Outcome following resection of retroperitoneal sarcoma

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.

Significant Predictors of Postoperative Morbidity After Radical Resection of Retroperitoneal Sarcoma in a Tertiary Center

BACKGROUND

The safety of multivisceral resection of retroperitoneal sarcoma is an issue. Previous reports have investigated its associations with the pattern of resection and factors recognized mostly per operatively.

METHODS

All consecutive RPS resections from May 2015 to April 2022 were studied retrospectively with respect to adverse events. Two univariate and multivariate logistic regression analyses were performed to investigate the associations between severe adverse events and factors recognized pre- and per operatively. Associations of adverse events with overall survival (OS) and local recurrence (LR) were investigated.

RESULTS

A total of 265 surgical interventions corresponding to 251 patients were recorded (38 RPS surgeries/year). Severe postoperative adverse events (Clavien-Dindo ≥ 3) occurred in 50 patients (18.9%), 15 (5.6%) patients underwent an iterative laparotomy, and 6 patients (2.3%) died within 90 days. On multivariate analysis including all parameters known preoperatively, male sex, performance status, dedifferentiated liposarcoma histology, and low serum albumin level were found to be significant predictors of major complications, whereas the timing of surgery and preoperative treatment were not. On univariate analysis including all per operative parameters, transfusion requirement, operative time, number of digestive anastomoses, and pancreas and/or major arterial resection were found to entail higher operative risk. On multivariate analysis, only transfusion requirement was significant. There was no impact of postoperative adverse events on OS or LR.

CONCLUSIONS

The recognition of preoperative parameters that impact safety could mitigate the extent of the surgery, specifically the resection of adherent organs not overtly invaded. For the best decision, this surgery should be performed in referral centers.

Survival analysis and prognostic factors of retroperitoneal liposarcoma curative surgery in a single centre. Analysis of adjacent organ invasion between imaging and definitive histopathology

INTRODUCTION

Retroperitoneal liposarcoma (RPL) is a rare primary mesenchymal tumour that develops in retroperitoneal adipose tissue. Unlike the majority of published series, this homogeneous cohort focuses on RPL. The main purpose of this study is to evaluate the overall and recurrence-free survival of RPLs who underwent excision surgery and the prognostic factors involved.

PATIENTS AND METHODS

A total of 82 patients from a single centre, who underwent curative surgery for histologically confirmed retroperitoneal liposarcoma between 2008 and 2020, were analysed in the study. Compartmental surgical excision was advised as per the guidelines. The primary endpoints were 5 years of overall survival and recurrence-free survival. Predictable tumour invasion of adjacent organs, based on a pre-operative CT scan, was also investigated to test the correlation between pre-operative imaging and pathological data.

RESULTS

Median follow-up was 61.6 months. Five year overall survival was 71.9% [95% CI: 59.8; 80.9] and 5 year recurrence-free survival was 49% [95% CI: 36.4; 60.5]. Following multivariable analysis, the factors influencing overall survival were tumour rupture and onset of severe complications (Dindo-Clavien grade ≥3). Factors influencing recurrence-free survival were neoadjuvant radiotherapy and tumour rupture. A significant correlation (p < 0.05) was found between predicted invasion based on a CT scan of the colon, spleen, adrenal gland, posterior abdominal wall and diaphragm, and pathological invasion.

CONCLUSIONS

Curative compartmental surgery remains the gold standard treatment for RPL. This study, highlights the fact that the quality of the surgical excision is a crucial factor in patient prognosis.

