Retroperitoneal soft tissue sarcomas

Rapid and Precise Diagnosis of Retroperitoneal Liposarcoma with Deep-Learned Label-Free Molecular Microscopy

The retroperitoneal liposarcoma (RLPS) is a rare malignancy whose only curative therapy is surgical resection. However, well-differentiated liposarcomas (WDLPSs), one of its most common types, can hardly be distinguished from normal fat during operation without an effective margin assessment method, jeopardizing the prognosis severely with a high recurrence risk. Here, we combined dual label-free nonlinear optical modalities, stimulated Raman scattering (SRS) microscopy and second harmonic generation (SHG) microscopy, to image two predominant tissue biomolecules, lipids and collagen fibers, in 35 RLPSs and 34 normal fat samples collected from 35 patients. The produced dual-modal tissue images were used for RLPS diagnosis based on deep learning. Dramatically decreasing lipids and increasing collagen fibers during tumor progression were reflected. A ResNeXt101-based model achieved 94.7% overall accuracy and 0.987 mean area under the ROC curve (AUC) in differentiating among normal fat, WDLPSs, and dedifferentiated liposarcomas (DDLPSs). In particular, WDLPSs were detected with 94.1% precision and 84.6% sensitivity superior to existing methods. The ablation experiment showed that such performance was attributed to both SRS and SHG microscopies, which increased the sensitivity of recognizing WDLPS by 16.0 and 3.6%, respectively. Furthermore, we utilized this model on RLPS margins to identify the tumor infiltration. Our method holds great potential for accurate intraoperative liposarcoma detection.

What is the association of preoperative biopsy with recurrence and survival in retroperitoneal sarcoma? A systematic review by the Australia and New Zealand Sarcoma Association clinical practice guidelines working party

Preoperative biopsy for retroperitoneal sarcoma (RPS) enables appropriate multidisciplinary treatment planning. A systematic review of literature from 1990 to June 2022 was conducted using the population, intervention, comparison and outcome model to evaluate the local recurrence and overall survival of preoperative biopsy compared to those that had not. Of 3192 studies screened, five retrospective cohort studies were identified. Three reported on biopsy needle tract seeding, with only one study reporting biopsy site recurrence of 2 %. Two found no significant difference in local recurrence and one found higher 5-year local recurrence rates in those who had not been biopsied. Three studies reported overall survival, including one with propensity matching, did not show a difference in overall survival. In conclusion, preoperative core needle biopsy of RPS is not associated with increased local recurrence or adverse survival outcomes.

Sigmoid Colon Intraluminal Obstruction by a Detached Recurrent Ascending Colon Liposarcoma

Primary liposarcoma of the colon is extremely rare in the literature. We present a case of a 51-year-old male patient with recurrent ascending colon liposarcoma, which caused obstructive ileus, just a few days prior to his scheduled elective operation and led us to expedite his surgery. The procedure was scheduled to be a robotic right colectomy. After finishing the operation and extracting the specimen, the tumour could not be detected; hence, an exploratory laparotomy was performed. Findings were a large tumour in the sigmoid colon, causing complete obstruction. Sigmoidectomy was performed, in order to remove the tumour. To our knowledge, this is the first case published in the literature, reporting a colonic tumour detachment, displacement and causing distal bowel occlusion. This event highlights the importance of careful intraoperative inspection in patients with known intraluminal bowel malignancies that present with signs and symptoms of obstruction and emphasises the need for further research on the risk factors for tumour detachment and subsequent bowel occlusion.

Retroperitoneal Soft Tissue Sarcoma: Emerging Therapeutic Strategies

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

The role of radiation therapy in the management of primary retroperitoneal sarcoma: A systematic review and clinical practice guidelines from the Australia and New Zealand Sarcoma Association

While surgery is the mainstay of treatment for localised retroperitoneal sarcoma, the use of radiotherapy (RT) remains controversial. This systematic review aimed to evaluate the role of RT for retroperitoneal sarcoma. A systematic review using the population, intervention, comparison, and outcome model from 1990 to 2022 identified 66 studies (a mixture of preoperative and postoperative RT); one randomised controlled trial (RCT) with two publications, 18 registry studies, and 46 retrospective studies. In the RCT of preoperative RT, there was no difference in local/abdominal recurrence. The pooled analysis of this RCT and a retrospective study showed a significant abdominal recurrence free survival benefit with preoperative RT in low grade liposarcoma. The RCT and the majority of retrospective series found RT did not improve recurrence free survival (11 of 16 no difference in combined local and distant RFS, 11 of 13 no difference in distant metastasis free survival), disease specific survival (9 of 12 studies) or overall survival (33 of 49 studies). The majority of studies found no association between RT and perioperative morbidity. In summary, preoperative RT may improve local control for low grade (well-differentiated or grades 1-2 dedifferentiated) liposarcoma, but not other histological subtypes. There is no strong evidence that perioperative RT provides an overall survival benefit. Patients with low grade retroperitoneal liposarcoma can be considered for preoperative RT to improve abdominal recurrence free survival. The rationale and level of evidence in this scenario should be carefully discussed by the multidisciplinary team with patients. RT should not be routinely recommended for other histological subtypes.

