Optimizing surgical strategies for retroperitoneal liposarcoma: a comprehensive evaluation of standardized aggressive surgical policies

BACKGROUND

Retroperitoneal liposarcoma (RLPS) constitutes the majority of retroperitoneal sarcomas. While surgical resection remains the sole curative approach, determining the optimal surgical strategy for RLPS remains elusive. This study addresses the ongoing debate surrounding the optimal surgical strategy for RLPS.

METHODS

We recruited 77 patients with RLPS who underwent aggressive surgical policies. Patients were categorized into three surgical subtypes: suprapancreatic RLPS, pancreatic RLPS, and subpancreatic RLPS. Our standardized surgical strategy involved resecting macroscopically uninvolved adjacent organs according to surgical subtypes. We collected clinical, pathological and prognostic data for analyses.

RESULTS

The median follow-up was 45.5 months. Overall survival (OS) and recurrence-free survival (RFS) were significantly correlated with multifocal RLPS, pathological subtype, recurrent RLPS and histological grade (P for OS = 0.011, 0.004, 0.010, and < 0.001, P for RFS = 0.004, 0.001, < 0.001, and < 0.001, respectively). The 5-Year Estimate OS of well-differentiated liposarcoma (WDLPS), G1 RLPS, de novo RLPS and unifocal RLPS were 100%, 89.4%, 75.3% and 69.1%, respectively. The distant metastasis rate was 1.4%. The morbidity rates (≥ grade III) for suprapancreatic, pancreatic, and subpancreatic RLPS were 26.7%, 15.6%, and 13.3%, respectively. The perioperative mortality rate is 2.6%.

CONCLUSIONS

Standardized aggressive surgical policies demonstrated prognostic benefits for RLPS, particularly for G1 RLPS, WDLPS, unifocal RLPS, and de novo RLPS. This approach effectively balanced considerations of adequate exposure, surgical safety, and thorough removal of all fat tissue. G1 RLPS, WDLPS, unifocal RLPS, and de novo RLPS could be potential indications for aggressive surgical policies.

SPARC - A multi-disciplinary team program for retroperitoneal sarcoma: the Royal Prince Alfred Hospital and Chris O'Brien Lifehouse Collaboration

BACKGROUND

The Royal Prince Alfred Hospital (RPAH) and Chris O'Brien Lifehouse (COBLH) established a formal Sarcoma of the Pelvic and Abdominal Retroperitoneum Collaboration (SPARC) in November 2020. An established multidisciplinary team (MDT) with the aims to centralise patient referrals and treatment, establish database and research, coordinate surgical resections is critical in improving patient outcomes and quality of life.

METHODS

A prospective database was established in October 2021. Clinical, pathological and radiological data points were recorded for all patients since the inception of SPARC. Quality of Life questionnaires were included and follow-up planned regularly for 5 years.

RESULTS

From November 2020 to Feb 2024, 294 new referrals were discussed at the MDT meeting. Majority were from the metropolitan area (182) followed by regional NSW (87), interstate (20) and five internationals. 141 operations were performed during this period compared to 119 operations from 2010 to November 2020 in RPAH. The inception of the SPARC program has resulted in exponential growth in operations, improving from the previous rate of 15 cases annually to 35. Liposarcomas followed by leiomyosarcomas are the most common types of sarcomas resected. The majority were extended resections (81.6%) and 22% were pelvic exenterations. Overall R0 rate is 54.6%, R1 38.3% and R2 1.4% (131 (92.9%) had R0/R1 resections. Overall complication rate is 35.5% with one in-hospital mortality.

CONCLUSION

Success and expansion of a robust retroperitoneal sarcoma program requires a collaborative surgical approach, an MDT meeting, centralized referral process, and a research team in specialized tertiary institutions.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Gender Differences in Prognosis After Primary Resection for Retroperitoneal Liposarcoma

BACKGROUND

Current evidence regarding gender difference in retroperitoneal liposarcoma (RLPS) is scarce, so we sought to investigate whether gender may affect prognosis after primary resection of RLPS.

METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) database to identify RLPS patients from January 1973 to December 2015. Multivariate cox proportional hazard analysis was adopted to generate adjusted hazard ratio (AHR) and 95% confidence intervals (CIs) of survival outcomes.

RESULTS

In total, 2108 RLPS patients, including 971 women and 1137 men, were identified, with a median follow-up of 45.0 (17.0-92.0) months. The 5-year and 10-year overall survival rates were 50.5% and 31.5% for men and 60.4% and 42.5% for women. The 5-year and 10-year disease-specific survival rates for men and women were 71.5%, 57.3% and 76.3%, 62.1%, respectively. We found men were associated with an increased risk of all-cause mortality (AHR 1.3, 95% CI 1.0-1.6, P = .017) but not disease-specific mortality (AHR 1.2, 95% CI .9-1.6, P = .246). The subgroup analyses revealed that men were associated with an increased risk of all-cause mortality in patients with low-grade tumors (AHR 1.8, 95% CI 1.3-2.5) or patients who received non-radical resection (AHR 1.6, 95% CI 1.2-2.1). In the subgroup of low-grade tumors, men were also associated with an increased risk of disease-specific mortality (AHR 2.0, 95% CI 1.2-3.3).