Management of recurrent retroperitoneal sarcomas

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

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.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Morbidity and Mortality after Surgery for Retroperitoneal Sarcoma

Retroperitoneal sarcoma (RPS) is a rare disease with over 100 histologic types and accounts for 10-15% of all soft tissue sarcomas. Due to the rarity of RPS, sarcoma centers in Europe and North America have created the Transatlantic RPS Working Group (TARPSWG) to study this disease and establish best practices for its management. Current guidelines dictate complete resection of all macro and microscopic disease as the gold standard for patients with RPS. Complete extirpation often requires a multi-visceral resection. In addition, recent evidence suggests that en bloc compartmental resections are associated with reduced rates of local recurrence. However, this approach must be balanced by the potential for added morbidity. Strategies to mitigate postoperative complications include optimization of the patient through improved preoperative nutrition and pre-habilitation therapy, referral to a high-volume sarcoma center, and implementation of enhanced recovery protocols. This review will focus on the factors associated with perioperative complications following surgery for RPS and outline approaches to mitigate poor surgical outcomes in this patient population.

Oncologic outcomes of surgically managed primary pelvic soft tissue sarcoma; tumour biology or surgical constraints of the true pelvis?

BACKGROUND

Pelvic soft tissue sarcomas are rare. Potentially curative resection remains challenging due to anatomical constraints of true pelvis and tumour spread through various anatomical hiatus. We sought to review the oncological outcomes of surgically managed cases at our centre and determine whether outcomes differ for patients with localised (limited to pelvis) versus extensive disease (with extra-pelvic extension).

METHODS

Sixty-seven patients who underwent surgical resection with curative intent at the centre for primary, non-metastatic, WHO intermediate to high-grade soft tissue sarcoma of the true pelvis from January 2012 through January 2020 were analysed. Establishment of the extent of disease was made by review of pre-treatment imaging and surgical notes. Oncologic endpoints examined were resection margin, recurrence rate, disease-free and overall survival.

RESULTS

Rates of complete oncological resection and disease control were similar for tumours with localised or extensive disease. On logistic regression analysis, tumour grade, and a negative resection margin (R0) correlated with the risk of recurrence (p=<0.05). On further multinomial analysis, R0 resection was associated with improved local control, but not metastatic relapse (p = 0.003). 5-year local recurrence-free and distant metastasis-free survival were 61.3% and 67.1%, respectively. Five and 10-year overall survival were 64% and 36%, respectively. Age >50 years and high tumour grade were associated with a worse outcome (p < 0.05).

CONCLUSIONS

When potentially curative surgery is performed for pelvic sarcoma, disease-extent does not influence oncologic outcomes. While a complete oncologic resection determines the risk of local recurrence, tumour grade and metastatic relapse remain primary prognostic determinants for overall survival.

Unplanned reoperation after resection of retroperitoneal sarcoma: experience based on a high-volume sarcoma center

BACKGROUND

Most retroperitoneal sarcoma (RPS) operations require combined multi-organ resection, and the proportion of unplanned reoperation is high. However, there are no relevant studies on reoperation for RPS.

METHODS

Patients who underwent at least once unplanned reoperation at Shanghai Public Health Clinical Center, Fudan University, China, from August 2009 to December 2021 were retrospectively analyzed. The baseline characteristics, primary surgery, and reoperation information, postoperative complications, and survival were analyzed.

RESULTS

A total of 51 patients were included. Among them, 21 (41.2%) were male and 30 (58.8%) were female. The median age was 51 (interquartile range [IQR], 49-63) years. Most (88.3%) had a history of abdominal surgery. Dedifferentiated liposarcoma, well-differentiated liposarcoma, leiomyosarcoma, and others accounted for 50.9%, 21.6%, 15.7%, and 11.8%, respectively. The conditions of the primary operation were as follows: 35 (68.6%) patients achieved complete surgical resection, 48 patients had combined organ resection, and a median of 3 (IQR, 2-4) organs was removed, of which 5 (9.9%) were combined with pancreaticoduodenectomy. The median operative time was 330 (IQR, 245-440) min, and the median estimated blood loss was 1500 (IQR, 500-2600) ml. The median postoperative hospital stay was 42 (IQR, 23-82) days. For reoperation, the most common reasons were bleeding (31.3%), complications related to intestinal anastomosis (27.4%), and intestinal perforation (19.9%). The mortality rate after reoperation was 39.2% (20/51). Twelve (23.5%) patients underwent reoperation at least twice.

