The role of surgical margin status in retroperitoneal sarcoma

Radical resection and hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of high risk recurrent retroperitoneal sarcoma-A pilot study in a tertiary Asian centre

BACKGROUND

Peritoneal sarcomatosis (PS) is a difficult entity to treat with limited options and guarded prognosis. We aimed to determine if the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) could offer superior local recurrence-free survival in patients with retroperitoneal sarcoma at high risk of developing PS as opposed to extended resection alone.

METHODS

This is a single arm, phase II intervention study where all patients with recurrent localized retroperitoneal sarcoma considered at high risk of developing PS were considered for enrolment (ClinicalTrials.gov identifier: NCT03792867). Upon enrolment, patients underwent vigorous preoperative testing to ensure fitness for the procedure. During surgery, patients underwent extended resection and HIPEC with doxorubicin. Patients were followed-up every 2 weeks (± 10 days) for the first month and subsequently every three months (± 1 month) up to a year post-surgery, and were assessed for potential chemotherapy toxicity and post-treatment complications. After a year from resection and HIPEC, patients were followed-up either during routine clinic review or contacted via telephone every year (± 1 month) for 3 years.

RESULTS

Six patients were recruited but one patient dropped out due to adverse and unexpected intraoperative events. The remaining patients completed the procedure uneventfully. Post-HIPEC, all patients recurred with a disease-free interval ranging from six to 24 months. Three patients died due to complications from recurrent disease whereas the remaining three patients are alive as of their last visit. The overall survival at time at reporting ranged between 22 to 56 months.

CONCLUSION

The procedure is feasible with no major morbidity to patients. However, we are unable to recommend for it to be implemented as a routine procedure at this current stage due to lack of improved survival outcomes. Further multi-institutional studies may be conducted to yield better results.

Updated Review and Clinical Recommendations for the Diagnosis and Treatment of Patients with Retroperitoneal Sarcoma by the Spanish Sarcoma Research Group (GEIS)

Soft tissue sarcomas (STS) are an uncommon and biologically heterogeneous group of tumors arising from mesenchymal cells. The incidence is estimated at five cases per 100,000 people per year. Retroperitoneal sarcomas (RPS) account for 10-15% of all STS, and their management depends on their anatomical characteristics and histotype. Due to their very low incidence, it is recommended that RPS be treated in reference centers and evaluated by an experienced multidisciplinary team (MDT). In Spain, the Spanish Group for Research in Sarcomas (GEIS) brings together experts from various specialties to promote research on sarcomas and improve treatment results. This paper summarizes the GEIS recommendations for the diagnosis, treatment, and follow-up of patients with RPS.

Targeting the Molecular and Immunologic Features of Leiomyosarcoma

Leiomyosarcoma (LMS) is a rare, aggressive mesenchymal tumor with smooth muscle differentiation. LMS is one of the most common histologic subtypes of soft tissue sarcoma; it most frequently occurs in the extremities, retroperitoneum, or uterus. LMS often demonstrates aggressive tumor biology, with a higher risk of developing distant metastatic disease than most sarcoma histologic types. The prognosis is poor, particularly in patients with uterine disease, and there is a need for the development of more effective therapies. Genetically, LMS is karyotypically complex and characterized by a low tumor mutational burden, with frequent alterations in TP53, RB1, PTEN, and DNA damage response pathways that may contribute to resistance against immune-checkpoint blockade monotherapy. The LMS immune microenvironment is highly infiltrated with tumor-associated macrophages and tumor-infiltrating lymphocytes, which may represent promising biomarkers. This review provides an overview of the clinical and pathologic behavior of both soft tissue and uterine LMS and summarizes the genomic and immune characteristics of these tumors and how they may provide opportunities for the development of biomarker-based immune therapies.

Delayed gastric emptying after aggressive surgery for retroperitoneal sarcoma - Incidence, characteristics, and risk factors

Delayed gastric emptying (DGE) after aggressive resection of retroperitoneal sarcoma (RPS) has rarely been described. This study aimed to determine the incidence and characteristics of DGE after surgery for RPS and explore its potential risk factors. Patients with RPS who had undergone surgery between January 2010 and February 2021 were retrospectively analyzed. DGE was defined and graded according to the International Study Group of Pancreatic Surgery classification and classified as primary or secondary to other complications. Patients with clinically relevant DGE (crDGE, grade B+C) were compared to those with no or mild DGE (grade A). Multivariate logistic regression analysis of clinicopathological and surgical parameters was performed to identify risk factors for crDGE. Of the 239 patients studied, 69 (28.9%) had experienced DGE and 54 (22.6%) had experienced crDGE. Patients with primary and secondary DGE accounted approximately half and half. The most common concurrent complications included abdominal infection, postoperative pancreatic fistula, and abdominal bleeding. Patients with crDGE were more likely to have multifocal tumors and the liposarcoma subtype, with a larger tumor size, longer operating time, more resected organs, and a history of combined resection of the stomach, pancreas, small intestine, and/or colon. In multivariate analysis, the tumor size, operating time, and combined pancreatic resection were independent risk factors for crDGE. In conclusion, the current results indicated that approximately one-fourth of patients experienced DGE after aggressive surgery for RPS and that DGE was primary or secondary to other underlying conditions. A large tumor involving long, difficult surgery and combined pancreatic resection highly predicted the incidence of crDGE. The prevention and management of DGE remain challenging.

Rare presentation of retroperitoneal leiomyosarcoma mimicking a myoma in a 46-year-old woman: A case report

Retroperitoneal sarcoma is relatively uncommon. We share our experience in encountering retroperitoneal sarcoma with vascular and urethral adhesion in a 46-year-old woman. Given the rarity of these tumors, evaluation and management should ideally be performed in a center equipped with multidisciplinary expertise in treating sarcomas.

Neoadjuvant radiotherapy for resectable retroperitoneal sarcoma: a meta-analysis

BACKGROUND

Neoadjuvant radiotherapy (NRT) for resectable retroperitoneal sarcoma (RPS) has been shown to be systematically feasible. Whether NRT has equivalent or better clinical effects compared to surgery alone for RPS patients remains controversial.

