the resection margin. The medical records were reviewed for patient age, sex, tumor size, tumor focality, adjuvant/neoadjuvant therapy, local recurrence, distant metastases, local recurrence-free survival (LRFS), overall survival (OS), and follow-up duration.

RESULTS

The presence of the DD component at the resection margin was associated with worse LRFS compared with cases without the DD component at the margin (P = .002). However, OS was not significantly affected (P = .11).

CONCLUSIONS

LRFS is significantly shorter in cases with the DD component at the margin compared with cases without DD tumor at the margin, while there is no association with OS. We recommend reporting the presence or absence of DD tumor at the margin in retroperitoneal DDLS, as it adds meaningful prognostic information.

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.

Update on genomic and molecular landscapes of well-differentiated liposarcoma and dedifferentiated liposarcoma

Well-differentiated liposarcoma (WDLPS) is the most frequent subtype of liposarcoma and may transform into dedifferentiated liposarcoma (DDLPS) which is a more aggressive subtype. Retroperitoneal lesions of WDLPS/DDLPS tend to recur repeatedly due to incomplete resections, and adjuvant chemotherapy and radiotherapy have little effect on patient survival. Consequently, identifying therapeutic targets and developing targeted drugs is critical for improving the outcome of WDLPS/DDLPS patients. In this review, we summarised the mutational landscape of WDLPS/DDLPS from recent studies focusing on potential oncogenic drivers and the development of molecular targeted drugs for DDLPS. Due to the limited number of studies on the molecular networks driving WDLPS to DDLPS development, we looked at other dedifferentiation-related tumours to identify potential parallel mechanisms that could be involved in the dedifferentiation process generating DDLPS.

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 2020 WHO Classification: What's New in Soft Tissue Tumor Pathology?

The fifth edition of the World Health Organization Classification of Tumors of Soft Tissue and Bone was published in early 2020. The revisions reflect a consensus among an international expert editorial board composed of soft tissue and bone pathologists, geneticists, a medical oncologist, surgeon, and radiologist. The changes in the soft tissue tumor chapter notably include diverse, recently described tumor types (eg, atypical spindle cell/pleomorphic lipomatous tumor, angiofibroma of soft tissue, and CIC-rearranged sarcoma), new clinically significant prognostic information for a variety of existing entities (eg, dedifferentiated liposarcoma and solitary fibrous tumor), and a plethora of novel genetic alterations, some of practical diagnostic relevance (eg, NAB2-STAT6 in solitary fibrous tumor, FOSB rearrangements in epithelioid hemangioma and pseudomyogenic hemangioendothelioma, and SUZ12 or EED mutations in malignant peripheral nerve sheath tumor, leading to loss of H3K27 trimethylation). In this review, we highlight the major changes to the soft tissue chapter in the 2020 World Health Organization Classification, as well as the new chapter on undifferentiated small round cell sarcomas, with a focus on updates in diagnostic categories, prognostication, and novel markers. Recent discoveries in molecular genetics are also discussed, particularly those of immediate utility in differential diagnosis, including protein correlates detectable using immunohistochemistry.

Paratesticular liposarcoma: Two case reports

BACKGROUND

Paratesticular liposarcoma accounts for approximately 7% of scrotal tumors. They are rare lesions of the reproductive system with approximately 90% of the lesions originating from the spermatic cord. Surgery, with the goal of complete resection, is the mainstay for treatment of this disease. However, treatment consisting of extended resection to decrease local recurrence remains controversial.

CASE SUMMARY

We report the cases of two patients with paratesticular liposarcomas who were treated with radical testicular tumor resection without adjuvant therapy. Follow-up investigations at 9 mo showed no sign of recurrence.

CONCLUSION

Surgery is the first-line treatment, regardless of whether it is a recurrent or primary tumor. Extended resection carries a higher risk of complications and should not be performed routinely. Preoperative radiotherapy can reduce the local recurrence rate without affecting the overall survival.