CONCLUSION

Men may have worse survival after primary resection of RLPS compared with women, especially in patients with low-grade tumors or patients who received non-radical resection. Gender-based disparities may deserve more attention in patients with RLPS.

Progress in Retroperitoneal Sarcoma Management: Surgical and Radiotherapy Approaches

Surgical resection is the cornerstone of curative treatment for retroperitoneal sarcomas (RPS), aiming for complete excision, yet the complexity of RPS with its proximity to vital structures continues to lead to high local recurrence rates after surgery alone. Thus, the role of radiotherapy (RT) continues to be refined to improve local control, which remains an important goal to prevent RPS recurrence. The recently completed global randomized trial to evaluate the role of surgery with and without preoperative RT - STRASS1, did not demonstrate a significant overall benefit for neoadjuvant RT based on the pre-specified definition of abdominal recurrence-free survival, however, sensitivity analysis using a standard definition of local recurrence and analysis of outcomes by compliance to the RT protocol suggests histology-specific benefit in well- and some de-differentiated liposarcomas. Ultimately, multidisciplinary collaboration and personalized approaches that consider histological sarcoma types and patient-specific factors are imperative for optimizing the therapeutic strategy in the management of RPS.

Influence of nutritional status and body composition on postoperative events and outcome in patients treated for primary localized retroperitoneal sarcoma

BACKGROUND

Retroperitoneal sarcomas (RPS) are rare tumours of mesenchymal origin, commonly presented as a large tumour mass at time of diagnosis. We investigated the impact of body composition on outcome in patients operated on for primary localized RPS.

PATIENTS AND METHODS

We retrospectively analysed data for all patients operated on for primary RPS at our institution between 1999 and 2020. Preoperative skeletal muscle area (SMA), visceral and subcutaneous adipose tissue area (VAT and SAT) and muscle radiation attenuation (MRA) were calculated using computed tomography scans at the level of third lumbar vertebra. European Working Group on Sarcopenia in Older People (EWGSOP2) criteria were applied to define myopenia. Using maximum log-rank statistic method we determined the optimal cut-off values of body composition parameters. Myosteatosis was defined based on determined MRA cut-offs.

RESULTS

In total 58 patient were eligible for the study. With a median follow-up of 116 months, the estimated 5-year overall survival (OS) and local-recurrence free survival (LRFS) were 66.8% and 77.6%, respectively. Patients with myopenia had significantly lower 5-year OS compared to non-myopenic (p = 0.009). Skeletal muscle index and subcutaneous adipose tissue index predicted LRFS on univariate analysis (p = 0.052 and p = 0.039, respectively). In multivariate analysis high visceral-to-subcutaneous adipose tissue area ratio (VSR) independently predicted higher postoperative complication rate (89.2% vs. 10.8%, p = 0.008). Myosteatosis was associated with higher postoperative morbidity.

CONCLUSIONS

Myopenia affected survival, but not postoperative outcome in RPS. Visceral obesity, VSR (> 0.26) and myosteatosis were associated with higher postoperative morbidity. VSR was better prognostic factor than VAT in RPS.

Clinical characteristics and management of primary retroperitoneal sarcoma: A literature review

Retroperitoneal sarcoma (RPS) is a rare tumor classified into many histological types. It is also often detected only after it has grown to a considerable size and requires extensive resection of the surrounding organs, making it difficult to offer optimal patient-tailored management. Evidence supporting specific treatment modalities for RPS is insufficient, owing to its rarity. The Japanese clinical practice guidelines for RPS were published in December 2021, with the aim of accumulating existing evidence and indicating the optimal practice for RPS. These guidelines provide important clinical questions (CQs) concerning the diagnosis and treatment of RPS. This review, with a particular focus on primary RPS, attempts to introduce clinical problems in the diagnosis and treatment of RPS and to assess those problems along with the CQs in the guidelines. According to these guidelines, although chemotherapy and radiotherapy are expected to have therapeutic effects, the level of evidence to support these treatments is not very high at present. Accordingly, complete resection of the tumor is the first and only option for managing primary RPS. However, as with other tumors, the demand for multidisciplinary treatment for RPS is increasing. These guidelines will undoubtedly represent a milestone in clinical practice in relation to RPS in the future, and further evidence is expected to be accumulated based on the CQs that have been proposed.