METHODS

We performed a systematic literature search of PubMed, Web of Science, Embase, ASCO Abstracts, and Cochrane library databases for studies in humans with defined search terms. Articles were independently assessed by 2 reviewers, and only randomized controlled trials and cohort studies were included. The hazard ratios (HRs) of overall survival (OS), recurrence-free survival (RFS), and local recurrence (LR) were extracted from included studies. Heterogeneity among study-specific HRs was assessed by the Q statistic and I² statistic. Overall HR was assessed by random-effects or fixed-effects models. Publication bias was tested by Begg's tests, and the quality of each study was assessed with the Newcastle Ottawa Scale.

RESULTS

A total of 12 eligible studies with 7778 resectable RPS patients were finally included in this study. The pooled analysis revealed the distinct advantages of NRT as compared to surgery alone, including longer OS (HR = 0.81, P < 0.001), longer RFS (HR = 0.58, P = 0.04), and lower LR (HR = 0.70, P = 0.03). No evidence of publication bias was observed.

CONCLUSION

NRT is likely to be beneficial for resectable RPS patients in terms of OS and RFS. However, more multicenter clinical trials are needed to confirm these findings.

Abdominoinguinal approach in en bloc resection of retroperitoneal sarcoma involving iliac vessels with graft interposition

Background

Retroperitoneal sarcomas (RPSs) located in the lower abdominal quadrants involving iliac vessels are difficult to manage. This study introduced a 5-step method for en bloc resection with graft interposition using the abdominoinguinal approach and evaluated its efficacy and safety.

Methods

Data of 24 consecutive patients who met the inclusion criteria from 272 patients with RPS who underwent surgical treatment between April 2015 and April 2022 were retrospectively collected and analyzed.

Results

The patients underwent left- or right-sided abdominoinguinal incision. In all patients, the abdominoinguinal approach provided good exposure, and complete resection was achieved. Iliac artery+vein, vein, and artery resection and replacement by graft were performed in 70.8%, 25.0%, and 4.2% of patients, respectively. Additional resected organs mainly included the colon, ureter, bladder, kidney, and abdominal wall. The median number of organs resected was 5. In 37.5% of patients, reconstruction of the lower abdominal wall and inguinal ligament was performed using a mesh. Venous graft thrombosis occurred in 21.7% of patients, while no patient had pulmonary embolism or arterial occlusion. Major complications occurred in 20.8% of patients, and no 30-day mortality was observed. The estimated 5-year local recurrence and distant metastasis rates were 54.4% and 22.1%, respectively, with a median recurrence-free survival of 27 months.

Conclusions

En bloc resection of RPS involving iliac vessels with graft interposition using the abdominoinguinal approach is feasible and advantageous. Good complete resection rate and safety can be achieved. The long-term survival benefit of this surgical approach should be verified by further large-scale prospective controlled studies.

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

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

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.

Soft Tissue Sarcoma, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Soft tissue sarcomas (STS) are rare malignancies of mesenchymal cell origin that display a heterogenous mix of clinical and pathologic characteristics. STS can develop from fat, muscle, nerves, blood vessels, and other connective tissues. The evaluation and treatment of patients with STS requires a multidisciplinary team with demonstrated expertise in the management of these tumors. The complete NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Soft Tissue Sarcoma provide recommendations for the diagnosis, evaluation, and treatment of extremity/superficial trunk/head and neck STS, as well as retroperitoneal/intra-abdominal STS, desmoid tumors, and rhabdomyosarcoma. This portion of the NCCN Guidelines discusses general principles for the diagnosis and treatment of retroperitoneal/intra-abdominal STS, outlines treatment recommendations, and reviews the evidence to support the guidelines recommendations.

Impact of Surgery and Chemotherapy on Metastatic Extrauterine Leiomyosarcoma

Background: Few studies have described the characteristics and prognostic factors of patients with metastatic extrauterine leiomyosarcoma (euLMS). Therefore, we retrospectively investigated the clinicopathological features, clinical outcomes, and prognostic factors of patients with euLMS. Methods: We recruited 61 patients with metastatic euLMS treated from 2006 to 2020 and collected and statistically analyzed information on patient-, tumor-, and treatment-related factors. The median follow-up period was 21.1 months. Results: Sixty-one patients with euLMS and a median age of 59 years were included. Furthermore, their five-year overall survival (OS) rate was 38.3%. Univariate analysis revealed that primary tumor size >10 cm, synchronous metastasis, initial metastatic sites >1, and no metastasectomy with curative intent were significantly associated with poor OS rate. Multivariate analysis identified primary tumor size >10 cm as an independent prognostic factor for poor OS. Among 24 patients who received metastasectomy with curative intent, the interval from the initial diagnosis to development of metastasis ≤6 months was significantly correlated with unfavorable OS. Among 37 patients who did not receive metastasectomy, chemotherapy after metastasis development was significantly related to better OS. Conclusions: Complete metastasectomy should be considered for metastatic euLMS treatment. Moreover, chemotherapy could prolong survival in patients with metastasis who are ineligible for metastasectomy.

Macroscopically complete excision is a beneficial strategy for selected patients with peritoneal sarcomatosis

The occurrence of peritoneal sarcomatosis (PS) in patients with retroperitoneal sarcoma (RPS) indicates a poor prognosis. However, the appropriate treatment modality remains unclear. This study aimed to identify its prognostic factors and further explore the role of macroscopically complete excision (CE) in the management of PS. A retrospective database was established to evaluate patients with RPS who underwent resection between January 2011 and January 2019. Univariate and multivariate survival analyses were performed to analyze the prognostic factors and identify the population that will optimally benefit from CE. This study included a total of 49 patients with PS from 211 patients with RPS, and 34 (69.4%) patients of whom with PS underwent CE successfully. The median follow-up time was 36.0 months. There were 8 patients excluded because of loss to follow-up (n = 4) or death from complications within 90 days postoperatively (n = 4). The CE group had a marginally better prognosis compared to the macroscopically incomplete excision (IE) group (median disease-specific survival: 20 months vs. 8 months). Multivariate survival analysis demonstrated that completeness of operation (CE vs. IE) was the only independent prognostic factor in PS patients (P = 0.042). There was no significant difference in the overall complications between the CE and IE groups (P = 0.205). In conclusion, completeness of macroscopical excision is an independent prognostic predictor of PS. If technically possible, CE is a feasible strategy to improve the prognosis of selected patients with PS.