Primary dedifferentiated Liposarcoma of vagina: a first case report

BACKGROUND

Dedifferentiated liposarcoma, one of the most deadly types of soft tissue sarcoma, is an aggressive and high-grade form of liposarcoma. Liposarcoma occurs most commonly in the retroperitoneum, extremities and trunk, but less frequently in the female genital tract. The vagina is a very rare site of origin. Herein we report the first case of dedifferentiated Liposarcoma deriving from vagina and discuss its clinical course.

CASE PRESENTATION

A 38-year-old female patient presented to our institution with a painless vaginal mass. Abdominal computed tomography showed a 17.6 cm× 10.4 cm solid mass originating from the right lateral wall of her vagina. Then she underwent complete surgical resection of the tumor mass, and postoperative pathological result confirmed the diagnosis of dedifferentiated liposarcoma deriving from vagina. Six courses of combination chemotherapy with pirarubicin plus ifosfamide were performed after surgery. The patient remains with no evidence of disease recurrence with 13 months of follow-up.

CONCLUSIONS

Liposarcoma is very rare in female genital tract, and more rare for dedifferentiated liposarcoma in gynecologic field. Little is known about the clinical characteristics, pathological diagnosis, prognosis and optimal management strategy of vaginal dedifferentiated liposarcoma. Complete surgical resection followed by systemic chemotherapy is suggested to be standard treatment for dedifferentiated liposarcoma. Combination chemotherapy with pirarubicin and ifosfamide may be effective for treating vaginal dedifferentiated liposarcoma.

A Proposed Staging System for Improved Prognostication of MDM2-amplified Liposarcoma

Despite the release of anatomic site-specific staging systems for soft tissue sarcomas in the eighth edition of the American Joint Committee on Cancer (AJCC) Cancer Staging Manual, the algorithms for sarcomas arising in the extremities/trunk and retroperitoneum differ only in the staging of lymph node metastasis. The retroperitoneum not only provides a larger potential space for tumor growth before the clinical presentation, but its anatomic complexities complicate surgical resection and adversely affect disease-free survival. Here, we propose a new staging system for MDM2-amplified liposarcomas (well-differentiated and dedifferentiated subtypes) that properly emphasizes retroperitoneal localization, degree of differentiation (histologic subtype), and presence of distant metastasis. A retrospective cohort of 4146 adult patients with surgically resected liposarcoma was extracted from the SEER database to compare the natural history of MDM2-amplified liposarcomas arising in the extremities/trunk or retroperitoneum. Separate training and validation datasets were created, and Cox proportional hazard regression, multivariable nonlinear regression, and nomographic analyses determined the most significant parameters in predicting sarcoma-specific death. A new staging system was derived and its predictive accuracy was compared with the AJCC, eighth edition system using areas under receiver operating characteristic curves and multiple concordance indices. Multivariable analysis showed that dedifferentiation (hazard ratio [HR]=3.7±0.5; P<0.0005), retroperitoneal location (HR=3.2±0.5; P<0.0005), and distant metastasis (HR=2.4±0.6; P=0.002), but not categorized tumor size (pT category), had the largest effects on sarcoma-specific survival. A new staging system based on these predictive factors demonstrated better discrimination between tumor stages, higher concordance with clinical outcomes, and greater predictive accuracy than the AJCC eighth edition staging system (86±1% vs. 83±2%; P=0.005). Statistical analysis of a large national cohort failed to confirm that categorized tumor size is a useful criterion by which to stage MDM2-amplified liposarcoma. A simplified staging system based on anatomic location and dedifferentiation outperforms the current AJCC staging system. Anatomic localization and histologic grade, and not tumor size, should be included in any future liposarcoma-specific staging system.

Giant recurrent liposarcoma of the retroperitoneum - A surgical challenge: A case report

INTRODUCTION

Sarcomas are a rare entity with heterogeneous clinical behavior. We herein present the case of a giant retroperitoneal dedifferentiated liposarcoma and aim to remind the clinical, histological, and therapeutic features of this rare tumor.