A Rare Case of Dedifferentiated Liposarcoma with Osteosarcomatous Differentiation-Diagnostic and Therapeutic Challenges

INTRODUCTION

Liposarcomas are the most common of all sarcomas. A well-differentiated liposarcoma can transform into a dedifferentiated liposarcoma with myogenic, osteo- or chondrosarcomatous heterologous differentiation. Genomic amplification of MDM2 gene is then characteristic. Treatment usually involves surgical resection to radically remove the tumor. Other treatments such as chemotherapy and radiotherapy may also be used.

CASE REPORT

A 60-year-old patient was admitted to the hospital for surgical treatment of a left renal mass. The true location of the tumor was discovered only intraoperatively. The lesion was completely removed laparoscopically with preservation of the capsule. Genomic amplification of MDM2 gene was confirmed. One and a half years after surgery, despite the removal of the tumor without the surrounding margin of healthy tissue, the patient remains without recurrence.

CONCLUSION

Dedifferentiated liposarcoma with osteosarcomatous differentiation is a sporadic case and may occur in various locations of the retroperitoneal space, also mimicking a renal tumor. The laparoscopic technique is a safe surgical treatment for tumors of unclear origin. Removal of dedifferentiated liposarcoma with osteosarcomatous differentiation tumor with preservation of the lesion capsule without maintaining a margin of healthy tissue also allows for long-term cure. Precise immunohistochemical and molecular studies may have an impact on the effectiveness of further treatment and the prognosis of the patient. A patient after surgical treatment of liposarcoma requires constant outpatient follow-up for the reason of the high risk of local and distant recurrence.

Preoperative assessment of retroperitoneal Liposarcoma using volume-based 18F-FDG PET/CT: implications for surgical strategy and prognosis

PURPOSE

Retroperitoneal liposarcoma (RLPS) poses a challenging scenario for surgeons due to its unpredictable biological behavior. Surgery remains the primary curative option for RLPS; however, the need for additional information to guide surgical strategies persists. Volume-based 18F-FDG PET/CT may solve this issue.

METHODS

We analyzed data from 89 RLPS patients, measuring metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) and explored their associations with clinical, prognostic, and pathological factors.

RESULTS

MTV, TLG of multifocal and recurrent RLPS were significantly higher than unifocal and primary ones (P < 0.001, P < 0.001, P = 0.003 and P = 0.002, respectively). SUVmax correlated with FNCLCC histological grade, mitotic count and Ki-67 index (P for G1/G2 = 0.005, P for G2/G3 = 0.017, and P for G1/G3 = 0.001, P < 0.001 and P = 0.024, respectively). MTG, TLG and SUVmax of WDLPS were significantly lower than DDLPS and PLPS (P for MTV were 0.009 and 0.022, P for TLG were 0.028 and 0.048, and P for SUVmax were 0.027 and < 0.001, respectively). Multivariable Cox analysis showed that MTV > 457.65 (P = 0.025), pathological subtype (P = 0.049) and FNCLCC histological grade (P = 0.033) were related to overall survival (OS).

CONCLUSIONS

Our findings indicate that MTV is an independent prognostic factor for RLPS, while MTV, TLG, and SUVmax can preoperatively predict multifocal lesions, histological grade, and pathological subtype. Volume-based 18F-FDG PET/CT offers valuable information to aid in the decision-making process for RLPS surgical strategies.

Clinician survey of current global practice for sarcoma surveillance following resection of primary retroperitoneal, abdominal, and pelvic sarcoma

INTRODUCTION

- Postoperative surveillance following resection of primary retroperitoneal, abdominal, and pelvic sarcoma (RPS) is standard of care in international sarcoma centres and has rapidly evolved without an evidence base to become highly intensive and prolonged. This clinician survey aims to capture a global, contemporary snapshot of international guidelines used to inform sarcoma surveillance following resection of primary RPS.

MATERIALS AND METHODS

- Between July 2022 and March 2023, an online, anonymous, clinician survey to assess the current duration, imaging intervals and imaging modalities used for postoperative surveillance following resection of primary RPS was distributed among clinicians working at centres which are members of the TransAtlantic Australasian Retroperitoneal Working Group (TARPSWG).

RESULTS

- Responses were received from 58 different TARPSWG centres. The majority of centres use institutional guidelines to guide surveillance intensity (n = 43, 74%) and the surveillance imaging modality (n = 39, 67%) used. For surveillance intensity and imaging modality, institutional guidelines are partially or entirely based on international guidelines in 81% (n = 47) and 78% (n = 45) of centres, respectively. Commonly used imaging modalities are contrast-enhanced CT abdomen-pelvis (n = 51, 88%) for abdominal surveillance and non-contrast enhanced CT (n = 25, 43%) for chest surveillance. Imaging intervals, timing of de-escalation of imaging frequency and total duration of surveillance for low-grade and high-grade RPS are reported.

CONCLUSION

- This global survey among TARPSWG members demonstrates the heterogeneity in sarcoma surveillance strategies worldwide and emphasises the need for a randomised controlled trial to provide an evidence base for the optimal surveillance schedule following primary resection of RPS.