[Retroperitoneal soft tissue sarcoma: surgical management]

BACKGROUND

Retroperitoneal soft tissue sarcomas are rare and heterogeneous tumors with high recurrence rates that require a multimodal treatment approach and a surgical resection strategy adapted to tumor localization and histological subtype.

OBJECTIVE

Based on current scientific data this article intends to provide an overview on subtype-specific features, prognostic factors and operative techniques in the surgical management of retroperitoneal soft tissue sarcomas.

MATERIAL AND METHODS

A review of the literature addressing surgical management of retroperitoneal soft tissue sarcomas was performed. Current evidence and recommendations were summarized.

RESULTS AND CONCLUSION

Macroscopically complete tumor resection represents the sole curative treatment option for both primary and recurrent retroperitoneal soft tissue sarcomas. To minimize the probability of tumor-infiltrated resection margins, compartmental resection has become a standard treatment for retroperitoneal soft tissue sarcomas. This approach includes resection of all organs and structures adjacent to the tumor. Multivisceral resection is often associated with this approach and it is acceptable in terms of morbidity and mortality if performed at a center with experience in retroperitoneal sarcoma surgery. Histologic subtype, tumor grading, and quality of initial surgical treatment are major prognostic factors for oncologic overall survival.

Role of Radiation Therapy for Newly Diagnosed Retroperitoneal Sarcoma

OPINION STATEMENT

Soft tissue sarcomas (STS) are rare, aggressive, and heterogenous tumors, comprising approximately 1% of adult cancers with over 50 different subtypes. The mainstay of treatment for retroperitoneal sarcomas (RPS) includes surgical resection. The addition of radiation therapy (RT), either preoperatively or postoperatively, has been used to potentially decrease the risk of local recurrence. The recently published results from STRASS (EORTC-STBSG 62092-22092), which randomized patients to receive or not receive preoperative radiation, indicate no abdominal recurrence-free survival benefit (primary endpoint) nor overall survival benefit to date from the addition of preoperative RT prior to surgical resection in patients with RPS. Keeping in mind caveats of subgroup analyses, the data show a significant reduction in local recurrence with radiation therapy in resected patients and non-significant trends toward improved abdominal recurrence-free survival in all patients and improved local control and abdominal recurrence-free survival in patients with liposarcoma and low-grade sarcoma. Given the high rate of local failure with surgery alone, it is possible that higher RT dose and/or selective RT dose painting may improve outcomes. Prior to treatment, the authors encourage multidisciplinary review and discussion of management options at a sarcoma center for patients with RPS. Selective use of RT may be considered for patients at high risk of local recurrence.

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.

Analysis of textbook outcomes among patients undergoing resection of retroperitoneal sarcoma: A multi-institutional analysis of the US Sarcoma Collaborative

BACKGROUND

The novel composite metric textbook outcome (TO) has increasingly been used as a quality indicator but has not been reported among patients undergoing surgical resection for retroperitoneal sarcoma (RPS) using multi-institutional collaborative data.

METHODS

All patients who underwent resection for RPS between 2000 to 2016 from eight academic institutions were included. TO was defined as a patient with R0/R1 resection that discharged to home and was without transfusion, reoperation, grade ≥2 complications, hospital-stay >50th percentile, or 90-day readmission or mortality. Univariate and multivariable analyses were performed.

RESULTS

Among 627 patients, 56.1% were female and the median age was 59 years. A minority of patients achieved a TO (34.9%). Factors associated with achieving a TO were tumor size <20 cm and low tumor grade, while ASA class ≥3, history of a prior cardiac event, resection of left colon/rectum, distal pancreatic resection, major venous resection and drain placement were associated with not achieving a TO (all P < .05). Achievement of a TO was associated with improved survival (median:12.7 vs 5.9 years, P < .01).

CONCLUSIONS

Among patients undergoing resection for RPS, failure to achieve TO is common and associated with significantly worse survival. The use of TO may inform patient expectations and serve as a measure for patient-level hospital performance.

Contralateral internal iliac artery transposition for retroperitoneal sarcoma involving common iliac artery

Complete resection for retroperitoneal sarcoma (RPS) involving major vessels frequently requires vascular resection and reconstruction. The use of artificial grafts often leads to postoperative vascular graft infection (VGI), which usually requires reoperation and sometimes leads to death. In the present study, the data of RPS patients who underwent contralateral iliac artery (IIA) transposition for reconstruction of the common iliac artery (CIA) after RPS resection from 2015-2019 were retrospectively analyzed. Clinical, intraoperative, and postoperative outcomes were described. Contralateral IIA transposition was performed to reconstruct the CIA after segmental resection in three patients. All patients underwent concomitant organ resection. Colon resection was performed for all patients, nephrectomy was performed for two patients, and segmental resection of the left ureter with transurethral ureterostomy was performed for one patient. Complete resection was achieved in all patients, and microscopic tumor infiltration to the CIA was observed in all patients (tunica adventitia: 2, tunica media: 1). No major complications occurred during the hospital stay. During the follow-up period (6.0-29.1 months), one patient died from tumor recurrence, and the other two patients did not have any evidence of recurrence or metastatic disease at the latest follow-up. The level of lower limb function was favorable (MSTS93 scores: 28-30). The pelvic organ functions, including bowel, bladder, and sexual functions, were not impaired in any of the patients. This novel technique in which contralateral IIA transposition is performed to reconstruct the CIA after RPS resection is simple and reliable and may be a good alternative to artificial grafts.