PRESENTATION OF CASE

An 80-year-old patient was complaining of significant abdominoscrotal swelling. On physical examination, a 25-cm swelling extending from the right iliac fossa to scrotums, was observed. CT scan revealed a retroperitoneal fatty mass with necrotic areas. Ultrasonography-guided biopsy was carried. Pathological report demonstrated a dedifferentiated sarcoma. An en bloc resection of the tumor was performed through a right iliac incision extended to the scrotum. After one year of follow up, the patient had a 30-cm local recurrence. After complete resection, the patient died two days after the procedure due to neurological distress.

DISCUSSION

'Giant' liposarcomas over 20kg are extremely rare. CT-Scan and MRI are very useful for defining their size and limits. The resection of a retroperitoneal sarcoma of remarkable size is a challenge for the surgeon owing to the anatomical site that makes it hard to obtain safe margin and to the adherences with the contiguous organs. Dedifferentiated histologic subtypes and negative surgical margins are associated with poor prognosis. This explains the high rate of local recurrence after surgical excision.

CONCLUSION

In rare cases, retroperitoneal dedifferentiated liposarcomas can extend through the inguinal canal to the scrotum. Surgical resection obtaining negative margins, remains the curative treatment that reduces the risk of recurrence. Careful follow-up to detect early recurrence is essential for optimal care.

Resection outcomes for primary and local recurrent retroperitoneal liposarcoma patients

Background

The clinical characteristics of primary retroperitoneal liposarcoma (PR RPLPS) and local recurrent retroperitoneal liposarcoma (LR RPLPS) cases were compared to determine the related factors involved in postoperative survival.

Methods

A total of 90 patients who underwent surgery between 2006 and 2013 were included in this study. Clinicopathological data that was prospectively gathered was analyzed to identify factors associated with overall survival (OS) and progression-free survival (PFS).

Results

The PR cases showed a higher complete resection rate when compared to the LR group. The LR group showed a greater number that were poorly differentiated and highly malignant. More blood loss was observed in the LR compared to the PR group. Multivariate analysis suggested that blood loss and tumor grade were prognostic factors for OS and PFS of the PR group, but extent of resection was a prognostic factor only for OS. In the LR group, the extent of resection was a significant prognostic factor associated with OS, whereas tumor grade was associated with PFS.

Conclusions

Complete surgical resection is the most important factor for the survival of RPLPS patients. Tumor grade is an independent prognostic factor for PFS. In PR RPLPS, poor tumor classification and increased intraoperative bleeding are associated with a poor prognosis.

Establishment and characterization of NCC-DDLPS1-C1: a novel patient-derived cell line of dedifferentiated liposarcoma

Dedifferentiated liposarcoma (DDLPS) is one of the four subtypes of liposarcomas; it is characterized by the amplification of the 12q13-15 region, which includes MDM2 and CDK4 genes. DDLPS has an extremely high local recurrence rate and is refractory to chemotherapy and radiation, which leads to poor prognosis. Therefore, a novel therapeutic strategy should be urgently established for improving the prognosis of DDLPS. Although patient-derived cell lines are important tools for basic research, there are no DDLPS cell lines available from public cell banks. Here, we report the establishment of a novel DDLPS cell line. Using the surgically resected tumor tissue from a patient with DDLPS, we established a cell line and named it NCC-DDLPS1-C1. The NCC-DDLPS1-C1 cells contained 12q13-15, 1p32, and 1q23 amplicons and highly expressed MDM2 and CDK4 proteins. NCC-DDLPS-C1 cells exhibited constant growth, spheroid formation, aggressive invasion, and tumorigenesis in mice. By screening a drug library, we identified that the proteasome inhibitor, bortezomib, had inhibitory effects on the proliferation of NCC-DDLPS1-C1 cells. We concluded that the NCC-DDLPS1-C1 cell line may serve as a useful tool for basic and pre-clinical studies of DDLPS.