Neoadjuvant Chemotherapy in Retroperitoneal Sarcoma: A National Cohort Study

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

CT and MR Imaging of Retroperitoneal Sarcomas: A Practical Guide for the Radiologist

Primary retroperitoneal sarcomas (RPS) represent around 10-16% of all sarcomas, with liposarcomas and leiomyosarcomas being the most common subtypes. RPS have some peculiar characteristics, imaging appearances, worse prognosis, and complications compared to other locations of sarcoma. Commonly, RPS primarily present as large masses, progressively encasing adjacent structures, causing mass effect, and complications. RPS diagnosis is often challenging, and these tumors may be overlooked; however, failure to recognize RPS characteristics leads to a worse prognosis for the patients. Surgery is the only recognized curative treatment, but the anatomical constraints of the retroperitoneum limit the ability to achieve wide resection margins; therefore, these tumors have a high rate of recurrence, and require long-term follow-up. The radiologist has an important role in the diagnosis of RPS, the definition of their extent, and their follow-up. Specific knowledge of the main imaging findings is required to reach an early diagnosis, and, ultimately, to guarantee the best patient management. This article provides an overview of the current knowledge regarding cross-sectional imaging features of patients with retroperitoneal sarcomas, presenting tips and tricks to improve imaging diagnosis of RPS.

Resection of Recurrent Pelvic Soft Tissue Sarcoma: Is the Risk Worth the Reward?

INTRODUCTION

Soft tissue sarcomas (STS) of the pelvis present a surgical and oncological challenge. We investigated the outcomes of patients undergoing resection of pelvic sarcomas.

METHODS

A retrospective analysis of all patients who underwent surgical resection for STS between 2014 and 2021 at a tertiary academic referral center (n = 172). Included all patients with primary or recurrent STS which originated or extended to the pelvic cavity (n = 29).

RESULTS

The cohort was divided into primary pelvic sarcomas (n = 18) and recurrent pelvic sarcomas (rPS, n = 11). Complete R0/R1 resection was achieved in 26 patients (89.6%). The postoperative complication rate was 48.3%. The rate of major complications was 27.5%. The median time of follow-up from surgery was 12.3 months (range, 0.6-60.3 months). Disease-free survival was superior in the primary pelvic sarcomas group compared to the rPS group (P = 0.002). However, there was no significant difference in overall survival, (P = 0.52). Univariant and multivariant analyses identified rPS group (Hazard Ratio 8.68, P = 0.006) and resection margins (Hazard Ratio 6.29, P = 0.004) to be independently associated with disease-free survival.

CONCLUSIONS

We have demonstrated that achieving R0/R1 resection is feasible. Oncological outcomes are favorable for primary tumors, whereas recurrent tumors exhibit early recurrences. Consideration of resection of recurrent pelvic STS should involve a careful multidisciplinary evaluation.

Radiation Therapy for Retroperitoneal Sarcomas: A Strass-Ful Situation

Locoregional recurrence (LRR) is the predominant pattern of relapse and often the cause of death in patients with retroperitoneal sarcomas (RPS). As a result, reducing LRR is a critical objective for RPS patients. However, unlike soft tissue sarcomas (STS) of the superficial trunk and extremity where the benefits of radiation therapy (RT) are well-established, the role of RT in the retroperitoneum remains controversial. Historically, preoperative or postoperative RT, either alone or in combination with intraoperative radiation (IORT), was commonly justified for RPS based on extrapolation from the superficial trunk and extremity STS literature. However, long-awaited results were recently published from the European Organization for Research and Treatment of Cancer (EORTC) STRASS study of preoperative radiotherapy plus surgery versus surgery alone for patients with RPS; there was no statistical difference in the primary endpoint of abdominal recurrence-free survival. However, several subset analyses and study limitations complicate the interpretation of the results. This review explores and contextualizes the body of evidence regarding RT's role in managing RPS.

Lifelong Imaging Surveillance is Indicated for Patients with Primary Retroperitoneal Liposarcoma

BACKGROUND

Surveillance imaging of patients with retroperitoneal liposarcoma (RP-LPS) after surgical resection is based on a projected risk of locoregional and distant recurrence. The duration of surveillance is not well defined because the natural history of RP-LPS after treatment is poorly understood. This study evaluated the long-term risk of recurrence and disease-specific survival (DSS) for a cohort of patients with at least 10 years of progression-free survival (10yr-PFS) from their primary resection.

METHODS

The prospective University of California, Los Angeles (UCLA) Sarcoma Database identified RP-LPS patients with 10yr-PFS after initial resection. The patients in the 10yr-PFS cohort were subsequently evaluated for recurrence and DSS. The time intervals start at date of initial surgical resection. Cox proportional hazards models were used to determine factors associated with recurrence and DSS.