Soft-tissue sarcoma in adults: An update on the current state of histiotype-specific management in an era of personalized medicine

Soft-tissue sarcomas (STS) are rare tumors that account for 1% of all adult malignancies, with over 100 different histologic subtypes occurring predominately in the trunk, extremity, and retroperitoneum. This low incidence is further complicated by their variable presentation, behavior, and long-term outcomes, which emphasize the importance of centralized care in specialized centers with a multidisciplinary team approach. In the last decade, there has been an effort to improve the quality of care for patients with STS based on anatomic site and histology, and multiple ongoing clinical trials are focusing on tailoring therapy to histologic subtype. This report summarizes the latest evidence guiding the histiotype-specific management of extremity/truncal and retroperitoneal STS with regard to surgery, radiation, and chemotherapy.

Perioperative radiotherapy versus surgery alone for retroperitoneal sarcomas: a systematic review and meta-analysis

Background

There is no clear evidence on whether radiotherapy (RT) improves treatment result in patients with retroperitoneal sarcomas (RPS).

Methods

A systematic literature search was performed using PubMed, Scopus and CENTRAL databases. Data were retrieved from published comparatives studies in patients with RPS undergoing surgery alone or RT plus surgery. The primary endpoints were the 5-year OS and the median OS. The secondary endpoints were the recurrence-free survival (RFS) and the R0-resection rate. Continuous outcomes were calculated by means of weighted mean difference (WMD).

Results

Ten out of 374 articles were analyzed. The median OS and the 5-year survival were significantly increased in patients treated with RT and surgery, compared to patients treated with surgery alone (p < 0.00001, p < 0.001). Median RFS was significantly increased in patients treated with either preoperative (p < 0.001) or postoperative (p = 0.001) RT compared to patients that underwent surgery alone. Finally, median R0-resection rate was similar between the two groups (p = 0.56).

Conclusion

RT along with radical surgery could be the standard of care in at least a subgroup of patients with RPS.

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.

Neoadjuvant radiotherapy followed by surgery compared with surgery alone in the treatment of retroperitoneal sarcoma: a population-based comparison

Introduction

Retroperitoneal sarcoma (rps) encompasses a heterogeneous group of malignancies with a high recurrence rate after resection. Neoadjuvant radiotherapy (nrt) is often used in the hope of sterilizing margins and decreasing local recurrence after excision. We set out to compare local recurrence-free survival (lrfs) and overall survival (os) in patients treated with or without nrt before resection.

Methods

Patients diagnosed with rps from February 1990 to October 2014 were identified in the Alberta Cancer Registry. Patients with complete gross resection of rps and no distant disease were included. Patient, tumour, treatment, and outcomes data were abstracted in a primary chart review. Baseline characteristics were compared using the Wilcoxon nonparametric test for continuous data and the Fisher exact test for dichotomous and categorical data. Survival was analyzed using Kaplan-Meier curves with log-rank test. Cox regression was performed to control for age, sex, tumour size, tumour grade, date of diagnosis, multivisceral resection, and intraoperative rupture.

Results

Resection alone was performed in 62 patients, and resection after nrt, in 40. Use of nrt was associated with multivisceral resection and negative microscopic margins. On univariate analysis, nrt was associated with superior median lrfs (89.3 months vs. 28.4 months, p = 0.04) and os (119.4 months vs. 75.9 months, p = 0.04). On multivariate analysis, nrt, younger age, and lower tumour grade predicted improved lrfs and os; sex, tumour size, date of diagnosis, multivisceral resection, and tumour rupture did not.

Conclusions

In this population-based study, nrt was associated with superior lrfs and os on both univariate and multivariate analysis. When feasible, nrt should be considered until a randomized controlled trial is completed.

Preoperative diagnosis and surgical treatment for giant retroperitoneal liposarcoma: A case report

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Surgery should be tailored paying attention to noble structures.

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Damage or organ involvement requires an aggressive surgery.

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Sometimes close margins are necessary to preserve critical structures.

Introduction

The purpose of this article is to present the diagnostic and surgical approach for a giant retroperitoneal sarcoma and to highlight the difficulty of a precise preoperative diagnosis and the extention of surgical resection.

Presentation of case

A 63-year-old female patient was admitted at our department with light diffuse abdominal pain, fever and gradual increase of abdominal girth. A CT scan showed a giant fatty tumor occupying left hemiabdomen and indirect findings of renal damage, probably sustained by ureter stretching and urine stasis. At surgical exploration, no cleavage plane was discovered between the mass and the surrounding organs. The severe pielonephritis and the apparent intraoperatively involvement of surrounding tumour structures lead to an aggressive surgery. An “en-bloc” resection of tumor mass, left colon, spleen, pancreatic tail, left annex, left kidney and adrenal gland was performed. Histology revealed a well differentiated liposarcoma with large areas of high grade of dedifferentiation.

Discussion

Liposarcoma is an histologic subtype of soft tissue sarcoma and the most common type of sarcoma arising in retroperitoneum. It is difficult to make an accurate preoperative diagnosis through a percutaneous biopsy. Although it is required to obtain negative resection margins, literature shows that surgical radicality is not a primary endpoint if noble structures are strictly close. In some cases surgery must be more aggressive because of the apparent organ involvement or damage.

Conclusion

This is a rare case of a giant liposarcoma involging many organs. Surgery should be tailored according to intraoperative findings and organ damage.

Variations in contents of hyaluronan in the peritumoral micro-environment of human chondrosarcoma

A concept consolidated in recent years is that tumor growth depends to a great extent on the micro-environment surrounding the tumor, which has a fundamental role in tumor progression and in determining the effectiveness of therapies. Our analysis focuses on chondrosarcoma, the second primary malignant bone tumor, resistant to both chemotherapeutic and radiation therapy. We quantified hyaluronan, one of the main components of the extracellular matrix, with the aim of comparing its amount in the connective tissue surrounding the tumor with intra-tumoral tissue and healthy fascia of the same anatomic district, viewed as a health control. We demonstrate that hyaluronan increased significantly in the peritumoral stroma compared with the healthy fascia, which showed an average amount according to the physical characteristics of body districts by a mean value of 26.9 μg/g. In the peritumoral stroma, the mean hyaluronan content reached 132.6 μg/g (mean value of 63.2 μg/g). The p-value was less than 0.01, showing a highly significant statistical difference. Surprisingly, no significant differences were detected as a function of age, gender, or tumor grade. The levels of hyaluronan were comparable in peritumoral and tumor tissues, although there were differences depending on the state of necrosis. In addition, data on the expression of hyaluronic acid synthetase showed a decrease of about 50% in peritumoral and tumor tissues, indicating alterations in hyaluronan turnover and synthesis. This work demonstrates a variation in hyaluronan contents around the chondrosarcoma, likely correlated with the aggressiveness and resistance to chemotherapy of this tumors. Statement of Clinical Significance: Deeper knowledge about the composition of the peritumoral stroma, rich in extracellular matrix, will enhance better study and understanding of the metastatic potential of tumors and their prognostic indices. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:503-509, 2019.