A Multi-Modality Treatment of Retroperitoneal De-Differentiated Liposarcoma

BACKGROUND Retroperitoneal sarcomas are rare tumors, only affecting 2 to 5 people per million population and accounting for 0.1% of all malignancies. Liposarcoma is the most common of all retroperitoneal sarcomas, responsible for approximately 20% of all sarcomas in adults. The most important prognostic factors are tumor grade, the presence of positive margins, tumor integrity, and degree of resection. CASE REPORT Our patient was a 73-year-old man with abdominal pain whose CT scan of the abdomen and pelvis demonstrated a 15×15 cm heterogeneous, left-sided intra-abdominal mass. He underwent resection of the retroperitoneal tumor, left colectomy, and left nephrectomy. Final pathology demonstrated a high-grade, de-differentiated liposarcoma with a rhabdosarcomatous component. The postoperative course was complicated by a small intra-abdominal abscess and abdominal dehiscence. a CT scan after surgery showed a residual tumor of the retroperitoneal posterior margin. Re-exploration to resect the residual tumor and repair the fascial dehiscence were performed. The patient underwent an initial chemotherapy regimen with doxorubicin, then moved to targeted therapy with Palbociclib, and is now on chemotherapy using Eribulin. CONCLUSIONS Achieving complete resection and the grade of the tumor at diagnosis are the 2 most important prognostic factors for patient survival in retroperitoneal liposarcoma, as survival rates are inversely proportional to the grade of the tumor. Even with the best resection attempts, there is always a risk of residual tumor cells within the tumor bed, which contribute to recurrence and need for additional surgical interventions. It is important to approach this disease process with a multidisciplinary team that includes surgical, medical, and radiation oncology to ensure the best survival outcomes. Retroperitoneal sarcoma recurrence and survival are directly related to the ability to achieve negative margins of resection, as well as the grade and size of the primary tumor. Adjuvant therapies that include radiation and immunotherapy may be effective in treating recurrent disease.

Dedifferentiated Liposarcoma: Systemic Therapy Options

OPINION STATEMENT

Over the last several years, the systemic treatment landscape for dedifferentiated liposarcoma (DDLPS) has notably expanded. Historically, systemic therapy options have been limited to cytotoxic chemotherapy agents, including doxorubicin, ifosfamide, gemcitabine, and docetaxel, that were shown to have efficacy in unselected populations of patients with soft tissue sarcomas. More recently, however, there have been phase II and III trials establishing clinical benefit of the cytotoxic agents trabectedin and eribulin along with the tyrosine kinase inhibitor pazopanib in patients with advanced liposarcoma and DDLPS. Additionally, there are several investigational targeted therapies that have incorporated advances in the understanding of DDLPS disease biology, exploiting the fact that nearly all such tumors include highly amplified expression of MDM2 and CDK4. Recent clinical trials have supported the benefit of the CDK4 inhibitor abemaciclib and the nuclear export inhibitor selinexor and support continued development of anti-MDM2 therapies, with particular attention to the bone marrow toxicity and resultant thrombocytopenia that has thus far limited their use. In contrast, the checkpoint inhibitors pembrolizumab and nivolumab remain of questionable benefit, although these immunotherapy drugs may have a role when combined with other therapeutic agents. Ongoing phase III trials will clarify the role of these novel agents. Future directions include directly comparing current standard-of-care options and newer therapies, developing synergistic combinations of novel agents, and evaluating their role in patients with localized DDLPS.

Significance of intraoperative radiation therapy and high cumulative radiation doses in retroperitoneal soft tissue sarcoma

INTRODUCTION

In retroperitoneal soft tissue sarcoma (STS) local recurrence (LR) rates remain high despite more aggressive surgical approaches. Since wide resection margins cannot be achieved in all patients, application of intraoperative radiation therapy (IORT) has been frequently discussed. Still, the significance of IORT in multimodal treatment of retroperitoneal STS remains unclear.

MATERIAL AND METHODS

Patients undergoing resection of primary or recurrent retroperitoneal STS at the University of Heidelberg Department of General, Visceral and Transplantation Surgery were retrospectively analyzed. Univariate Kaplan-Meyer and multivariate Cox regression analyses were performed to identify predictors of LR-free survival and to investigate the impact of IORT and high cumulative radiation doses. Analyses with propensity-score matched subgroups for IORT and cumulative radiation dose were performed to control for selection bias. Subgroup analyses for patients with retroperitoneal liposarcoma were likewise performed.