RESULTS

From 1972 to 2010, 76 patients with RP-LPS had at least 10 years of follow-up evaluation. Of these 76 patients, 39 (51%) demonstrated 10yr-PFS. The median follow-up period was 15 years (range 10-33 years). Among the 10yr-PFS patients, 49% (19/39) experienced a recurrence at least 10 years after surgery. Of those who experienced recurrence, 42% (8/19) died of disease. Neither long-term recurrence nor DSS were significantly associated with age, sex, tumor size, LPS subtype, surgical margin, or perioperative treatment with radiation or chemotherapy.

CONCLUSION

Patients who have primary RP-LPS treated with surgical resection ± multimodality therapy face a long-term risk of recurrence and disease-specific death unacknowledged by current surveillance imaging guidelines. Among the patients with 10yr-PFS, 49% experienced a recurrence, and 42% of those died of disease. These findings suggest a need for lifelong surveillance imaging for patients with RP-LPS.

Clinicopathologic features, prognostic factors, and outcomes of visceral sarcomas: A retrospective 12-year single-center study

Background

Visceral sarcomas are a rare form of soft tissue sarcoma. This study aimed to evaluate the survival and prognostic factors and effective treatments for visceral sarcomas.

Methods

All patients with visceral sarcoma referred to our center between January 2010 and December 2021 were retrospectively analyzed. The Kaplan-Meier method and a log-rank test were used for survival analysis.

Results

A total of 53 patients with visceral sarcoma were analyzed in this study with the median age at diagnosis of 57 (range, 24-77) years. Among them, 37 (69.8%) and 16 (30.2%) patients had localized and metastatic diseases at the initial presentation, respectively, and 44 patients underwent surgical resection. The median follow-up, event-free survival (EFS) and overall survival (OS) were 63.0 (range, 2-130), 42.0 months (95% confidence interval [CI] 10.879-73.121) and 45.0 months (95% CI 9.938-80.062), respectively. The 5-year EFS and OS rates were 44% and 46%, respectively. Univariate analysis of prognostic indicators illustrated that metastasis at presentation, surgery, surgical margin and the types of surgery were significantly associated with OS and EFS. In this study, combined chemotherapy or radiotherapy had no effects on EFS and OS.

Conclusion

Primary visceral sarcoma is an uncommon and aggressive malignant tumor with a higher rate of local recurrence. In the largest cohort of visceral sarcomas in China to date, we identified metastases at presentation, surgery, surgical margin, and the types of surgery as independent predictors of survival. The combination of chemotherapy and radiotherapy did not affect survival.

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.

Management of Locally Recurrent Retroperitoneal Sarcoma in the Adult: An Updated Consensus Approach from the Transatlantic Australasian Retroperitoneal Sarcoma Working Group

BACKGROUND

Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS.

METHODS

An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor.

RESULTS

Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS.

CONCLUSIONS

Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery.

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

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

Deep Learning Networks for Automatic Retroperitoneal Sarcoma Segmentation in Computerized Tomography

The volume estimation of retroperitoneal sarcoma (RPS) is often difficult due to its huge dimensions and irregular shape; thus, it often requires manual segmentation, which is time-consuming and operator-dependent. This study aimed to evaluate two fully automated deep learning networks (ENet and ERFNet) for RPS segmentation. This retrospective study included 20 patients with RPS who received an abdominal computed tomography (CT) examination. Forty-nine CT examinations, with a total of 72 lesions, were included. Manual segmentation was performed by two radiologists in consensus, and automatic segmentation was performed using ENet and ERFNet. Significant differences between manual and automatic segmentation were tested using the analysis of variance (ANOVA). A set of performance indicators for the shape comparison (namely sensitivity), positive predictive value (PPV), dice similarity coefficient (DSC), volume overlap error (VOE), and volumetric differences (VD) were calculated. There were no significant differences found between the RPS volumes obtained using manual segmentation and ENet (p-value = 0.935), manual segmentation and ERFNet (p-value = 0.544), or ENet and ERFNet (p-value = 0.119). The sensitivity, PPV, DSC, VOE, and VD for ENet and ERFNet were 91.54% and 72.21%, 89.85% and 87.00%, 90.52% and 74.85%, 16.87% and 36.85%, and 2.11% and -14.80%, respectively. By using a dedicated GPU, ENet took around 15 s for segmentation versus 13 s for ERFNet. In the case of CPU, ENet took around 2 min versus 1 min for ERFNet. The manual approach required approximately one hour per segmentation. In conclusion, fully automatic deep learning networks are reliable methods for RPS volume assessment. ENet performs better than ERFNet for automatic segmentation, though it requires more time.

Dosimetric comparison between carbon, proton and photon radiation for renal retroperitoneal soft tissue sarcoma recurrence or metastasis after radical nephrectomy

OBJECTIVE

To compare the dosimetric difference between various modalities in the radiation treatment for renal retroperitoneal soft tissue sarcoma recurrence or metastasis (RRSTSRM) after radical nephrectomy, and assess the dosimetric advantage on protecting the organs at risk (OARs) in the carbon and proton radiotherapy for the patients with a single kidney.