Nomogram development and external validation for predicting overall survival and cancer-specific survival in patients with primary retroperitoneal sarcoma: a retrospective cohort study

BACKGROUND

Primary retroperitoneal sarcoma (RPS) comprises over 70 histologic subtypes, yet there are limited studies that have developed prognostic nomograms for RPS patients to predict overall survival (OS) and cancer-specific survival (CSS). The objective of this study was to construct prognostic nomograms for predicting OS and CSS in RPS patients.

METHODS

We identified a total of 1166 RPS patients from the Surveillance, Epidemiology and End Results (SEER) database, and an additional 261 cases were collected from a tertiary cancer center. The study incorporated various clinicopathological and epidemiologic features as variables, and prediction windows for overall survival (OS) and cancer-specific survival (CSS) were set at 3, 5, and 7 years. Multivariable Cox models were utilized to develop the nomograms, and variable selection was performed using a backward procedure based on the Akaike Information Criterion. To evaluate the performance of the nomograms in terms of calibration and discrimination, we used calibration plots, coherence index, and area under the curve.

FINDINGS

The study included 818 patients in the development cohort, 348 patients in the internal validation cohort, and 261 patients in the external validation cohort. The backward procedure selected the following variables: age, French Federation of Cancer Centers Sarcoma Group (FNCLCC) grade, pre-/postoperative chemotherapy, tumor size, primary site surgery, and tumor multifocality. The validation results demonstrated that the nomograms had good calibration and discrimination, with C-indices of 0.76 for OS and 0.81 for CSS. Calibration plots also showed good consistency between the predicted and actual survival rates. Furthermore, the areas under the time-dependent receiver operating characteristic curves for the 3-, 5-, and 7-year OS (0.84, 0.82, and 0.78, respectively) and CSS (0.88, 0.88, and 0.85, respectively) confirmed the accuracy of the nomograms.

INTERPRETATION

Our study developed accurate nomograms to predict OS and CSS in patients with RPS. These nomograms have important clinical implications and can assist healthcare providers in making informed decisions regarding patient care and treatment options. They may also aid in patient counseling and stratification in clinical trials.

Spindle Cell Renal Neoplasms: A Pathological Case Report on Primary Renal Leiomyosarcoma and Sarcomatoid Renal Cell Carcinoma

Renal oncopathology in adults, as a field of pathology, is dominated by a single entity - clear cell renal cell carcinoma (RCC) with other entries, such as urothelial carcinoma of the renal pelvis, angiosarcoma, and others being extremely rare. Herein, we report two histopathological cases with differential diagnoses of spindle cell renal neoplasms. The first patient, a 42-year-old male, presented with new-onset right-sided abdominal flank pain, and imaging showed a 12 cm renal tumor. Histopathology showed a spindle cell neoplasm, with significant mitotic activity and giant cell, with immunohistochemistry being positive for caldesmon and vimentin, focally for smooth muscle actin (SMA). No reaction was noted for pan-cytokeratin (CK AE1/AE3), epithelial membrane antigen (EMA), cytokeratin (CK) 7, cluster of differentiation (CD) 117, soluble 100 protein (S100), human melanoma black (HMB) 45, Melan A, CD10, and desmin. Due to peculiar histomorphology and the immunophenotype, the tumor was interpreted as primary renal leiomyosarcoma. Due to continuous outpatient consultations, treatment initiation was delayed, and three months later, the patient had already developed an 87 mm local recurrence and liver metastasis. The second patient, a 53-year-old male, presented to our institution for consultation of an already excised renal tumor, diagnosed as an incidental finding on a prophylactic abdominal ultrasound. The tumor presented for consultation histologically grew as intertwining bundles of spindle cells with polymorphic hyperchromic nuclei with prominent nucleoli and had extensive areas with necrosis. Immunohistochemically, the tumor diffusely expressed CK AE1/AE3 and caldesmon and had a patchy reaction for EMA and CD10. The SMA, desmin, CD117, and CK7 reactions were negative; hence, the tumor was interpreted as a spindle cell variety (sub-type) of clear RCC.

Six Surgical Stages in the Resection of Primary Right Retroperitoneal Liposarcoma: A Standardized Comprehensive Approach

BACKGROUND

Surgery is the treatment mainstay in retroperitoneal sarcoma (RPS), a frontline comprehensive approach based on tumor removal en bloc with adherent viscera is mandatory especially for liposarcoma, where the normal retroperitoneal fat is undistinguishable from the well-differentiated tumor component.1-5 In this video, a reproducible and standardized six-stage approach to a primary right retroperitoneal liposarcoma is presented.

PATIENT AND METHODS

A 23-cm right retroperitoneal, well-differentiated liposarcoma was diagnosed in a 68-year-old female patient in December 2021. The tumor involved the right kidney and adrenal gland; displacing anteriorly the right colon, the duodenum, and the pancreatic head; and invading part of the ipsilateral psoas muscle. After the publication of the STRASS trial and STREXIT results,6,7 neoadjuvant radiotherapy was delivered to a total dose of 50.4 Gy in 28 fractions with stable disease. Virtual 3D reconstruction of regional anatomy by Visible Patient was performed preoperatively.