En bloc resection for intra-abdominal/retroperitoneal desmoid-type fibromatosis with adjacent organ involvement: A case series and literature review

Surgical treatment for intra-abdominal/retroperitoneal desmoid-type fibromatosis (IA/RPDF) is still controversial. Studies regarding en bloc resection in IA/RPDF with adjacent organ involvement are scanty. This study aims to evaluate the safety and effectiveness of en bloc resection in IA/RPDF with adjacent organ involvement. This retrospective clinical study included 21 patients who were diagnosed with IA/RPDF and underwent tumor resection at a single center between March 2013 and June 2018. All patients included in the study underwent surgery with curative intent, and IA/RPDF with adhesive organs was removed en bloc. The safety of surgical treatment was verified by the analysis of intraoperative bleeding, postoperative morbidity and perioperative mortality. The efficacy of surgical treatment was evaluated based on the status of tumor infiltration of adjacent organs and patient follow-up results. Complete macroscopic (R0 or R1) resection was achieved in all cases. A median of 2 (range, 1-7) organs were resected. The median operating time was 300 (90-650) minutes. The median intraoperative bleeding was 300 (20-4,500) milliliters. For postoperative pathological diagnosis at our center, tumor infiltrated at least one organ in each patient. Infiltration was noted in 45 resected organs (45/57, 78.9%). Grade III-V postoperative morbidity developed in one patient (4.8%). During the follow-up, one patient developed local recurrence. No DF-related death was noted during the follow-up. The 3-year disease-free survival rate was 94.1% (95% confidence interval: 83.6-100%). Therefore, en bloc resection of the tumor and involved adjacent organs is a safe and effective treatment modality for IA/RPDF.

Radiation Therapy for Retroperitoneal Sarcomas: Influences of Histology, Grade, and Size

Perioperative radiation therapy (RT) has been associated with reduced local recurrence in patients with retroperitoneal sarcomas (RPS); however, selection criteria remain unclear. We hypothesized that perioperative RT would improve survival in patients with RPS and would be associated with pathological factors. The National Cancer Database (NCDB) from 2004 to 2012 was reviewed for patients with nonmetastatic RPS undergoing curative intent resection. Tumor size was dichotomized at 15 cm based on 8th edition American Joint Committee on Cancer (AJCC) staging. Patients with the highest comorbidity score were excluded. Unadjusted Kaplan–Meier and adjusted Cox proportional hazards modeling analyzed overall survival (OS). Multivariable logistic regression modeled margin positivity. A total of 2,264 patients were included; 727 patients (32.1%) had perioperative radiation in whom 203 (9.0%) had radiation preoperatively. Median (IQR) RPS size was 17.5 [11.0–27.0] cm. Histopathology was high grade in 1048 patients (43.7%). Multivariable analysis revealed that perioperative radiation was independently associated with decreased mortality (HR 0.72, 95% confidence intervals (CIs) 0.62–0.84, p < 0.001), and preoperative RT was associated with reduced margin positivity (HR 0.72, 95% CI 0.53–0.97, p=0.032). Stratified survival analysis showed that radiation was associated with prolonged median OS for RPS that were high-grade (64.3 vs. 43.6 months, p < 0.001), less than 15 cm (104.1 vs. 84.2 months, p=0.007), and leiomyosarcomatous (104.8 vs. 61.8 months, p < 0.001). Perioperative radiation is independently associated with decreased mortality in patients with high-grade, less than 15 cm, and leiomyosarcomatous tumors. Preoperative radiation is independently associated with margin-negative resection. These data support the selective use of perioperative radiation in the multidisciplinary management of RPS.

Integrating therapies for surgical adult soft tissue sarcoma patients

Sarcomas are an uncommon group of over 50 different individual histological malignancies arising from mesenchymal (non-epithelial or connective) tissues. Overall, they constitute 1% of human malignancies with an annual incidence rate of fewer than 5 patients per million. Sarcoma may arise from any mesenchymal cell lineages including fat, muscle, or other connective tissues. Due to the rarity of these groups of malignancies, many subtypes were, and still today, are managed as a single entity. This review focused on soft tissue sarcomas with an emphasis on how to integrate therapies for patients with this rare disorder. The role for surgical resection in cure and palliation as well as the relative benefits of adjuvant therapies such as chemotherapy and radiation therapy are discussed.

Anterior Approach to En Bloc Resection in Left-Sided Retroperitoneal Sarcoma with Adjacent Organ Involvement: A Study of 25 Patients in a Single Center

Background

There is no standard surgical approach for the management of retroperitoneal sarcoma. The aim of this clinical study was to describe the experience of an anterior approach to en bloc resection in left-sided retroperitoneal sarcoma with adjacent organ involvement.

Material/Methods

This retrospective clinical study included 25 patients who were diagnosed with left-sided retroperitoneal sarcoma and underwent tumor resection at a single center between May 2012 and July 2017. All patients had tumors that were adjacent to the left colon, pancreas, left kidney, left adrenal gland, and psoas major; some of the tumors were adjacent to the diaphragm, stomach, and small intestine. An anterior approach was used to remove the left-sided retroperitoneal tumor with the adhesive organs en bloc, an approach that is described in detail. The value of this surgical approach was evaluated based on the histopathological findings, postoperative complications, and patient follow-up.