METHODS

A total of 12 patients with RRSTSRM who underwent radical nephrectomy were enrolled in this study. Carbon, proton, and photon radiotherapy were implemented for treatment planning. The prescription dose was fulfilled by simultaneously integrated boosting technique, with giving the planning target volume-1 (PTV-1) 51Gy (RBE) and planning target volume-2 (PTV-2) 60 Gy (RBE). Doses in the patient's spinal cord, stomach, duodenum, bowel, colon, and contralateral kidney were evaluated. The normal tissue complication probability (NTCP) of the duodenum, bowel, colon, and contralateral kidney was derived under Lyman-Kutcher-Burman (LKB) estimation.

RESULTS

In the carbon plans, the percentage volume of 95% prescription dose (V95%) covering PTV-1 (PTV-2) was 95.93% ± 3.42% (95.61% ± 4.26%). No significant dosimetric difference on the target was obtained between the four radiation modalities (P > .05). The percentage volume of receiving 40 Gy (RBE) [V40Gy (RBE)] in the duodenum could be reduced from 12.94% ± 15.99% in the IMRT plans to 6.36% ± 8.79% (8.44% ± 12.35%) in the carbon (proton) plans (P < .05). The V40Gy (RBE) in the bowel could be reduced from 13.48% ± 13.12% in the IMRT plans to 7.04% ± 9.32% (7.34% ± 9.89%) in the carbon (proton) plans (P < .05). The mean value of NTCP for the duodenum was 0.43 ± 0.47 (0.45 ± 0.48) by using carbon (proton) radiation. The value was 0.05 (0.03) lower than the IMRT plans on average, with a reduction of 0.20 (0.13) for the patients with lesions <5 mm away from the duodenum. The mean doses of the contralateral kidney were 0.28 ± 0.37 Gy (RBE) [0.28 ± 0.40 Gy (RBE)] in the IMCT (IMPT) plans, which was 92.43% (92.43%) lower than the value in the IMRT plans respectively (P < .05).

CONCLUSION

Compared to the conventional radiation techniques, particle radiotherapy of carbon and proton could significantly spare more OARs in the treatment for RRSTSRM after radical nephrectomy. Patients, especially those whose residuals are close to the duodenum would potentially benefit from the particle radiation therapy for RRSTSRM on the decrease in radiation-related side-effect.

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

BACKGROUNDS

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Management of Primary Retroperitoneal Sarcoma (RPS) in the Adult: An Updated Consensus Approach from the Transatlantic Australasian RPS Working Group

BACKGROUND

Retroperitoneal soft tissue sarcomas comprise a heterogeneous group of rare tumors of mesenchymal origin that include several well-defined histologic subtypes. In 2015, the Transatlantic Australasian RPS Working Group (TARPSWG) published consensus recommendations for the best management of primary retroperitoneal sarcoma (RPS). Since then, through international collaboration, new evidence and knowledge have been generated, creating the need for an updated consensus document.

METHODS

The primary aim of this study was to critically evaluate the current evidence and develop an up-to-date consensus document on the approach to these difficult tumors. The resulting document applies to primary RPS that is non-visceral in origin, with exclusion criteria as previously described. The relevant literature was evaluated and an international group of experts consulted to formulate consensus statements regarding the best management of primary RPS. A level of evidence and grade of recommendation were attributed to each new/updated recommendation.

RESULTS

Management of primary RPS was considered from diagnosis to follow-up. This rare and complex malignancy is best managed by an experienced multidisciplinary team in a specialized referral center. The best chance of cure is at the time of primary presentation, and an individualized management plan should be made based on the 29 consensus statements included in this article, which were agreed upon by all of the authors. Whenever possible, patients should be enrolled in prospective trials and studies.

CONCLUSIONS

Ongoing international collaboration is critical to expand upon current knowledge and further improve outcomes of patients with RPS. In addition, prospective data collection and participation in multi-institution trials are strongly encouraged.

Retroperitoneal Liposarcoma Presenting With Malignant Gastric Outlet Obstruction and Acute Pancreatitis: A Case Report

Dedifferentiated liposarcomas (DDLPS) are rare, high-grade malignancies that usually originate in the retroperitoneum. Frequently, they present as asymptomatic masses, abdominal distention, abdominal pain, and weight loss. They tend to grow significantly and are usually large in size at the time of diagnosis. Surgical resection is the mainstay of treatment; however, local recurrence is common. When unresectable, they can invade local structures and produce a significant mass effect on the adjacent organs. Here we present the first case of malignant gastric outlet obstruction (MGOO) and acute pancreatitis from a retroperitoneal DDLPS.

Pancreaticoduodenectomy for Retroperitoneal Sarcomas: A Mono-Institutional Experience in China

Background

En bloc resection of retroperitoneal sarcoma (RPS) with adjacent organs such as pancreatic head and duodenum is challenging for surgeons. This mono-institutional study aims to evaluate the feasibility, safety, and outcome of performing pancreaticoduodenectomy (PD) during RPS resection.