CONCLUSIONS

Unplanned reoperation among retroperitoneal sarcoma correlates with established measures of surgical quality.

Postnephrectomy outcomes following en bloc resection of primary retroperitoneal sarcoma: multicentre study

This article reports on postoperative renal function in the largest series of patients with primary retroperitoneal sarcoma undergoing nephrectomy at three high-volume sarcoma centres. Although half of patients develop chronic kidney disease of stage 3 or higher, rarely do patients develop acute renal failure requiring renal replacement therapy.

Racial and ethnic differences in abdominal soft tissue sarcoma incidence in New Zealand: a retrospective audit

BACKGROUND

Soft tissue sarcomas are a rare and heterogenous group of tumours. Anecdotally there seems to be an over representation of patients of Māori ethnicity presented at the Auckland Regional Sarcoma Multidisciplinary Meeting (MDM). To date no study has reported on ethnicity demographics of abdominal and retroperitoneal sarcoma in New Zealand. The aim of this study is to characterize the ethnicity distribution of patients discussed at the regional MDM.

METHODS

A retrospective audit was performed of patients presented at the Auckland Regional Sarcoma MDM between January 2015 and December 2020 with abdominal sarcoma. Ethnicity documentation for these patients was reviewed.

RESULTS

One hundred and twenty-four patients with intra-abdominal and retroperitoneal tumours were discussed at MDM with 61 proceeding for resection, of those 43 (70.5%) were primary tumours, 10 (16.4%) were recurrent tumours and 8 (13.1%) had metastatic disease. Liposarcoma made up 56 (45.2%) cases, Leiomyosarcoma 33 (26.6%), Other 35 (28.2%). Ethnicities for this group specifically were European 64 (51.6%), Māori 31 (25.0%), Pacific Peoples 17 (13.7%), Asian 6 (4.8%) and Other/unknown 3(2.4%). This was found to be statistically significantly different to the expected ethnicity distribution based on 2018 census data from North Island DHBs (χ²  = 19.55, p = 0.00), with Māori and Pacific Peoples being over-represented and Asian patients being under-represented. Recommendation for surgery did not appear to be related to ethnicity.

CONCLUSION

Our descriptive data shows a higher proportion of patients of Māori ethnicity discussed through the North Island regional sarcoma MDM than we would expect comparted to ethnicity distribution in the general population. It is unclear whether this represents a true difference in incidence based on ethnicity.

Prognostic implications of histological organ involvement in retroperitoneal sarcoma

BACKGROUND

The prognostic significance of histological organ involvement by retroperitoneal sarcoma subtype is unknown. The present study aimed to describe organ involvement across the subtypes, and the implications for survival.

METHODS

Patients undergoing surgery for primary retroperitoneal sarcoma at the Queen Elizabeth Hospital, Birmingham from April 2005 to September 2018 were identified retrospectively. Histological organ involvement was classed as pushing, infiltrative or neither. Univariable and multivariable Cox regression models were produced to analyse the association between histological organ involvement and both overall (OS) and recurrence-free (RFS) survival for the cohort as a whole, and by histological subtype.

RESULTS

Data were available for a total of 197 patients, of whom 171 (86.8 per cent) had at least one organ resected. Infiltrative organ behaviour was seen in 37 patients (18.8 per cent), and pushing behaviour in 67 (34.0 per cent). For the cohort as a whole, infiltration (hazard ratio (HR) 4.32, 95 per cent c.i. 2.35 to 7.93; P < 0.001), but not pushing (HR 1.62, 0.90 to 2.92; P = 0.106), was associated with significantly shorter OS, in comparisons with a group with neither of these behaviours. However, this effect was found to differ significantly by histological subtype (P = 0.009). For patients with dedifferentiated liposarcoma, there was no significant association between tumour behaviour and either OS (P = 0.508) or RFS (P = 0.313). However, in leiomyosarcoma, infiltrative behaviour was associated with shorter OS (P = 0.002), and both infiltrative (P < 0.001) and pushing (P = 0.010) behaviours were associated with shorter RFS, compared with tumours with neither behaviour. Multivariable analyses of both OS and RFS returned similar results.