RESULTS

272 patients were identified. Recurrent tumors, histology of dedifferentiated liposarcoma or unclassified sarcoma and microscopically incomplete resection were associated with decreased LR-free survival. In liposarcoma, only recurrent and dedifferentiated tumors were confirmed as poor prognostic factors concerning LR. IORT and cumulative radiation doses exceeding 60 Gy did not influence LR rates (estimated 5-year LR-free survival: IORT: 39%, non-IORT: 46%; p = 0.79).

CONCLUSION

In this retrospective evaluation, additional application of IORT does not significantly influence oncological outcome in retroperitoneal soft tissue sarcoma. Randomized trials are needed to clarify the benefit of IORT.

Retroperitoneal Sarcomas: Does Laterality Matter?

BACKGROUND

Sarcomas are malignant tumors of connective tissue that can vary widely in etiology. Parameters such as grade, extent of resection, and tumor integrity have been shown to affect prognosis. Our principal aim was to examine associations between the laterality of retroperitoneal sarcomas and tumor characteristics, treatment, and patient outcomes.

MATERIALS AND METHODS

We performed a retrospective study of patients treated at our tertiary referral center with a diagnosis of primary retroperitoneal sarcoma who underwent tumor resection. Categorical variables were compared using the chi-square test, whereas continuous variables were compared using one-way analysis of variance. Cox regression was used to estimate the risk of death.

RESULTS

Data from 106 patients were analyzed. A greater proportion of bilateral or midline tumors were leiomyosarcomas (P = 0.02), whereas right-sided tumors were more likely to be liposarcoma (P = 0.02). There was no significant relationship between laterality and tumor grade or stage. Two-thirds of patients had at least one contiguous organ resected (n = 68, 65.4%). Patients with nephrectomy during sarcoma resection were more likely to have right-sided disease (P = 0.02). Splenectomy and pancreatectomy were associated with left-sided disease (P < 0.01; P < 0.01), and pancreaticoduodenectomies with bilateral or midline disease (P < 0.001). Adjusting for age, sex, race, grade, stage, histology, and treatment, there was no increased risk of death or recurrence based on laterality.

CONCLUSIONS

Although laterality did not seem to have a measurable relationship with patient outcomes or survival, there was a significant association between laterality, tumor histology, and resection of contiguous organs. These preliminary findings warrant further investigation.

A systematic review of population-based studies examining outcomes in primary retroperitoneal sarcoma surgery

Retroperitoneal sarcomas (RPS) are rare mesenchymal tumours. Their rarity challenges our ability to understand expected outcomes. The aim of this systematic review was to examine 30-day morbidity and mortality, overall survival rates and prognostic predictors from population-based studies for patients undergoing curative resection for primary RPS. A systematic literature review of EMBASE, MEDLINE, PUBMED and the Cochrane library was performed using PRISMA for population-based studies reporting from nationally registered databases on primary RPS surgical resections in adults. The main outcomes evaluated were 30-day morbidity and mortality and overall survival rates. The use of additional treatment modalities and predictors of overall survival were also examined. Fourteen studies (n = 12 834 patients) reporting from 3 national databases, (Surveillance, Epidemiology and End Results (SEER), the United States National Cancer Database (US NCDB) and the American College of Surgeons' National Surgical Quality Improvement Program (ACS NSQIP)) were analysed. The reported overall 30-day morbidity and mortality were 23% (n = 191/846) and 3% (n = 278/10 181) respectively. Reported use of perioperative radiotherapy was 28%. No study reported loco-regional recurrence rates. Overall reported 5-year survival ranged from 52% to 62%. Independent predictors of overall survival were age of the patient, resection margin, tumour grade and size, histological subtype and receipt of radiotherapy. This review of population-based data demonstrated relatively low 30-day morbidity rates in patients undergoing curative surgical resections for primary RPS. Thirty-day mortality rates were similar to other abdominal tumour groups. There remains a paucity of data reporting recurrence rates, however 5-year survival rates ranged from 52 to 62%.