Results

The median number of resected organs, in addition to the retroperitoneal tumor, was 8 (range, 6–10). Complete macroscopic tumor resection was achieved in 23 cases (92%). Twenty-four patients (96%) had tumor infiltration of at least one organ or the surrounding fat. Three patients (12%) experienced Grade III and IV postoperative morbidities. The one-year disease-free survival rate was 91.3% among patients with macroscopically complete resections. The one-year overall survival rate was 83.2%.

Conclusions

In selected patients, left-sided retroperitoneal sarcoma associated with local organ involvement can be surgically managed using an anterior approach with en bloc resection of adjacent organs.

Soft Tissue and Uterine Leiomyosarcoma

Leiomyosarcoma (LMS) is one of the most common subtypes of soft tissue sarcoma in adults and can occur in almost any part of the body. Uterine leiomyosarcoma is the most common subtype of uterine sarcoma. Increased awareness of this unique histology has allowed for the development of drugs that are specific to LMS and has begun to shed light on the similarities and possible unique aspects of soft tissue and uterine LMS. In this review, we summarize the current understanding of the epidemiology, diagnosis, genomics, and treatment options for LMS.

Local Control of Soft Tissue and Bone Sarcomas

Sarcomas of soft tissue and bone are mesenchymal malignancies that can arise in any anatomic location, most commonly the extremity, retroperitoneum, and trunk. Even for lower grade histologic subtypes, local recurrence can cause significant morbidity and even disease-related death. Although surgery remains the cornerstone of local control, perioperative radiation and systemic therapy are often important adjuvants. This review will summarize the current therapeutic approaches for local control of soft tissue and bone sarcomas.

Comparison of retroperitoneal liposarcoma extending into the inguinal canal and inguinoscrotal liposarcoma

BACKGROUND

This study was designed to analyze differences between retroperitoneal liposarcoma (RLPS) extending into the inguinal canal and inguinoscrotal liposarcoma.

METHODS

We retrospectively reviewed the records for patients who were managed for inguinal liposarcoma at Samsung Medical Center, a tertiary hospital, between January 1998 and December 2016. Patient data on demographics, tumour location, surgery, adjuvant therapy, histology, recurrence and death were collected. We used Mann-Whitney, Fisher exact and Kaplan-Meier log-rank tests to analyze differences between groups.

RESULTS

Seven of 179 (3.9%) patients with abdominal liposarcoma had inguinoscrotal liposarcoma, and 6 of 168 (3.6%) patients with RLPS had extension to the inguinal canal. No differences were observed between groups in sex (p > 0.99), mean age (49.7 ± 6.4 yr v. 52.1 ± 12.5 yr, p = 0.37), laterality (p > 0.99) or scrotal involvement (40.0% v. 66.7%, p = 0.57). The RLPS group had significantly larger tumours than the inguinoscrotal group (27.9 ± 6.8 cm v. 7.8 ± 4.2 cm, p = 0.001). Postoperative complications were significantly more common in the RLPS group (n = 4, 83.3%); patients in the inguinoscrotal group experienced no postoperative complications (p = 0.021). Log-rank tests showed that the groups had no statistical differences in disease-free survival (p = 0.94) or overall survival (p = 0.10). However, inoperable disease-free survival was significantly poorer in the RLPS group (p = 0.010).

CONCLUSION

Although initial signs and symptoms can be similar, RLPS extending into the inguinal canal was associated with significantly higher morbidity and mortality than inguinoscrotal liposarcoma.

Imaging in retroperitoneal soft tissue sarcoma

Patients with retroperitoneal sarcoma can present to a variety of clinicians with non‐specific symptoms and retroperitoneal sarcomas can be incidental findings. Failure to recognize retroperitoneal sarcomas on imaging can lead to inappropriate management in non‐specialist centers. Therefore it is critical that the possibility of retroperitoneal sarcoma should be considered with prompt referral to a soft tissue sarcoma unit. This review guides clinicians through a diagnostic pathway, introduces concepts in response assessment and new imaging developments.

Conjunctival leiomyosarcoma: A case report and review of literature

Leiomyosarcoma is a malignant mesenchymal tumor that is very uncommon in the conjunctiva. Nevertheless, we describe here the clinical manifestations, management, and prognosis of a rare case of leiomyosarcoma in this location. An 81-year-old male presented at a tertiary hospital with a rapidly growing mass. After performing biopsy, histopathological examination revealed the existence of a conjunctival leiomyosarcoma. On this diagnosis, a thorough metastatic screening was performed showing no enlarged lymph nodes or metastatic deposits anywhere in the body. To treat the condition, we performed an evisceration with clear margins and subsequent radiotherapy.

Single-center experience with intra-abdominal liposarcoma: Optimal minimum duration for postoperative remnant tumor screening

This study sought to identify factors related to the prognosis of intra-abdominal liposarcoma and to determine the optimal minimum duration for remnant tumor screening. Intra-abdominal liposarcoma is associated with high rates of incomplete resection and recurrence requiring a sophisticated follow-up strategy.Patients who underwent surgery for intra-abdominal liposarcoma were included. Cox analyses were used to analyze factors related to recurrence and survival. To determine the optimal minimum duration for remnant tumor screening, patients with recurrence after surgery despite gross complete resection were grouped by a postoperative detection time of 1, 3, or 6 months. Their survivals were compared to the gross incomplete resection group.A total of 168 patients were included. Kaplan-Meier 5-year disease-free survival was 35.9% and overall survival was 66.5%. Multiplicity (HR=2.528, CI=1.585-4.033, P < .001), organ invasion (HR = 1.628, CI = 1.020-2.598, P = .041), and FNCLCC grades (G2,HR = 1.730, CI = 1.000-2.994; G3, HR = 3.812, CI = 2.112-6.880, P < .001) were related to recurrence. Multiplicity (HR = 2.131, CI = 1.050-4.329, P = .036), organ resection ≥3 (HR = 2.857, CI = 1.322-6.174, P = .008), gross incomplete resection (HR = 4.368, CI = 1.890-10.097, P = .001), positive margin (HR = 2.766, CI = 1.367-5.600, P = .005), FNCLCC grade (G2,HR = 2.044, CI = 0.937-4.459; G3,HR = 4.470, CI = 1.893-10.557; P = .003), and RT (HR = 0.322, CI = 0.160-0.648, P = .001) were related to overall survival. Dividing patients into 1 month (P = .097) and 3 months (P = 0.063) did not yield significant differences in univariate analyses, whereas 6 months showed significant difference (P = .015) compared to the gross incomplete resection group. Patients with tumors detected within 6 months showed similar survival to the gross incomplete resection group (HR = 0.552, CI = 0.241-1.260, P = .158), whereas patients with tumor detection after 6 months showed better survival (HR = 0.325, CI = 0.149-0.708, P = .005).In conclusion, minimum duration of 6 months for remnant tumor screening using CT seems optimal.

