Contemporary Management of Retroperitoneal Soft Tissue Sarcomas

Leiomyosarcoma of the abdomen and retroperitoneum; a systematic review

Background

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

Methods

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

Results

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

Discussion

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

Systematic Review Registration

PROSPERO, identifier, CRD42023480527.

Three cases of retroperitoneal sarcoma in which bioabsorbable spacers (bioabsorbable polyglycolic acid spacers) were inserted prior to carbon ion radiotherapy

From August 2019 to August 2020, we inserted polyglycolic acid (PGA) spacers and administered carbon ion radiotherapy (CIRT) to three cases of retroperitoneal sarcoma at our hospital. We aimed to investigate its utility and safety for retroperitoneal sarcoma. We analyzed changes in PGA spacer volume and corresponding computed tomography (CT) values in addition to the dose distribution using in-room CT images that were obtained during treatment. We assessed adverse events and investigated the suitability, safety and effectivity of PGA spacer insertion. During treatment, changes in PGA spacer volumes and CT values were confirmed. Volumes increased in patients with a folded PGA spacer, and it increased 1.6-fold by the end of irradiation compared with planning CT. The CT values decreased by 20-50 Hounsfield units at the end of irradiation compared to the planning CT. Dose distribution evaluation showed that the dose to the gastrointestinal tract adjacent to the tumor was maintained below the tolerable dose, and a sufficient dose was delivered to the target by PGA spacer insertion. One case of subileus caused during abdominal surgery for PGA spacer insertion occurred. No other adverse events, such as digestive disorders, were observed. CIRT with PGA spacer insertion for retroperitoneal sarcomas is safe and effective. For cases in which there is no option but to perform irradiation using a PGA spacer, precautionary measures such as verification of dose distributions using CT images are necessary.

Postoperative Outcome of Surgery with Pancreatic Resection for Retroperitoneal Soft Tissue Sarcoma: Results of a Retrospective Bicentric Analysis on 50 Consecutive Patients

BACKGROUNDS

Multivisceral resection is the standard treatment for retroperitoneal sarcoma (RPS) during which pancreas resection may be necessary.

METHODS

All consecutive patients operated for RPS with pancreatectomy in 2 expert centers between 1993 and 2018 were retrospectively analyzed.

RESULTS

Fifty patients (median age: 57 years, IQR: [46-65]) with a primary (n = 33) or recurrent (n = 17) RPS underwent surgery requiring pancreas resection (distal pancreatectomy (DP) (n = 43), pancreaticoduodenectomy (PD) (n = 5), central pancreatectomy (n = 1), and atypical resection (n = 1)). Severe postoperative morbidity (Clavien-Dindo III-IV) was observed in 14 patients (28%), and 7 of them (14%) required reoperation for anastomotic bowel leakage (n = 5), gastric volvulus (n = 1), or hemorrhage (n = 1). Pancreas-related complications occurred in 25 patients (50%): 10 postoperative pancreatic fistulas (POPF) (grade A (n = 12), grade B (n = 6), grade C (n = 1)), 13 delayed gastric emptying (grade A (n = 8), grade B (n = 4), grade C (n = 1)), 1 hemorrhage (grade C). Postoperative mortality was 4% (n = 2), all following PD, caused by a massive intraoperative air embolism and by a multiple organ failure after anastomotic leakage. Pathological analysis confirmed pancreatic involvement in 17 (34%) specimens. Microscopically complete resection (R0) was achieved in 22 (44%) patients. After a follow-up of 60 months, 36 patients (75%) were still alive, among whom 27 without recurrence (56%).

CONCLUSION

Pancreatic resection during RPS surgery is associated with significant postoperative morbidity and mortality. PD should be avoided whenever possible while other procedures seemed achievable without excessive morbidity and with long-term survival.

Potential application value of PET/computed tomography in retroperitoneal leiomyosarcoma and a literature review

OBJECTIVE

To analyze the fluorine-18 fludeoxyglucose PET/computed tomography (18F-FDG PET/CT) findings of retroperitoneal leiomyosarcoma (RLMS) and the role of this method in differentiating between benign and malignant masses and classifying the malignant degree to improve the understanding of this rare disease.

METHODS

Eight leiomyomas (A group), 13 RLMSs (B group), and 20 postoperative recurrence/metastasis RLMSs (C group) were enrolled. PET/CT features of B group were analyzed. The differences of metabolic parameters between three groups were compared, receiver operating characteristic (ROC) curve analysis was performed to group A and B, and correlation analysis was performed to subgroup B.