Pleomorphic Sarcomas: The State of the Art

This article focuses on pleomorphic sarcomas, which are malignant mesenchymal tumors with complex genetic background at the root of their morphologic pleomorphism. They are poorly differentiated tumors that may retain different lines of differentiation, sometimes correlating with clinicopathological or prognostic features. Accurate diagnosis in this group of tumors relies on adequate sampling due to their heterogeneity and assessment with both microscopy and large panels of immunohistochemistry. Molecular analyses have a limited role in their diagnosis as opposed to translocation-related sarcomas but may provide theranostic and important prognostic information in the future.

Completion surgery of residual disease after primary inadequate surgery of retroperitoneal sarcomas can salvage a selected subgroup of patients-A propensity score analysis

BACKGROUND

Patients with retroperitoneal sarcoma (RPSs) who undergo primary inadequate surgery before referral to specialized sarcoma centers may be considered for completion surgery (CS). We wanted to compare the outcome of these patients to those who underwent primary adequate surgery (PAS) at a single referral institution.

METHODS

We identified 34 patients who were referred for CS after primary inadequate surgery. Using a propensity score based on validated RPS outcome risk factors, we managed to match 28 patients to patients with PAS.

RESULTS

Median time lag between the first and second operation in CS patients was 5 months (2-15). Surgical extent was similar among groups (median number of organs resected = 3; P = 0.08), and macroscopically complete excision was achieved in all patients. The rate of severe complications did not differ between the groups (1 of 28 vs 3 of 28, respectively; P = 0.35) and no perioperative mortality was documented. Median follow-up was 43.5 months. Patients in the CS group had similar local recurrence-free survival (mean, 92.1 ± 9.7 vs 99.8 ± 12.4; P = 0.85) and relapse-free survival (mean, 88.7 ± 9.8 vs 80.9 ± 12.3; P = 0.3) to those with PAS.

CONCLUSIONS

CS has short- and long-term outcomes comparable to PAS. While primary surgery should always be carried out at a referral institution, some of the patients who undergo an initial incomplete resection at a non specialist center can still be offered a salvage procedure at a referral institution with comparable results.

Liposarcoma: Clinico-pathological analysis, prognostic factors and survival in a series of 307 patients treated at a single institution

BACKGROUND AND OBJECTIVES

Liposarcoma (LPS) is a malignant mesenchymal tumor and the most common soft tissue sarcoma. Four different subtypes are described: well differentiated (WD) LPS or atypical lipomatous tumor (ALT), dedifferentiated (DD) LPS, myxoid LPS, and pleomorphic LPS (PLS). The objective of the study was to investigate prognostic factors and clinical outcome of liposarcoma.

METHODS

We retrospectively examined the clinico-pathological features of a series of 307 patients affected by Liposarcoma at a mean follow-up of 69 months (range 6-257). ALT/WD LPS were analyzed separately. The influence of site, size, type of presentation, grading, histotype and local recurrence on local and systemic control and survival was assessed.

RESULTS

The statistical analysis indicated that only surgical margins represented a significant prognostic factor for local recurrence in ALT/WD LPS (P = 0.0007) and other subtypes of LPS (P = 0.0055). In myxoid, PLS and DD LPS, significant prognostic factors for metastasis free survival (MFS) were surgical margins (P = 0.0009), size of the tumor (P = 0.0358), histology (P = 0.0117) and local recurrence (P = 0.0015). In multivariate analysis, surgical margins (0.0180), size (0.0432) and local recurrence (0.0288) correlated independently with MFS. Margins (P = 0.0315), local recurrence (P = 0.0482) and metastases (P < 0.0001) were prognostic factors for overall survival (OS).