RESULTS

The patient underwent right retroperitoneal mass resection en bloc with ipsilateral kidney and adrenal gland, colon, psoas muscle, and portion of ipsilateral diaphragm. Of note, the resection of the psoas muscle was performed to obtain a safe posterior margin and accomplish a better clearance of fat of the posterior abdominal wall. This can be limited to the psoas fascia whenever the tumor is not adherent to it. A six-stage approach was performed, as described in the supplementary video file.

CONCLUSIONS

RPS resection is complex and requires a broad range of surgical expertise. A staged approach that can be followed in virtually all cases is highly recommended to achieve an optimal tumor resection.

Giant paratesticular dedifferentiated liposarcoma with intraabdominal extension: a case report

Giant paratesticular liposarcoma is a rare presentation of paratesticular tumor. We present a case of the largest paratesticular liposarcoma described to date with a weight of 4,100 g and measuring 460 × 210 × 130 mm. It was initially mistaken as an inguinoscrotal hernia until a contrast-enhanced computed tomography (CECT) scan of the abdomen and pelvis revealed a huge left paratesticular tumor extending from the scrotum to the mid-abdomen. The challenge was to achieve a tumor-free margin orchidectomy due to the poor fat plane of the tumor to the external iliac artery, psoas muscle, descending colon, and anterior abdominal wall. The surgery was started with laparoscopic dissection for the intraabdominal part of tumor from the vital structure, then followed by inguinal radical orchidectomy and inguinal mesh repair. Postoperative histopathological report revealed a paratesticular dedifferentiated liposarcoma with rhabdomyosarcomatous differentiation with clear margin. The patient had good recovery post operation.

Primary Bladder Sarcoma: A multi-institutional experience from the Rare Cancer Network

PURPOSE OR OBJECTIVE

Primary sarcoma of the urinary bladder (SUB) is a rare but aggressive form of bladder cancer (BCa). Available evidence on SUB is limited to case reports and small series. The aim of the present multi-institutional study was to assess the clinical features, treatments, and outcomes of patients with SUB.

MATERIALS AND METHODS

Using a standardized database, 7 institutions retrospectively collected the demographics, risk factors, clinical presentation, treatment modalities and follow-up data on patients with SUB between January 1994 and September 2021. The main inclusion criteria included BCa with soft tissue tumor histology and sarcomatoid differentiation.

RESULTS

Fifty-three patients (38 men and 15 women) were identified. Median follow-up was 18 months (range 1-263 months). Median age at presentation was 69 years (range 16-89 years). Twenty-six percent of patients had a prior history of pelvic radiotherapy (RT), and 37% were previous smokers. The main presenting symptoms at diagnosis were hematuria (52%), pelvic pain (27%), and both hematuria and pelvic pain (10%). American Joint Committee on Cancer (AJCC) 8 th edition stage II, III and IV at diagnosis were 21%, 63% and 16%, respectively. Treatment modalities included surgery alone (45%), surgery plus neo- or adjuvant-chemotherapy (17%), surgery plus neo- or adjuvant-RT (11%), RT with concurrent chemotherapy (4%), neo-adjuvant chemotherapy plus surgery plus adjuvant RT (2%) and palliative treatment (21%). Rates of local and distant recurrences were 49% and 37%, respectively. Five-year overall survival and progression-free survival (PFS) were 66.5% and 37.6%, respectively. No statistically significant differences in PFS between the treatment modalities were observed.

CONCLUSIONS

Primary SUB is a heterogeneous disease group, commonly presenting at advanced stages and exhibiting aggressive disease evolution. In contrast to urothelial carcinoma, the primary pattern of recurrence of SUB is local, suggesting the need for multimodal approaches. Continuous international collaborative efforts seem warranted to provide guidance on how to best tailor treatments based on SUB-specific indices.

Preoperative Radiotherapy in Patients With Primary Retroperitoneal Sarcoma: EORTC-62092 Trial (STRASS) Versus Off-trial (STREXIT) Results

OBJECTIVE

The aim of the present study was to compare the effect of radiotherapy (RT) on abdominal recurrence-free survival (ARFS) in patients with primary retroperitoneal sarcoma treated in the EORTC-STBSG-62092 (STRASS) phase 3 randomized controlled trial (STRASS cohort) and off-trial (STREXIT cohort) and to pool STRASS and STREXIT data to test the hypothesis that RT improves ARFS in patients with liposarcoma.

BACKGROUND

The STRASS trial did not show any difference in ARFS between patients treated with preoperative radiotherapy+surgery (RT+S) versus surgery alone (S).