CONCLUSION

The prognostic implications of organ involvement in retroperitoneal sarcoma vary by histological subtype.

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.

A Prospective Observational Study of Multivisceral Resection for Retroperitoneal Sarcoma: Clinical and Patient-Reported Outcomes 1 Year After Surgery

BACKGROUND

Primary retroperitoneal sarcoma (RPS) may require multivisceral resection (MVR). Clinical outcome (morbidity and renal function) and quality of life (QoL) are not as well reported as the oncologic outcome.

METHODS

Patients with primary RPS who underwent surgery between 2014 and 2016 were prospectively enrolled in an observational longitudinal study. At baseline, then at 4 and 12 months, the study measured Clavien-Dindo morbidity, estimated glomerular filtration rate (EGFR), EORTC QLQ-C30, QLQ-CR29, DN4 (neuropathic pain [NP]), lower-extremity functional scale (LEFS), and the brief pain inventory. The primary end point was the difference in global health status (GHS/QoL). The secondary end points were EGFR changes, difference in other QLQ-C30 scales, pain intensity, NP, and LEFS. The study is registered at ClinTrials.gov (NCT03480399).

RESULTS

Of 74 patients, 58 were evaluable. Morbidity grade 3 or higher was 24.1%, and mortality was 1.3%. After nephrectomy, the mean 1-year EGFR change was -33.9%. The GHS/QoL at baseline was 58.6 and had increased of 6.9 points at 1 year, comparable with that of the general population. A transient worsening in pain and diarrhea had recovered at 12 months. Average pain was mild and did not differ at 12 months. However, NP was found in 41.4% of the patients and was significantly associated with resection of the psoas muscle. At baseline, LEFS was already lower than the normative value, and worsening after surgery was not clinically relevant.

CONCLUSION

A QoL measure after MVR in primary RPS is complex and requires multiple tools. Whereas overall MVR is safe and associated with an improvement in GHS/QoL, chronic NP is frequent and deserves specific attention. Pre-surgery rehabilitation tracks may help to prevent or reduce chronic NP.

Renal Function After Retroperitoneal Sarcoma Resection with Nephrectomy: A Matched Analysis of the United States Sarcoma Collaborative Database

BACKGROUND

Nephrectomy often is required during en bloc resection of a retroperitoneal sarcoma (RPS) to achieve an R0 or R1 resection. The impact of nephrectomy on postoperative renal function in this patient population, who also may benefit from subsequent nephrotoxic systemic therapy, is not well described.

METHODS

The United States Sarcoma Collaborative (USSC) database was queried for patients undergoing RPS resection between 2000 and 2016. Patients with missing pre- or postoperative measures of renal function were excluded. A matched cohort was created using coarsened exact matching. Weighted logistic regression was used to control further for differences between the nephrectomy and non-nephrectomy cohorts. The primary outcomes were postoperative acute kidney injury (AKI), acute renal failure (ARF), and dialysis.

RESULTS

The initial cohort consisted of 858 patients, 3 (0.3%) of whom required postoperative dialysis. The matched cohort consisted of 411 patients, 108 (26%) of whom underwent nephrectomy. The patients who underwent nephrectomy had higher rates of postoperative AKI (14.8% vs 4.3%; p < 0.01) and ARF (4.6% vs 1.3%; p = 0.04), but no patients required dialysis postoperatively. Logistic regression modeling showed that the risk of AKI (odds ratio [OR], 5.16; p < 0.01) and ARF (OR 5.04; p < 0.01) after nephrectomy persisted despite controlling for age and preoperative renal function.