CONCLUSION

Marginal surgery can be an accepted treatment for ALT/WD LPS. In other liposarcoma subtypes (Myxoid, DD, PLS) wide or radical surgery is recommended as the margins significantly influence local recurrence-free survival (LRFS), metastasis-free survival (MFS) and overall survival (OS). Local recurrence and metastases were significant prognostic factors for OS.

Subclassification of pleomorphic sarcomas: How and why should we care?

Pleomorphic sarcomas are a heterogeneous group of mesenchymal neoplasms with widely varied clinical behavior but overlapping histologic appearances. The following guidelines are helpful when approaching the diagnosis of a pleomorphic sarcoma. (1) Be aware of the relative incidence of the various sarcoma types: several pleomorphic sarcomas are relatively common (e.g., dedifferentiated liposarcoma and undifferentiated pleomorphic sarcoma), whereas others are exceptionally rare. (2) Pay attention to anatomic location: some pleomorphic sarcomas have a predilection for somatic soft tissues, especially the thigh (e.g., undifferentiated pleomorphic sarcoma, pleomorphic liposarcoma, pleomorphic rhabdomyosarcoma), whereas other pleomorphic sarcomas most often arise in the retroperitoneum (e.g., dedifferentiated liposarcoma). (3) Carefully sample the resection specimen, paying particular attention to areas with differences in gross appearances (e.g., fleshy, fibrous, mucoid, or gritty). (4) Search for histologic clues (i.e., myxoid stroma, lipoblasts, and osteoid matrix, in order to diagnose myxofibrosarcoma, pleomorphic liposarcoma, and extraskeletal osteosarcoma, respectively); these critical diagnostic features may be limited in extent. (5) Apply immunohistochemistry judiciously, after generating a differential diagnosis; always exclude metastatic sarcomatoid carcinoma and melanoma before diagnosing a pleomorphic sarcoma. This review will present an approach to the diagnosis of pleomorphic sarcomas, emphasizing differential diagnosis and the application of ancillary studies (immunohistochemistry and FISH), when relevant.

Retroperitoneal dedifferentiated liposarcoma: Analysis of 61 cases from a large institution

Background: To describe the clinical features of retroperitoneal dedifferentiated liposarcoma (RP DDLS) and further evaluate the prognostic factors.

Methods: The clinicopathological variables and treatment strategies of 61 RP DDLS patients who underwent surgical resections at a single institution between September 2005 and September 2016 were reviewed. Kaplan-Meier and Cox regression methods were conducted for survival analyses.

Results: The average patients' age was 52 years (range, 27-81), and there was almost no gender predilection (30 males vs. 31 females). 51 (83.6%) patients got gross tumor resections (R0/R1 resection), and the median tumor size was 19 cm (range, 4.3-50 cm). 39(63.9%) patients were with intermediate-grade sarcoma and 22(36.1%) were with high-grade sarcoma. The median intraoperative blood loss was 400 ml (range, 50-2700ml). 19 (31.1%) patients presented multifocal diseases. Tumors were removed intactly in 42 (68.9%) patients. In order to obtain gross tumor resections, 33 (54.1%) of the patients underwent excisions of at least one adjacent organ, of which kidney (n=21, 63.6%) was the most common one. 6 (9.8%) patients developed distant metastases during follow-up. The overall 5-year progression-free survival (PFS) rate was 3.7%, with the median PFS of 19 months. The 5-year overall survival (OS) rate was 43.5%, with the median OS of 58 months. Updating to November 2017, 30 (49.2%) patients remained alive. The median follow-up time was 49 months. Multivariate analysis using Cox proportional hazards model revealed that tumor grade, blood loss, resection extent, and tumor integrity were independently associated with OS (p=0.032, p=0.018, p=0.020, p=0.005, respectively). Tumor grade, tumor integrity and multifocality were significant predictors for PFS (p=0.013, p=0.080, p=0.009, p=0.028, respectively).

Conclusion: Intermediate-grade histology, intraoperative blood loss < 400 ml, complete tumor resection, and tumor integrity were independently associated with better OS. Intermediate-grade histology, tumor integrity and unifocal disease independently predicted favorable PFS.