The modified frailty index to predict morbidity and mortality for retroperitoneal sarcoma resections

BACKGROUND

The modified frailty index (mFI) is an important method to risk-stratify surgical patients and has been validated for general surgery and selected surgical subspecialties. However, there are currently no data assessing the efficacy of the mFI to predict acute morbidity and mortality in patients undergoing surgery for retroperitoneal sarcoma.

METHODS

Using the American College of Surgeons' National Surgical Quality Improvement Program from 2007 to 2012, we performed a retrospective analysis of patients with a diagnosis of primary malignant retroperitoneal neoplasm who underwent surgical resection. The mFI was calculated according to standard published methods. Univariate and multivariate statistical analyses including χ² and logistic regression were used to identify predictors of 30-d overall morbidity, 30-d severe morbidity (Clavien III/IV), and 30-d mortality.

RESULTS

We identified 846 patients with the diagnosis of primary malignant retroperitoneal neoplasm who underwent surgical resection. The distribution mFI scores was 0 (48.5%) or 1 (36.3%), with only 4.5% of patients presenting with a score ≥3. Rates of 30-d overall morbidity, serious morbidity, and mortality were 22.6%, 12.9%, and 1.2%, respectively. Only selected mFI scores were associated with serious morbidity and overall morbidity on multivariate analysis (P < 0.05), and mFI did not predict 30-d mortality (P > 0.05).

CONCLUSIONS

Our data demonstrate that the majority of patients undergoing retroperitoneal sarcoma resections have few, if any, comorbidities. The mFI was a limited predictor of overall and serious complications and was not a significant predictor of mortality. Better discriminators of preoperative risk stratification may be needed for this patient population.

Tumor biology remains the main determinant of prognosis in retroperitoneal sarcomas: a 14-year single-center experience

AIM

To review our experience in the management of retroperitoneal sarcomas (RPSs) in a single institution, with a predominantly Asian population, and identify associated prognostic factors for overall survival (OS), disease-free survival (DFS) and local recurrence.

MATERIALS AND METHODS

All RPSs diagnosed and managed at our center between January 2000 and March 2014 were included. Exclusion criteria included patients whose medical records were untraceable and patients who underwent biopsy but did not undergo resection. The variables studied were age, gender, histological subtype, tumor size, tumor grade, surgical margins, type of presentation of tumor (primary or recurrent) and presence of contiguous organ resection. The primary outcome measured was OS.

RESULTS

Eighty-five patients underwent resection of RPS with curative intent. Eight patients underwent adjuvant chemotherapy and 15 patients underwent radiotherapy. The median DFS was 21 months (range: 0-146) and median OS was 45 months (range: 1-233). On univariate analysis, resection margin (P = 0.04), tumor grade (P = 0.011) and type of presentation of tumor (P = 0.007) were found to significantly affect OS. Patients with tumor adherent to contiguous organs had a greater OS as compared to patients with tumor invasive into the contiguous organs (P = 0.02).

CONCLUSION

An aggressive surgical approach in primary and recurrent RPS is associated with good OS. Complete resection, with contiguous organ resection if necessary should be performed to achieve microscopically negative surgical margins to allow for long-term survival. However, tumor biology remains the main determinant for OS.

Leiomiossarcoma gástrico associado a hérnia de hiato em cão da raça Shar-pei: relato de caso

RESUMO Os tumores do sistema digestório não são comuns na medicina veterinária e as neoplasias de estômago representam menos de 1% de todos os tumores malignos. O leiomiossarcoma é o segundo tumor que mais acomete o trato gastrointestinal de cães, com predisposição para as regiões de jejuno e ceco, mas qualquer porção pode ser afetada, desde o esôfago até o reto. O presente trabalho relata um caso em um canino da raça Shar-pei, macho, com 13 anos de idade e histórico de episódios eméticos pós- prandiais e emagrecimento progressivo havia oito meses. Após avaliação radiográfica e endoscópica, foi indicada intervenção cirúrgica e observada tumoração gástrica associada a hérnia de hiato. O diagnóstico de leiomiossarcoma gástrico foi estabelecido por meio de análise histopatológica. O paciente apresentou pouco tempo de sobrevida, entretanto destaca-se a raridade desse tipo de neoplasia gástrica e da associação desse tipo tumoral com hérnias de hiato, assim como a importância da análise histopatológica para o correto diagnóstico desse tipo de patologia.

Primary retroperitoneal soft tissue sarcoma: Imaging appearances, pitfalls and diagnostic algorithm

Although retroperitoneal sarcomas are rare tumours, they can be encountered by a wide variety of clinicians as they can be incidental findings on imaging or present with non specific symptoms and signs. Surgical resection can offer hope of cure and patient outcomes are improved when patients are managed in high-volume specialist centers. Failure to recognize retroperitoneal sarcomas on imaging can lead to inappropriate management in inexperienced centers. Therefore it is critical that a diagnosis of retroperitoneal sarcoma should be considered in the differential diagnosis of a retroperitoneal mass with prompt referral to a soft tissue sarcoma unit. In particular, the most common retroperitoneal sarcoma subtypes, liposarcoma and leiomyosarcoma, have characteristic imaging appearances which are discussed. This review therefore aims to set the context and guide clinicians through a diagnostic pathway for retroperitoneal masses in adults which arise extrinsic to the solid abdominal viscera.