RESULTS

(1) The RLMS patients were more likely to be female, and PET/CT showed a high degree of heterogeneous metabolism in the soft tissue mass. (2) The standardized uptake value (SUV) of RLMS were significantly higher than those of benign leiomyomas (P < 0.05). The area under the ROC curve was 0.909, the sensitivity and specificity for diagnosing RLMS were 0.923 and 0.750, respectively, The SUVmax and SUVstd of primary RLMS were moderately associated with the Ki67 index. The mean SUVmax in the G1, G2 and G3 subgroups increased successively (4.15 ± 0.35, 6.47 ± 0.83, and 10.13 ± 4.29, respectively). (3) Primary RLMS was characterized by local invasion, but hematogenous metastasis and lymph node metastasis were rare. Postoperative recurrence/metastasis of RLMS was characterized by local recurrence and hematogenous metastasis, but lymph node metastasis was rare.

CONCLUSION

PET/CT has potential value in the preoperative staging, benign and malignant differentiation, malignant degree classification and postoperative follow-up of RLMS.

Decision Making in Retroperitoneal Nerve Sheath and Nerve-Associated Tumors: A Modular Approach

BACKGROUND

Surgical treatment of retroperitoneal nerve and nerve-associated tumors is challenging, especially in cases with large extent. A single surgical access may have limitations and jeopardize patients.

OBJECTIVE

To present a series of patients to illustrate our individually tailored treatment concept and decision pathway.

METHODS

Retrospectively, clinical findings and imaging were related to surgical features and outcome. An algorithm for choice of approach was established.

RESULTS

From 2012 to 2017, we operated on n = 13 patients with retroperitoneal tumors, of these n = 9 were included (n = 6 female, n = 3 male). Histological findings included n = 2 schwannomas, n = 2 malignant peripheral nerve sheath tumors, n = 1 non-origin sarcoma, n = 1 perineurioma, n = 1 intraneural ganglion cyst, n = 1 lymphoma, and n = 1 paraganglioma. In n = 6 patients, we used a monoportal (retroperitoneal/transperitoneal) approach; in n = 2 patients, a biportal retroperitoneal to inguinal/transperitoneal to dorsal approach; and in n = 1 patient, a triportal transperitoneal to dorsal to gluteal approach. In n = 2 patients, we performed an open biopsy only; in n = 2 patients, a tumor enucleation; in n = 3 patients, a subtotal function-sparing resection; in n = 1 patient, a complete resection; and in n = 1 patient, intraneural decompression. In n = 1 patient, a new motor deficit appeared. n = 4 patients required further radio-oncological treatment. n = 8/9 patients are alive without tumor progress or recurrence.

CONCLUSION

Retroperitoneal nerve or nerve-associated tumors encompass multiple entities. Depending on suspected histology and tumor extension, extensile or combined surgical approaches may be necessary. We present our algorithm for assessment and decision-making regarding surgical access ports and pathways.

Successful Resection of a Retrohepatic Inferior Vena Cava Primary Leiomyosarcoma with Atrial Thrombus Extension in a 30-Week Pregnant Woman

Leiomyosarcomas are an uncommon malignant subset of tumors accounting for approximately 20% of soft tissue sarcomas. Primary vascular leiomyosarcomas (PVLs) are a rare subset of leiomyosarcomas that may originate in the arterial or venous circulation but most commonly affect the inferior vena cava (IVC). PVLs more commonly affect women to men in a 2:1 ratio and most frequently occur in the fourth to sixth decades of life. Few reports have described this infrequent pathologic state in the setting of advanced pregnancy. Presented is a case of a 44-year-old 30-week pregnant woman who presented with a PVL of the retrohepatic IVC, which was complicated by occlusion of the IVC and tumor thrombus extension into the hepatic veins and right atrium. Herein, we describe our multidisciplinary management of this rare problem with successful surgical resection of her tumor and IVC reconstruction.

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.

Massive retroperitoneal dedifferentiated liposarcoma in a young patient

Liposarcomas are rare malignant tumors that mostly develop in the retroperitoneum. They have a broad behavioral spectrum, from small masses of tissue to highly aggressive tumors. The dedifferentiation process occurs in up to 10% and it's most likely to occur in the retroperitoneum, a process that not only changes its components but also its prognosis. These tumors can grow to a massive size since most of them do not give any symptoms until they invade the adjacent structures. Timely detection and surgery could avoid all these potentially lethal scenarios. We present a case of a 34-year-old patient, who reported a growing mass in her abdomen that reached massive proportions but remained untreated due to lack of sufficient access to healthcare facilities in her geographic location. After complete removal of the mass the patient underwent complete recovery, dedifferentiated liposarcoma was the final diagnosis.