METHODS

All consecutive adult patients not enrolled in STRASS and underwent curative-intent surgery for a primary retroperitoneal sarcoma with or without preoperative RT between 2012 and 2017 (STRASS recruiting period) among ten STRASS-recruiting centres formed the STREXIT cohort. The effect of RT in STREXIT was explored with a propensity score (PS)-matching analysis. Primary endpoint was ARFS defined as macroscopically incomplete resection or abdominal recurrence or death of any cause, whichever occurred first.

RESULTS

STRASS included 266 patients, STREXIT included 831 patients (727 after excluding patients who received preoperative chemotherapy, 202 after 1:1 PS-matching). The effect of RT on ARFS in STRASS and 1:1 PS-matched STREXIT cohorts, overall and in patients with liposarcoma, was similar. In the pooled cohort analysis, RT administration was associated with better ARFS in patients with liposarcoma [N=321, hazard ratio (HR), 0.61; 95% confidence interval (CI), 0.42-0.89]. In particular, patients with well-differentiated liposarcoma and G1-2 dedifferentiated liposarcoma (G1-2 DDLPS, n=266) treated with RT+S had better ARFS (HR, 0.63; 95% CI, 0.40-0.97) while patients with G3 DDLPS and leiomyosarcoma had not. At the current follow-up, there was no association between RT and overall survival or distant metastases-free survival.

CONCLUSIONS

In this study, preoperative RT was associated with better ARFS in patients with primary well-differentiated liposarcoma and G1-2 DDLPS.

Epidemiology, pathological characteristics and survival of retroperitoneal soft‑tissue sarcomas compared with non‑retroperitoneal soft tissue sarcomas

Retroperitoneal soft-tissue sarcomas (RPS) are rare forms of mesenchymal tumors that account for ~0.15% of all malignancies. The purpose of the present study was to determine the differences between RPS and non-RPS anatomopathological and clinical features and to analyze whether the hazard ratio for short-term mortality differs between patients with RPS and non-RPS, after adjusting for differences in baseline anatomopathological and clinical features. The Veneto Cancer Registry, a high-resolution population-based dataset spanning the regional population, was used as a data source for the analysis. The current analysis focuses on all incident cases of soft-tissue sarcoma recorded by the Registry from January 1, 2017 to December 31, 2018. A bivariate analysis was carried out to compare demographic and clinical characteristics in RPS and non-RPS. Short-term mortality risk was analyzed by primary tumor site. The significance of variations in survival by site group was determined using Kaplan-Meier curves and the Log-rank test. Finally, Cox regression was used to assess the hazard ratio for survival by sarcoma group. RPS accounted for 22.8% of the total sample (92 out of 404 cases). The mean age at diagnosis was 67.6 years for RPS vs. 63.4 for non-RPS; 41.3% of RPS were >150 mm vs. 5.5% for non-RPS. Stages III and IV were more prevalent in RPS (53.2 vs. 35.6%), despite the fact that, in both groups, advanced stages are the most common onset at diagnosis. Regarding surgical margins, the present study showed that R0 is the most prevalent in non-RPS (48.7%), while R1-R2 is the most frequent in patients with RPS (39.1%). The 3-year mortality rate for retroperitoneum was 42.9 vs. 25.7%. Comparing RPS and non-RPS, the multivariable Cox model showed a hazard ratio of 1.58 after adjusting for all other prognostic factors. RPS clinical and anatomopathological characteristics differ from those of non-RPS. Overall, despite adjusting for other prognostic factors, the retroperitoneum site was an independent prognostic factor associated with a worse overall survival in sarcoma patients compared with other sites.

Sarcoma Research with Cancer Registry Data: Data and Peculiarities of Germany in the Light of Other Countries

INTRODUCTION

Sarcomas are documented in population-based and in clinic-associated databases. This study evaluated the status quo regarding the potential and obstacles of cancer registry-based research on sarcomas exemplified by Germany in comparison to similar databases in the US and Europe. Completeness and quality of data are discussed based on statistical analyses of a pooled data set established for the German Cancer Congress 2020.

METHODS

We analyzed data derived from 16 German institutions (federal state cancer registries and some facility-based registries). Malignant sarcomas in adults diagnosed between 2000 and 2018 with information on histology were grouped according to the WHO classification of soft tissue and bone tumors. Descriptive analyses of the study population regarding the distribution of age, sex, histology, localization of primary tumors, and metastases were performed. Survival for the ten most frequent histological groups and UICC stages was evaluated according to Kaplan-Meier and Cox regression. Time interval between surgery and subsequent radiation was calculated.