Preoperative radiotherapy in the management of retroperitoneal liposarcoma

BACKGROUND

Histological subtype influences both prognosis and patterns of treatment failure in retroperitoneal sarcoma. Previous studies on the efficacy of neoadjuvant radiotherapy (NRT) have incorporated multiple histological types with heterogeneous tumour biology. The survival impact of NRT specifically for patients with retroperitoneal liposarcoma is poorly defined.

METHODS

Patients who underwent resection with curative intent for retroperitoneal liposarcoma and who received NRT or surgery alone were identified in the US National Cancer Data Base (2004-2013). Cox regression was used to identify co-variables associated with overall survival. NRT and surgery-alone cohorts were matched 1 : 1 by propensity scores based on the survival hazard on Cox modelling. Overall survival was compared by Kaplan-Meier estimates.

RESULTS

A total of 2082 patients with retroperitoneal liposarcoma were identified; 1908 underwent surgery alone and 174 received NRT before surgical resection. Median tumour size was 22·0 cm and 34·9 per cent of tumours were high grade. In the unmatched cohort, NRT was not associated with improved overall survival (χ²  = 3·49, P = 0·062). In the propensity score-matched cohort, NRT was associated with an improvement in survival (median overall survival 129·2 versus 84·3 months; P = 0·046; hazard ratio (HR) 1·54, 95 per cent c.i. 1·01 to 2·36). This effect appeared most pronounced for tumours with adjacent organ invasion (median overall survival not reached versus 63·8 months; P = 0·044; HR 1·79, 1·01 to 3·19).

CONCLUSION

NRT improved survival in patients undergoing surgery for retroperitoneal liposarcoma, particularly those with high-risk pathological features.

Practical Issues for Retroperitoneal Sarcoma

Background

Retroperitoneal sarcoma is rare. Using initial specimens on biopsy, a definitive diagnosis of histological subtypes is ideal but not always achievable.

Methods

A retrospective institutional review was performed for all cases of adult retroperitoneal sarcoma from 1996 to 2015. A review of the literature was also performed related to the distribution of retroperitoneal sarcoma subtypes. A meta-analysis was performed.

Results

Liposarcoma is the most common subtype (45%), followed by leiomyosarcoma (21%), not otherwise specified (8%), and undifferentiated pleomorphic sarcoma (6%) by literature review. Data from Moffitt Cancer Center demonstrate the same general distribution for subtypes of retroperitoneal sarcoma. A pathology-based algorithm for the diagnosis of retroperitoneal sarcoma is illustrated, and common pitfalls in the pathology of retroperitoneal sarcoma are discussed.

Conclusions

An informative diagnosis of retroperitoneal sarcoma via specimens on biopsy is achievable and meaningful to guide effective therapy. A practical and multidisciplinary algorithm focused on the histopathology is helpful for the management of retroperitoneal sarcoma.

The effect of microscopic margin status on survival in adult retroperitoneal soft tissue sarcomas

INTRODUCTION

Resection is the primary treatment for retroperitoneal (RP) soft tissue sarcomas (STS). Whether obtaining microscopically negative margins (R0) improves overall survival (OS) over microscopically positive margins (R1) remains unclear.

METHODS

Using the National Cancer Data Base, we identified adult patients diagnosed with RP STS after R0 or R1 resection from 1998 to 2011. We used a multivariable logistic regression model to identify clinicopathologic factors associated with margin status, including radiotherapy receipt. To assess differences in OS, the log-rank test, Cox proportional hazards regression, and propensity score matching were used.

RESULTS

We identified 4015 patients; 2593 (64.6%) underwent R0 resection and 1422 (35.4%) underwent R1 resection. The most common histology was liposarcoma (2,371, 59.1%), median age was 60 years, and median follow up was 67 months. Median OS for R0 vs. R1 patients was 92 and 70 months, respectively (log-rank p < .001). Pre-operative RT was associated with increased probability of R0 resection (68.0% vs. 57.2%, p = .012). Multivariable regression showed R0 vs. R1 resection (HR 0.70, 95% CI 0.60-0.81, p < .001) was associated with improved survival, a finding confirmed on propensity score matching. Other significant predictors of OS included low tumor grade, younger age, smaller tumor size, liposarcoma histology, and receipt of RT (HR 0.81, 95% CI 0.70-0.93, p = .016).

CONCLUSIONS

Patients who undergo R0 resection for RP STS appear to experience superior OS compared with patients who had R1 resections.

[Intra-abdominal and retroperitoneal sarcomas]

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

Preclinical Validation of the Utility of BLZ-100 in Providing Fluorescence Contrast for Imaging Spontaneous Solid Tumors

There is a need in surgical oncology for contrast agents that can enable real-time intraoperative visualization of solid tumors that can enable complete resections while sparing normal surrounding tissues. The Tumor Paint agent BLZ-100 is a peptide-fluorophore conjugate that can specifically bind solid tumors and fluoresce in the near-infrared range, minimizing light scatter and signal attenuation. In this study, we provide a preclinical proof of concept for use of this imaging contrast agent as administered before surgery to dogs with a variety of naturally occurring spontaneous tumors. Imaging was performed on excised tissues as well as intraoperatively in a subset of cases. Actionable contrast was achieved between tumor tissue and surrounding normal tissues in adenocarcinomas, squamous cell carcinomas, mast cell tumors, and soft tissue sarcomas. Subcutaneous soft tissue sarcomas were labeled with the highest fluorescence intensity and greatest tumor-to-background signal ratio. Our results establish a foundation that rationalizes clinical studies in humans with soft tissue sarcoma, an indication with a notably high unmet need.

The importance of surgical margins in retroperitoneal sarcoma

Surgery is the "gold-standard" treatment for retroperitoneal sarcomas, but local recurrence is common, and can cause disease-related death. Complete gross resection is associated with improved survival, but debate exists as to whether resection of adjacent organs to improve margins or prescription of neoadjuvant radiation leads to better outcomes. This review summarizes data addressing prognostic value of margin, extent of surgery necessary to optimize treatment of retroperitoneal sarcomas, and role of histology in optimizing therapy.