CONCLUSIONS

Nephrectomy is associated with an increased risk of postoperative AKI and ARF after RPS resection. This study was unable to statistically assess the impact of nephrectomy on postoperative dialysis, but the risk of postoperative dialysis is 0.5% or less regardless of nephrectomy status.

Strategies for care of patients with gastrointestinal stromal tumor or soft tissue sarcoma during COVID-19 pandemic: A guide for surgical oncologists

The coronavirus disease-2019 (COVID-19) pandemic is deeply impacting the accessibility of cancer patients to surgery. In resource-limited conditions, the standard of care might not be deliverable, but evidence to support alternative management strategies often exists. By revisiting available treatment options, this review provides surgical oncologists with an evidence-based framework for treating patients with gastrointestinal stromal tumor, extremity/truncal soft tissue sarcoma, and retroperitoneal sarcoma to rapidly adapt their decision-making to the constant evolution of the COVID-19 pandemic.

Severe Postoperative Complications are Associated with Impaired Survival in Primary but not in Recurrent Retroperitoneal Sarcoma

BACKGROUND

Retroperitoneal sarcoma (RPS) surgery entails multivisceral resection, which may cause postoperative complications. We assessed the effects of complications on survival to identify their predisposing factors in primary (PRPS) and recurrent (RRPS) RPS.

METHODS

We retrospectively analyzed our institutional database. Severe postoperative complications (SC) were defined as Clavien-Dindo classification ≥ 3. Predisposing factors for complications were investigated, as was their effect on long-term outcomes.

RESULTS

In total, 154 RPS resections (78 PRPS and 76 RRPS) performed between January 2008 and December 2018 were included. Neoadjuvant chemotherapy and multifocal tumors were more common in RRPS than PRPS (34.2% vs. 11.3%, P = 0.001 and 42.1% vs. 10.3%, P < 0.001, respectively). Although surgical extent in RRPS was limited compared with PRPS (weighted organ score 1 vs. 2, P = 0.01; transfusion requirement 23.6% vs. 35.8%, P = 0.04), SC and mortality rates were comparable. SC rates were 30.1% and 35.5% for PRPS and RRPS, respectively. NACT rate tended to be higher in PRPS patients with SC (20.8% vs. 7.4%, P = 0.09), whereas weighted organ score and transfusion requirement were increased in RRPS patients with SC (2 vs. 1, P = 0.01; 40.7% vs. 14.3%, P = 0.009, respectively). PRPS patients with SC had decreased overall survival (35 months, 95% confidence interval [CI] 12.2-57.7) compared with those without SC (90 months, 95% CI 71.4-108.5, P = 0.01).

CONCLUSIONS

Postoperative complications are associated with impaired outcomes in PRPS but not in RRPS. The negative effects of complications on outcomes should be factored to perioperative management.

Atypical Lipomatous Tumors: Does Our Inconsistent Terminology Have Patient Repercussions? Results of a Meta-Analysis

OBJECTIVES

Misnaming low-grade lipomatous tumors poses a clinical and medicolegal challenge, potentially subjecting patients to expensive and unnecessary surgeries. The terms atypical lipomatous tumor (ALT) and "well-differentiated" liposarcoma (WDL) have been used interchangeably in pathology reports, scholarly works and consensus recommendations, creating vagaries between low-virulence extremity tumors and retroperitoneal disease with metastatic potential.

METHODS

A systematic review was performed on all studies that reported on the local recurrence rate and metastasis of ALTs and WDLs in living human subjects. Local recurrence and metastases were compared using Fisher's Exact Test.