RESULTS

The initial data set contained 35,091 sarcomas. After several steps of data cleaning, 28,311 patients with known sex and unambiguous assignment to a histological subgroup remained (13,682 women and 14,629 men). Between 40 and 54 years, women were more likely to develop sarcomas, whereas in the older age groups more men were affected. Gastrointestinal stromal tumors, fibroblastic, and myofibroblastic tumors, smooth muscle tumors (mostly non-uterine leiomyosarcomas), and adipocytic tumors represented 48% of all sarcomas. Preferential sites for fibrosarcomas were the limbs, the trunk, and the head and neck region. The liposarcoma occurred most frequently on the trunk and limbs. Distant primary metastases were mostly located in the lung (43%), followed by the liver (14%), and bones (13%). Vascular and smooth muscle tumors showed the worst survival prognosis (5-year survival: approx. 15%, median survival approx. 8-16 months), whereas in low stages, the probability of survival of many sarcoma patients was beyond 5 years. Adjuvant radiotherapy was applied within 90 days in 71% of patients (n = 2,534).

CONCLUSION

Our results correspond to the data from the literature. However, a lack of data quality and completeness hampers further meaningful analyses, especially nonspecific or missing information about morphology and stage. Compared to some other countries, a comprehensive database is presently missing in Germany. However, currently, there are important efforts and legislative initiatives to create a comprehensive database on a national level within the near future.

High grade leiomyosarcoma of the transverse colon with positive lymph node metastasis: to treat or not to treat with adjuvant radiation therapy?

Intra-abdominal leiomyosarcomas (LMSs) are aggressive malignant tumours arising from smooth muscle cells. These neoplasms are extremely rare and account for 10%-20% of primary soft tissue sarcomas and approximately 0.1% of all colorectal malignancies. Intra-abdominal LMS has a very poor prognosis with an estimated 5-year survival rate between 20% and 50% and the size of the tumour being the main determinant of prognosis. Treatment is further complicated by different anatomic variants with differing clinical behaviours impacting prognosis. Newer techniques in radiation treatment such as intensity-modulated, intraoperative electron and proton beam radiotherapies allow for cases with high probability of local recurrence or likelihood of residual microscopic disease after surgical resection to be treated with precise radiation doses to the targeted tumour volume. We present a case of high grade LMS of the distal transverse colon with positive lymph node metastasis treated by surgical excision followed by adjuvant radiotherapy and discuss the current role of radiotherapy.

Data Dissemination of the Role of Neoadjuvant Radiation in Retroperitoneal Sarcoma: A CTOS and CSSO Survey

Consensus guidelines call for complete resection of retroperitoneal sarcoma with consideration of neoadjuvant radiation for curative-intent treatment. The 15-month delay from the initial presentation of an abstract to the final publication of the STRASS trial results assessing the impact of neoadjuvant radiation led to a dilemma of how patients should be managed in the interim. This study aims to (1) understand perspectives regarding neoadjuvant radiation for RPS during this period; and (2) assess the process of integrating data into practice. A survey was distributed to international organizations including all specialties treating RPS. Eighty clinicians responded, including surgical (60.5%), radiation (21.0%) and medical oncologists (18.5%). Low kappa correlation coefficients on a series of clinical scenarios querying individual recommendations before and after initial presentation as an abstract indicate considerable change. Over 62% of respondents identified a practice change; however, most also noted discomfort in adopting changes without a manuscript available. Of the 45 respondents indicating discomfort with practice changes without a full manuscript, 28 (62%) indicated that their practice changed in response to the abstract. There was substantial variability in recommendations for neoadjuvant radiation between the presentation of the abstract and the publication of trial results. The difference in the proportion of clinicians describing comfort with changing practice based on the presentation of the abstract versus those that had done so shows that indications for proper integration of data into practice are not clear. Endeavors to resolve this ambiguity and expedite availability of practice-changing data are warranted.

Effect of pre-operative radiation therapy on surgical outcome in retroperitoneal sarcoma

Background

A high rate of locoregional recurrence is one of the major difficulties in successful treatment of retroperitoneal sarcoma (RPS). Although pre-operative radiation therapy (RT) is considered a potential way to improve local recurrence, concerns about the associated treatment toxicity and risk of peri-operative complications need to be addressed. Hence, this study investigates the safety of pre-operative RT (preRTx) for RPS.

Methods

A cohort of 198 patients with RPS who had undergone both surgery and RT was analyzed for peri-operative complications. They were divided into three groups according to the RT scheme: (1) preRTx group, (2) post-operative RT without tissue expander, and (3) post-operative RT with tissue expander.

Results

The preRTx was overall well tolerated and did not affect the R2 resection rate, operative time, and severe post-operative complications. However, the preRTx group was associated with higher incidence of post-operative transfusion and admission to intensive care unit (p = 0.013 and p = 0.036, respectively), where preRTx was an independent risk factor only for the post-operative transfusion (p = 0.009) in multivariate analysis. The median radiation dose was the highest in preRTx group, although no significant difference was demonstrated in overall survival and local recurrence rate.

Conclusion

This study suggests that the preRTx does not add significant post-operative morbidity to the patients with RPS. In addition, radiation dose elevation is achievable with the pre-operative RT. However, a meticulous intra-operative bleeding control is recommended in those patients, and further high-quality trials are warranted to evaluate the long-term oncological outcomes.