Methods

The clinical data of RPS patients who underwent PD at the Sarcoma Center of Peking University Cancer Hospital from January 2011 to December 2019 was collected and analyzed.

Results

Twenty-seven patients out of a total of 264 surgically treated RPS underwent PD. The main pathological subtype was liposarcoma. All patients received concomitant resection of a median of three additional organs (range: 1–5), including 11 patients (40.7%) who underwent inferior vena cava resection and one patient who underwent segmental superior mesenteric-portal vein resection. Microscopic tumor infiltration to the duodenum or pancreas was observed in 81.5% of patients. Major complications occurred in 40.7% of patients; the reoperation rate was 22.2%. One patient (3.7%) died from liver abscess postoperatively. During a median follow-up of 18.9 months, 15 patients (55.6%) developed locally recurrent disease; two patients (7.4%) also had pulmonary metastases additionally. Twelve patients (44.4%) died from local relapse eventually.

Conclusion

PD during RPS resection is feasible, and it may be necessary to achieve complete resection. However, considering the complexity and risk, it should be performed by an experienced surgical team. The long-term survival benefit of this procedure should be verified by further large-scale multi-institutional studies.

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

BACKGROUND AND PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Retroperitoneal soft-tissue sarcomas: Radiotherapy experience from a tertiary cancer center and review of current evidence

BACKGROUND

Surgery remains to be the main therapeutic approach for retroperitoneal sarcomas (RPS) although evidence supports that complementary radiotherapy increases local-control and survival. We present a multidisciplinary management and experience of a tertiary cancer center in the treatment of RPS and analyze current evidence of radiotherapy efficacy.

PATIENTS AND METHODS

We retrospectively reviewed 19 patients with primary or relapsed RPS treated between November 2009 and October 2018. Multidisciplinary approach comprised complete resection in 15 patients (79%) achieving resection R0 in 11 patients (58%), R1 in 4 patients (21%) and R2 in 2 patients (10%). Seven patients (37%) underwent a preoperative radiation (PRORT), 10 patients (53%), post-operative radiation (PORT) and 2 patients (10%), received radiotherapy exclusively. Ten patients (53%) received adjuvant chemotherapy.

RESULTS

With a median follow-up of 24 months (2-114 months), actuarial rates of loco-regional relapse free survival (LRFS) at 1, 2 and 3 years were 77%, 77% and 67%, respectively. Actuarial rates of distant-metastases-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) at 1, 2 and 3 years were 100%, 100% and 80% for DMFS; 94%, 77% and 67% for DFS and 100%, 91% and 91% for OS, respectively. Only surgical margins (negative vs. positive) showed significance for 3y-LRFS: 100% vs. 34.3%, p = 0.018. Treatment tolerance was acceptable with no acute or late toxicity higher than grade 2.

CONCLUSIONS

Complementary radiotherapy appears to be useful and well tolerated for the multidisciplinary management of RPS. Presence of positive surgical margins seems to be the most relevant prognostic factor through the follow-up.

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.

Soft Tissue Tumors of the Abdomen and Retroperitoneum

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

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.

An Evaluation of the Eighth Edition of the American Joint Committee on Cancer (AJCC) Staging System for Retroperitoneal Sarcomas Using the National Cancer Data Base (NCDB): Does Size Matter?

OBJECTIVES

Retroperitoneal sarcomas (RPS) are often large at diagnosis calling into question the seventh edition AJCC size classification of <5 cm (T1) or ≥5 cm (T2). The eighth edition expands T stage into 4 categories (T1: ≤5 cm, T2: 5<x≤10 cm, T3: 10<x≤15 cm, T4: >15 cm). We evaluated the prognostic ability of the eighth edition using the National Cancer Database (NCDB).

METHODS

Patients with RPS treated between 1998 and 2011 were identified from the NCDB; overall survival (OS) was compared.

RESULTS

Of the 6427 patients identified, 9% had tumors ≤5 cm (n=580), 19.4% 5<x≤10 cm (n=1246), 20.2% 10<x≤15 cm (n=1298) and 47.4% >15 cm (n=3045). With the eighth edition, stage II patients (G2/3 ≤5 cm) have a similar OS to stage IIIA patients (G2/3 5 cm<x≤10 cm), and patients with larger tumors (stage IIIB, G2/3>10 cm) show a decrease in OS. Tumor size as a continuous variable had a modest effect on survival (HR, 1.004; P=0.04). On multivariate analysis, higher T-stage was associated with decreased OS (T4 HR, 1.3; P<0.001) but high grade and incomplete resection (R2) were stronger prognostic factors. The c-index for both editions were similar (80.13 eighth vs. 80.08 seventh).

CONCLUSIONS

The eighth edition AJCC staging system for retroperitoneal sarcoma incorporates larger tumor size parameters that better characterize most patients, but tumor size alone is only a modest predictor of outcome.