Retroperitoneal Leiomyosarcoma From the Radiologic Pathology Archives

Leiomyosarcoma is a malignant neoplasm that shows smooth muscle differentiation. It is the second most common sarcoma to affect the retroperitoneum. Retroperitoneal leiomyosarcomas may grow to large sizes before detection and may be an incidental finding at imaging. When symptomatic, retroperitoneal leiomyosarcoma may cause compressive symptoms, including pain. Retroperitoneal leiomyosarcoma most commonly manifests as a large soft-tissue mass, with areas of necrosis. The most frequent pattern of growth is an entirely extravascular mass. Less commonly, leiomyosarcoma may demonstrate both extravascular and intravascular components. Rarely, retroperitoneal leiomyosarcomas are completely intravascular, typically arising from the inferior vena cava. Given its variable imaging features, a large variety of neoplastic and nonneoplastic conditions are included in the differential diagnosis of retroperitoneal leiomyosarcoma. In this review, the authors discuss retroperitoneal leiomyosarcoma, with emphasis on the pathologic basis of disease, and illustrate the multimodality imaging appearances of retroperitoneal leiomyosarcoma using cases from the Radiologic Pathology Archives of the American Institute for Radiologic Pathology. The authors review important differential considerations of retroperitoneal leiomyosarcoma, focusing on the extravascular pattern of growth, and emphasize clinical and imaging features that help radiologists differentiate leiomyosarcoma from the most frequent mimics. The information presented in this review will aid radiologists in fulfilling their key roles in the diagnosis, operative planning, and follow-up of patients with retroperitoneal leiomyosarcoma.

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.

Resection of retroperitoneal sarcoma en-bloc with inferior vena cava: 20 year outcomes of a single institution

BACKGROUND

Margin negative resection offers the best chance of long-term survival in retroperitoneal sarcoma (RPS). En-bloc resection of adjacent structures, including the inferior vena cava (IVC), is often required to achieve negative margins. We review our 20-year experience of en-bloc IVC and RPS resection.

METHODS

Retrospective review of patients with RPS resection involving the IVC were matched 1:3 by age and histology to RPS without IVC resection. Prognostic factors for overall survival (OS) and disease free survival (DFS) were assessed.

RESULTS

Thirty-two patients underwent RPS resection en-bloc with IVC. They were matched with 96 cases of RPS without IVC resection. Median OS of 59 months and DFS 18 months in IVC resection group was comparable to RPS resection without vascular involvement: median OS 65 months, DFS 18 months (P = 0.519, P = 0.604). On multivariate analyses, R2 margin (OS: HR = 6.52 [95%CI: 1.18-36.09], P = 0.032) was associated with inferior OS. R2 margin and increased number of organs resected (DFS: HR = 5.07, [1.15-22.27], P = 0.031, HR = 1.28 [1.01-1.62], P = 0.014) were associated with inferior DFS. Reconstructions included graft (n = 19, 59%), patch (n = 4, 13%), primary repair (n = 6, 19%), and ligation (n = 4, 13%).

CONCLUSIONS

RPS resection en-bloc with IVC can achieve equivalent rates of DFS and OS to patients without vascular involvement.

Acute haemorrhage from a retroperitoneal liposarcoma: a rare presentation

A previously healthy 61-year-old Caucasian woman presented to the emergency department after collapsing at home with associated abdominal pain radiating to her back. An urgent CT angiogram was requested to rule out a ruptured aortic aneurysm. This showed a large 21 cm fat-containing lesion arising from the mid-pole of the left kidney, with an adjacent 4 cm perirenal haematoma. An initial diagnosis of a ruptured angiomyolipoma was made. Her haemoglobin was 105 g/L, with a creatinine of 104 mmol/L and an eGFR of 47 mL/min. Her clotting profile was normal. Following resuscitation, she was taken to the operating room and underwent an emergency open left radical nephrectomy via a left flank incision. Her recovery was uneventful and she was discharged home after 6 days. The histopathology confirmed a well-differentiated liposarcoma.

Historical perspectives and future directions in the surgical management of retroperitoneal sarcoma

Retroperitoneal sarcomas (RPS) have fascinated and intrigued physicians both past and present. Operative mortality rates were historically very high and complete resection was not possible for the majority of patients until only the last 2 decades. More recently, changes to the surgical approach and clinical decision-making in RPS have improved patient outcomes. With select integration of nonsurgical therapies, continued RPS-specific research, and ongoing collaborative efforts among major referral centers, the future appears promising.