RESULTS

In total, 20 studies evaluated ALTs (n=936), whereas 13 studied WDLs (n=626). Mean follow-up was 6.6±2.0 years (median, 7.0 y). No metastatic disease was observed among ALTs, whereas 15 patients with WDLs (2.7%, P<0.0001) had metastases. The local recurrence rate of ALTs was significantly lower than WDLs after both marginal (15.1%, 141/936 vs. 46.0%, 288/626, P<0.0001) and wide excisions (3.3%, 2/59 in ALT vs. 17.4%, 19/109, P=0.007).

CONCLUSIONS

ALT should be reserved for extremity lesions meeting appropriate histopathologic criteria that represent nonmetastatic disease, reducing over-diagnosis, over-treatment, and patient risk.

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.

The Transplant Surgeon: An Unlikely, Yet Suitably Qualified, Member of The Complex Neuro Endocrine Multi-Disciplinary Team

Curative surgery for retro-peritoneal tumours involving vascular structures is challenging and multi-visceral resection is often required to obtain clear resection margins. Abdominal transplant surgeons have considerable experience in all aspects of visceral, vascular and retro-peritoneal surgery. Application of these skills to resect tumours involving vascular structures, and re-implant organs to preserve function is unique. We present the case of a 15- year old girl with a complex retro-peritoneal tumour which was resected en-bloc with the kidneys and vena-cava followed by auto-transplantation of the left kidney. Seven years later, the patient represented with a recurrent tumour which was successfully excised in its entirety. We discuss how innovative surgical strategies can be performed safely on an individualized basis. We highlight the importance of balancing the benefits of the ‘technically possible procedure’ with its risks, along with consideration of the outcomes of treatment and non-treatment alike.

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%.

Did outcomes improve in retroperitoneal sarcoma surgery?

In the last decades, the deeper understanding of the biological basis of the disease, along with the advances of surgical techniques and oncologic multimodal treatments, have led to an overall increase of survival of cancer patients. However, significant amelioration of the prognosis of rare and under-investigated tumors such as soft tissue sarcoma is less evident. In this review, main changes in the surgical management of retroperitoneal sarcoma (RPS) are discussed in order to figure out whether actual improvement in RPS outcome has been occurred in the last years.

Spinal Metastasis of Well-Differentiated Liposarcoma Component in Retroperitoneal Dedifferentiated Liposarcoma Treated by Minimally Invasive Surgery

Case

Generally, well-differentiated liposarcoma (WDL) has recurrence potential but lacks metastatic potential. We present a rare case of spinal metastasis of WDL component in retroperitoneal dedifferentiated liposarcoma (DDL) treated by tumor curettage and L1 laminectomy followed by percutaneous pedicle screw fixation. Histological examination showed metastasis of the WDL component of DDL. The patient was ambulatory until death.

Conclusion

To our knowledge, no case of spinal metastasis of WDL component in retroperitoneal DDL has been reported. We should carefully consider characteristics of DDLs during treatment. Minimally invasive surgery may be a powerful tool in patients with spinal metastasis.

Surgical morbidity in retroperitoneal sarcoma resection

Resection of retroperitoneal sarcoma (RPS) typically involves multivisceral resection. The morbidity of RPS resection has decreased over time despite widespread adoption of radical resection. Certain patterns of resection are associated with higher complication rates and elderly patients are at increased risk of morbidity. Administration of preoperative radiotherapy does not increase morbidity, but intraoperative and brachytherapy techniques are associated with heightened toxicities. Long-term functional outcomes and quality of life scores after RPS resection are acceptable.

Demographics, management and treatment outcomes of benign and malignant retroperitoneal tumors in Japan

OBJECTIVES

To show the demographics, type of treatment and clinical outcomes of patients with retroperitoneal tumors in Japan.

METHODS

We carried out a retrospective analysis of patients with retroperitoneal tumors treated between 2000 and 2012 at 12 university hospitals in Japan. Histology was re-evaluated using the 2013 World Health Organization classification.