Hypofractionated radiotherapy for non-metastatic bone and soft tissue sarcomas

PURPOSE

To evaluate the efficacy and toxicity of hypofractionated radiotherapy in non-metastatic soft tissue and bone sarcomas.

PATIENTS AND METHODS

Thirty patients underwent hypofractionated radiotherapy between 2007 and 2015. Overall, 17 patients underwent primary hypofractionated radiotherapy, nine underwent hypofractionated radiotherapy for reirradiation, and four received a boost dose via hypofractionated radiotherapy after external beam radiotherapy. Most common disease sites were head and neck and retroperitoneum. Hypofractionated radiotherapy was administered with a definitive, adjuvant, or neoadjuvant intent.

RESULTS

Median age was 37 years (range: 11-82 years). Median hypofractionated radiotherapy dose was 35Gy (range: 20-50Gy) in three to five fractions. Median follow-up was 21 months (range: 1-108 months). One- and 2-year overall survival rate was 75% and 52%, respectively. One- and 2-year local recurrence-free survival rate was 59% and 48%, with local recurrence rates of 16% and 33% in 1 and 2 years, respectively. Univariate analysis revealed tumour size (P=0.04), hypofractionated radiotherapy intent (P=0.016) and reirradiation (P=0.001) as prognostic factors for local recurrence-free survival. Severe late toxicity was observed in one patient as grade 3 trismus.

CONCLUSION

Hypofractionated radiotherapy as the primary treatment or for reirradiation has been shown to be safe in the treatment of bone and soft tissue sarcomas. It can provide relatively good local control and survival rates.

Impact of primary tumor location on outcome of liposarcoma patients, a retrospective cohort study

BACKGROUND

Tumor location as a prognostic factor for patients with liposarcoma (LPS) has been studied modestly with varying outcomes. The aim was to establish the impact of tumor location on recurrence and survival of LPS patients.

METHODS

A retrospective database of patients treated for LPS until December 2017 was used to assess 5-year local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) and disease-specific survival (DSS) per tumor location using the Kaplan-Meier method and log-rank test. A multivariable Cox regression analysis was performed to adjust for other prognostic factors.

RESULTS

In total, 518 patients were identified with a median follow-up of 68 months (interquartile range 31-138). Patients with retroperitoneal/intrathoracic WDLPS or DDLPS (p = 0.014), or testicular WDLPS (p = 0.026) developed a local recurrence more often than patients with other tumor locations. No differences between LPS subtypes and tumor location in the development of metastases (p = 0.600) was observed. Five-year LRFS differed significantly between tumor locations (p < 0.001) as well as 5y-DSS (p < 0.001), but 5y-DMFS did not (p = 0.241), with retroperitoneal/intrathoracic LPS having a worse prognosis. Patients with WDLPS in the extremity, trunk or testicular region did not die of disease, except for the rare occasion of dedifferentiation upon recurrence. After adjustment for other prognostic factors, tumor location was only of prognostic value for DSS (retroperitoneal/intrathoracic vs. extremity: HR 5.08, 95% CI 2.41-10.71, p < 0.001).

CONCLUSION

For all tumor locations, DSS mimicked DMFS except for retroperitoneal/intrathoracic LPS, where DSS mimicked LRFS and where DSS was worse than DMFS. This implies that these patients die of local disease instead of metastatic disease.

A sub-Saharan African experience in the surgical management of soft tissue sarcomas in an oncology unit in: a retrospective cohort study

INTRODUCTION

Soft tissue sarcomas (STS) consist of over 70 histologic subtypes and constitute only 1% of adult malignancies. The fulcrum of management is surgical resection with neoadjuvant or adjuvant treatment-chemoradiation.

METHODS

The study is a retrospective review of consecutive STS patients who had surgery at the University College Hospital, Ibadan, between October 2007-2017. Data extraction was from the admission and operative registers, theatre records and histology reports. Statistical analysis was done using the Statistical Package for Social Sciences (SPSS) version 20 (Chicago IL USA). Results were summarized as charts and graphs.

RESULTS

Five hundred and ninety six cases of STS were seen over the ten-year period. Of these, 383 (64.3%) patients had surgery and the case files of 326 (85.1%) of these patients was available for review. The duration of soft tissue swelling, ranged from 1-96 months. A third of the tumors were superficial while 68% were deep-seated. Oncoplastic reconstruction was done in 42(13%) patients. The resection margin was negative in 88%. A total of 202 patients were followed up regularly for between 24-36 months only.

CONCLUSION

Patients who benefitted from definitive surgical treatment for STS were found to be the young and middle age group. These patients had extended duration of symptoms with lesions > 5cm in size. Truncal and visceral STS had the worst prognosis. A Multi-Disciplinary Tumor (MDT) board for STS and a robust follow up would enhance the management of STS in a low resource setting.

Optimal maximum duration for delaying salvage operation when recurrence of retroperitoneal liposarcoma is suspected: a single-center study

BACKGROUND

This study was designed to identify the optimal maximum duration for delaying salvage operation when recurrence of retroperitoneal liposarcoma (LPS) is suspected.