Recent advances in the management of liposarcoma

Liposarcoma is the most common soft tissue sarcoma. With its various subtypes, the natural history of this disease can vary significantly from a locally recurrent tumor to a highly malignant one carrying a poor prognosis. Progress in the understanding of the specific molecular abnormalities in liposarcoma provides greater opportunity for new treatment modalities. Although surgical resection and radiation therapy remain the keystones for the management of primary liposarcoma, the inclusion of novel agents that target known abnormalities in advanced liposarcoma enhances the potential for improved outcomes.

Preoperative radiation therapy combined with radical surgical resection is associated with a lower rate of local recurrence when treating unifocal, primary retroperitoneal liposarcoma

BACKGROUND AND OBJECTIVES

Local recurrence (LR) is the primary cause of death in patients with retroperitoneal liposarcoma (RP-LPS). The purpose of this study was to evaluate if the addition of preoperative radiation therapy (XRT) to radical resection for RP-LPS at a single institution was associated with improved LR.

METHODS

This retrospective analysis included patients with unifocal, primary RP-LPS who underwent complete R0/R1 resection at a single institution between 1991 and 2013. Multiple patient, tumor, and surgeon characteristics were tested to evaluate their association to LR (recurrence in the retroperitoneal space). We used competing risk hazards regression to evaluate the effect of preoperative XRT on the probability of LR.

RESULTS

There were 41 patients with liposarcoma histology whose tumors included entirely well-differentiated (N = 13), de-differentiated components (n = 26), myxoid (n = 1), and NOS (n = 1). Preoperative XRT was significantly associated with a lower probability of LR (HR 0.11, 95%CI 0.01-0.91, P = 0.04) and a higher 5-year local recurrence-free survival (95.6%, 95%CI 72.4-99.4%, vs. 75.0%, 95%CI 40.8-91.2%; P = 0.0213), but not with 5-year distant recurrence-free survival or disease-specific survival.

CONCLUSIONS

Preoperative XRT combined with complete R0/R1 resection for unifocal, primary RP-LPS was associated with improved LR and it should be considered in the multimodality treatment of RP-LPS. J. Surg. Oncol. 2016;114:814-820. © 2016 2016 Wiley Periodicals, Inc.

Hypothesis: The Intratumoral Immune Response against a Cancer Progenitor Cell Impacts the Development of Well-Differentiated versus Dedifferentiated Disease in Liposarcoma

Well-differentiated/dedifferentiated (WD/DD) liposarcoma is a rare malignancy of adipocyte origin (“fat cancer”). Tumors may be entirely WD, WD with a DD component, or rarely DD without a clear WD component. WD tumors are low grade and generally indolent, while tumors with a DD component are high grade and behave much more aggressively, with a modest potential for distant metastasis. The presence of cancer progenitor cells in WD/DD liposarcoma is suggested by clinical evidence and reported research findings. In addition, there are emerging data to support the existence of a naturally occurring, antigen-driven, and adaptive immune response within the tumor microenvironment. We hypothesize that the intratumoral immune response is directed against a cancer progenitor cell and that the outcome of this response impacts the development of WD versus DD disease. Further study will likely provide interesting insights into the disease biology of WD/DD liposarcoma that may be readily translated to other more common cancers.

Long-term outcomes in treatment of retroperitoneal sarcomas: A 15 year single-institution evaluation of prognostic features

BACKGROUND

Retroperitoneal sarcomas are connective tissue tumors arising in the retroperitoneum. Surgical resection is the mainstay of treatment. Debate has arisen over extent of resection, changes in histological classification/grading, and interest in incorporating radiotherapy. Therefore, we reviewed our institution's experience to evaluate prognostic factors.

METHODS

Retrospective chart review of all primary RPS patients at Johns Hopkins Hospital from 1994 to 2010. Histologic diagnosis and grading were re-evaluated with current criteria. Prognostic factors for survival, and recurrence were assessed.

RESULTS

One hundred thirty-one primary RPS patients met inclusion criteria. Median survival for patients who undergo en-bloc resection to negative margins (R0/R1) is 81.7 months. Surgical margins and grade were the most important factors for survival along with age, gender, presence of metastases and resection of ≥5 organs. Five-year survival for R0/R1 resection was 60%, similar to compartmental resection. Radiotherapy significantly decreased local recurrence (P = 0.026) on multivariate analysis. Grade in leiomyosarcomas and dedifferentiation in liposarcomas dictated patterns of local versus distal recurrence.

CONCLUSIONS

En bloc surgical resection to R0/R1 margins remains the cornerstone of therapy and provides comparable outcomes to compartmental resections. Grade remains important for prognosis, and histology dictates recurrence patterns. Radiotherapy appears promising for local control and warrants further investigation. J. Surg. Oncol. 2016;114:56-64. © 2016 Wiley Periodicals, Inc.