RESULTS

A total of 167 patients were included in the analysis. The number of diagnosed patients increased over the 12-year study period. Liposarcoma and schwannoma were the most common histological types among intermediate/malignant and benign tumors, respectively. The intermediate/malignant tumors were larger and were more frequently found in older people. Surgical resection was the primary treatment for 151 patients. The median survival duration for patients with malignant tumors was 91 months, and was significantly shorter than that for patients with benign and intermediate tumors (P < 0.01). R2 resection was associated with significantly shorter survival than R0/R1 resection for malignant tumors (P < 0.01), but not for intermediate. Grossly complete resection of the recurrent tumors improved survival.

CONCLUSION

The number of patients diagnosed with retroperitoneal tumors increased over time. R2 resection of primary tumors was found to be associated with poor prognosis in malignant tumors, but not in intermediate tumors. Complete surgical resection of recurrent tumors was associated with a better oncological outcome.

Recurrence patterns of retroperitoneal leiomyosarcoma and impact of salvage surgery

BACKGROUND

Optimal treatment strategies for retroperitoneal leiomyosarcoma (RPLMS), particularly recurrent disease, are unknown.

METHODS

We searched the tumor registry at The University of Texas MD Anderson Cancer Center (MDACC) to identify patients with RPLMS treated between 1994 and 2013.

RESULTS

We identified 172 patients with a diagnosis of a RPLMS. Among the 85 patients who underwent complete resection included in the survival analysis, the median overall survival (OS) was 8.3 years (95% confidence interval [CI], 5.7-12.3), 5-year local recurrence rate was 21%, and 5-year distant metastasis rate was 47%. Among 114 patients who experienced recurrence, patients who underwent salvage surgery for recurrent disease had longer OS after recurrence than patients who did not undergo salvage surgery (median survival after recurrence 5.6 vs 3.3 years, 3-year OS rates after recurrence 72.6% vs 58.1%, HR 0.402 [95%CI, 0.243-0.666]; P = 0.0004). Whether salvage surgery was performed for local or distant recurrence was not associated with OS. Patients who had a longer disease-free interval (≥12 months) had better progression-free survival after salvage surgery than those who had a shorter interval (HR, 0.437 [95%CI, 0.244-0.783]; P = 0.0055).

CONCLUSIONS

We recommend that salvage surgery be considered for selected patients with local or distant recurrence of RP LMS.

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.

Clinical outcomes of tissue expanders on adjuvant radiotherapy of resected retroperitoneal sarcoma

We investigated the efficacy and safety of a tissue expander (TE) for adjuvant radiotherapy (RT) of resected retroperitoneal sarcoma (RPS).This study was conducted with 37 patients with RPS who received resection with or without TE insertion followed by RT from August 2006 to June 2012 at Samsung Medical Center. Among the 37 patients, TE was inserted in 19. The quality of TE insertion was evaluated according to the correlation of clinical target volume and retroperitoneal surface volume covered by TE and was defined as follows: excellent, ≥85%; good, 70% to 85%; fair, 50% to 70%; and poor, <50%. The median follow-up period after surgery was 47.9 months (range, 5.5-85.5 months).The quality of TE insertion was excellent in 7 (36.8%), good in 5 (26.3%), fair in 4 (21.0%), and poor in 3 (16.7%) patients. A significantly higher biologically equivalent dose (BED, α/β = 10) was used in patients who had TE insertion (median, 64.8 vs. 60.0 Gy, P = 0.01). Local control was 39.7%, and overall survival was 76.4% at 5 years. Local control was significantly higher in patients who received ≥65 Gy of BED, 100.0% in contrast to 22.8% (P = 0.01). One patient with a history of multiple tumor resections showed abdominal infection with duodenal perforation of uncertain cause but had the potential of being related to TE and/or RT. Otherwise there were no ≥grade III acute or late toxicities.TE for adjuvant RT in RPS is feasible for delivering a higher RT dose with acceptable toxicity.

[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.