METHODS

Patients who underwent salvage operation at Samsung Medical Center for recurrent retroperitoneal LPS from January 2000 to December 2015 were reviewed. The time interval between recurrence and operation for recurrence was divided by 1, 2 or 3 months. A Cox proportional-hazards model was used to analyze factors related to disease-free survival along with recurrence-to-operation interval divided by 1, 2 or 3 months.

RESULTS

The 1-, 3-, and 5-year disease-free survival rates were 43.2%, 15.6% and 13.4%, respectively. FNCLCC grade (p = 0.023) and recurrence-to-operation interval divided by 3 months (p = 0.003) were significant factors associated with recurrence. FNCLCC grade 2 (HR 1.940, CI 0.935-4.026, p = 0.238) and grade 3 (HR 4.049, CI 1.767-9.281, p = 0.007) showed increased risk compared to grade 1. Patients who underwent salvage operation more than 3 months after recurrence showed significantly increased risk of recurrence compared to patients within 3 months (HR 2.724, CI 1.391-5.337, p = 0.003).

CONCLUSIONS

Based on our analysis of recurrence-free survival, salvage operation can be delayed for less than 3 months when recurrence is suspected. A short-term follow-up imaging study should be performed within this period.

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.

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.

Radical Nephrectomy for Primary Retroperitoneal Liposarcoma Near the Kidney has a Beneficial Effect on Disease-Free Survival

BACKGROUND

The purpose of this study is to analyze the clinical impact of radical nephrectomy on retroperitoneal liposarcoma near the kidney.

METHODS

Data of patients who underwent surgery for unilateral primary retroperitoneal liposarcoma near the kidney were retrospectively collected. Patients were divided into four groups according to whether they underwent nephrectomy and combined resection of other organs. Kaplan-Meier survival analysis was used to estimate disease-free survival and overall survival. Multivariable Cox analysis was used to analyze factors related to disease-free survival and overall survival.

RESULTS

Nephrectomy (HR = 0.260, CI = 0.078-0.873, p = 0.029) had a beneficial effect on disease-free survival, while interaction model of nephrectomy*other organ resection (HR = 4.655, CI = 1.767-12.263, p = 0.002) showed poor disease-free survival. Other organ resection was not related to disease-free survival (HR = 1.543, CI = 0.146-16.251, p = 0.718). Operation method (p = 0.007) and FNCLCC grade (p < 0.001; G2, HR = 1.833, CI = 0.684-4.915, p = 0.228; G3, HR = 9.190, CI = 3.351-25.199, p < 0.001) were significant factors for disease-free survival. While combined organ resection without nephrectomy group (HR = 1.604, CI = 0.167-15.370, p = 0.682) and radical nephrectomy with combined organ resection group (HR = 1.309, CI = 0.448-3.825, p = 0.622) did not show significant difference in disease-free survival from the mass excision only group, radical nephrectomy without combined organ resection group (HR = 0.279, CI = 0.078-0.991, p = 0.048) showed superior disease-free survival.

CONCLUSIONS

Radical nephrectomy of unilateral primary retroperitoneal liposarcoma near the kidney has a beneficial effect on disease-free survival.

Retroperitoneal Soft Tissue Sarcoma: Prognostic Factors and Therapeutic Approaches

Aims and Background

Retroperitoneal sarcomas are a rare group of malignant soft tissue tumors with a generally poor prognosis. The aim of the study was to assess clinical, pathological and treatment-related factors affecting prognosis in patients with retroperitoneal sarcomas.

Methods and Study Design

The hospital records of 73 patients who underwent surgical exploration at our unit for primary retroperitoneal sarcomas between 1984 and 2003 were reviewed. Factors influencing overall and disease-free survival were analyzed for all patients and for those who underwent complete surgical resection.

Results

The complete resectability rate was 69.8% (51/73). Operative mortality and morbidity rates were 2.7% and 21.9%, respectively. For patients who underwent complete resection, the 5-year survival rate was 58.3%, whereas it was 0% in cases of incomplete or no resection (P <0.001). Local recurrence rate was 37.2%. Incomplete gross surgical resection and microscopic infiltration of margins were the most important independent predictors of a poor prognosis.

Conclusions

The present study confirmed the importance of an aggressive surgical management for retroperitoneal sarcomas to offer these patients the best chance for long-term survival.

Hibernation of masses suspected to be remnant tumors after surgical resection of retroperitoneal liposarcoma is related to improved overall survival

BACKGROUND

Although complete surgical resection is considered the best treatment for retroperitoneal liposarcoma, it is related to a high local recurrence rate. This study analyzed patterns of recurrence of retroperitoneal liposarcoma.

METHODS

Records of patients who experienced recurrence after surgery for retroperitoneal liposarcoma from January 2000 to May 2017 were analyzed. Site, number, and characteristics of recurrent mass on computed tomography were serially collected. If a mass did not change size, it was considered a hibernating mass. Potential prognostic factors for overall survival were calculated using Kaplan-Meier survival log-rank tests.

RESULTS

A total of 74 patients, 28 within 6 months and 46 after 6 months, were detected as having a recurrence-suspected mass after surgery. Hibernation of a recurrence-suspected mass was found in 19 patients, 12 within 6 months and 7 after 6 months. While the presence of hibernation was not related to overall survival (P = 0.245), it was significantly related to improved survival in patients with a mass detected within 6 months (P = 0.022). Hibernation was not related to improved survival in patients with a mass detected after 6 months (P = 0.056).

CONCLUSIONS

Hibernation of a recurrence-suspected mass was related to improvement of overall survival in patients with a mass detected within 6 months. This specific patient group should be monitored with care to see if the size of the mass increases. When a mass seemed to be hibernating, a favorable prognosis could be expected.

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.

Multidisciplinary retroperitoneal and pelvic soft-tissue sarcoma case conferences: the added value that radiologists can provide

Clinical Vignette: A 50-year-old woman presents to the emergency department with increasing abdominal pain. Abdominal computed tomography imaging reveals an expanded inferior vena cava-filling defect that is suspicious for a retroperitoneal sarcoma, possibly a primary leiomyosarcoma of the inferior vena cava. The surgery team discusses the case with the radiologist, and all agree that there are multiple challenges with obtaining a tissue diagnosis and determining resectability. Thus, it is decided that this patient should be discussed at a multidisciplinary case conference. In the present article, we feature a case-based scenario focusing on the role of the radiologist in this type of multidisciplinary team.

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.

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.

Significant benefits in survival by the use of surgery combined with radiotherapy for retroperitoneal soft tissue sarcoma

BACKGROUND

To report the effect of intraoperative electron beam radiotherapy (IOERT) and external beam radiotherapy (EBRT) in addition to surgery as well as to evaluate the role of resectable local recurrence for long-term prognosis.

METHODS

In 53 patients who underwent surgery for retroperitoneal soft tissue sarcoma (RSTS) from 2001 to 2014 prognostic and epidemiologic factors were reviewed retrospectively to analyze their impact on survival and recurrence.

RESULTS

Twenty three patients (50%) had surgery plus radiotherapy, 23 (50%) had surgery only. Histology showed 73.9% liposarcoma, 15.2% leiomyosarcoma and 6.5% pleomorphic undifferentiated sarcoma respectively. Low grade sarcoma were observed in 52.2%, high grade sarcoma in 47.8%. The latter showed a trend towards a decreased 5-year survival rate (p = 0.125). Margin status was: R0: 60.9%, R1: 23.9%, R2: 15.2%; leading to significant changes in 5-year survival rate (R0: 77.6%; R1: 70.0%; R2: 42.9%; p = 0.03). Age younger than 55 years significantly improved 5-year survival rate (p = 0.039). Patients receiving resection of multiple sarcoma recurrence showed an almost identical improved 5-year survival rate compared to patients without recurrence (no recurrence: 100.0%; single recurrence: 35.0%; multiple recurrence: 91.7%; p = 0.001). Surgery plus radiotherapy led to significantly improved survival (p = 0.04).

CONCLUSIONS

There is a significant benefit in terms of 5-year survival after surgery plus some form of radiotherapy and a good prognosis for patients when the recurrence from RSTS was resected. Age older than 55 years and incomplete resection lowered 5-year survival rate significantly.

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.

Current classification, treatment options, and new perspectives in the management of adipocytic sarcomas

Sarcomas are a heterogeneous group of mesenchymal tumors arising from soft tissue or bone, with an uncertain etiology and difficult classification. Soft tissue sarcomas (STSs) account for around 1% of all adult cancers. Till date, more than 50 histologic subtypes have been identified. Adipocyte sarcoma or liposarcoma (LPS) is one of the most common STS subtypes, accounting for 15% of all sarcomas, with an incidence of 24% of all extremity STSs and 45% of all retroperitoneal STSs. The new World Health Organization classification system has divided LPS into four different subgroups: atypical lipomatous tumor/well-differentiated LPS, dedifferentiated LPS, myxoid LPS, and pleomorphic LPS. These lesions can develop at any location and exhibit different aggressive potentials reflecting their morphologic diversity and clinical behavior. Patients affected by LPS should be managed in specialized multidisciplinary cancer centers. Whereas surgical resection is the mainstay of treatment for localized disease, the benefits of adjuvant and neoadjuvant chemotherapy are still unclear. Systemic treatment, particularly chemotherapy, is still limited in metastatic disease. Despite the efforts toward a better understanding of the biology of LPS, the outcome of advanced and metastatic patients remains poor. The advent of targeted therapies may lead to an improvement of treatment options and clinical outcomes. A larger patient enrollment into translational and clinical studies will help increase the knowledge of the biological behavior of LPSs, test new drugs, and introduce new methodological studies, that is, on treatment response.