New developments in the pathology and molecular biology of retroperitoneal sarcomas

Retroperitoneal sarcomas (RPS) refer to a heterogeneous group of malignancies of mesenchymal origin developing from retroperitoneal tissues and vessels. The most frequent RPS are well differentiated/dedifferentiated liposarcomas and leiomyosarcomas, but other rare histological subtypes can be observed. Over the last decade, significant advances have been made in the pathological and molecular characterization of sarcomas. These advances have led to major changes in their diagnostic management as well as in the development of new therapeutic strategies based on tumor biology and microenvironment. This review describes the current knowledge and recent findings in the pathology and molecular biology of the most frequent RPS subtypes.

Histology-tailored multidisciplinary management of primary retroperitoneal sarcomas

Until recently, the recommendation for primary retroperitoneal sarcomas (RPS) was to perform a complete en-bloc gross excision, (neo) adjuvant treatments being options which were not validated by randomized studies, with a large discrepancy of use between centers. The heterogeneity of RPS, with their different biological behaviour, renders a homogenous therapeutic and surgical approach probably inappropriate. Recent studies, both surgical and dedicated to adjuvant treatments, allow refining these recommendations. This review summarizes recent advances and directions.

How to treat liposarcomas located in retroperitoneum

Almost half of retroperitoneal (RP) sarcomas are liposarcomas (LPS). The large majority of RP LPS are either well-differentiated LPS (WDLPS) or dedifferentiated LPS (DDLPS), these latter further classified according to grading in G2 and G3 DDLPS. Surgery is the only potentially curative treatment to achieve local control and possibly cure in primary localized disease. Over the last decade, a better delineation of the different histology-specific patterns of failure and the development of nomograms predictors of outcome has led to a better management of these rare tumors, with a special focus on non-surgical treatments. Available evidences - although far from exhaustive - show that radiation therapy might have a role, if any, as neoadjuvant treatment in locally aggressive histologies (i.e. WDLPS and G2 DDLPS), while it does not seem beneficial for histologies with a higher metastatic risk (i.e. G3 DDLPS and leiomyosarcoma). Neoadjuvant chemotherapy, instead, can be considered to reduce the risk of distant metastasis while waiting for the results of an ongoing RCT (STRASS-2) evaluating its effect in these tumors. However, given the rarity of these diseases and the subsequent lack of strong evidences to guide treatment, outcome improvement in these patients remains a challenge. Patients' referral to a sarcoma center where a dedicated specialized multidisciplinary team tailor optimal treatment on a case-by-case basis is crucial to ensure these patients the best outcome. Refining available nomograms - e.g including molecular variables - and identifying predictors of response/toxicity to chemotherapy and immunotherapy might be significantly helpful in tailoring treatments to the patient's characteristics. Also, new systemic agents are eagerly awaited for improving the management further.

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.

Experiences of patients and their relatives of postoperative radiological surveillance and surveillance intensity following primary resection of a soft tissue sarcoma and its impact on their quality of life: a systematic review protocol

INTRODUCTION

Postoperative radiological surveillance following primary resection of a soft tissue sarcoma (sarcoma of the retroperitoneum, abdomen, pelvis, trunk or extremities) is standard of care in all international high-volume sarcoma centres in the world. The intensity of postoperative surveillance imaging is highly varied and knowledge of the impact of surveillance and surveillance intensity on patients' quality of life is limited. The aim of this systematic review is to summarise the experiences of patients and their relatives/caregivers of postoperative radiological surveillance following resection of a primary soft tissue sarcoma and its impact on their quality of life.

METHODS AND ANALYSIS

We will systematically search MEDLINE, EMBASE, PsycINFO, CINAHL Plus and Epistemonikos. Hand searching of reference lists of included studies will be conducted. Further searches will be performed via Google Scholar, to reveal further studies within unpublished 'grey' literature. Two reviewers will independently screen the titles and abstracts following the eligibility criteria. After retrieval of the full text of the selected studies, the methodological quality will be appraised using the Joanna Briggs Institute Critical Appraisal Checklist for Qualitative Research and the Center for Evidence-Based Management checklist for Critical Appraisal of a Cross-Sectional Study. Data on the study population, relevant themes and conclusions will be extracted from the selected papers, and a narrative synthesis will be conducted.

ETHICS AND DISSEMINATION

The systematic review does not require ethics approval. The findings of the proposed work will be published in a peer-reviewed journal and disseminated widely to patients, clinicians and allied health professionals through the Sarcoma UK website, the Sarcoma Patient Advocacy Global Network and the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group. In addition, the outcomes of this research will be presented at national and international conferences.

PROSPERO REGISTRATION NUMBER

CRD42022375118.

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.

Neoadjuvant radiotherapy for resectable retroperitoneal sarcoma: a meta-analysis

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Issues of diagnostic search of soft tissue sarcoma

Relevance. Soft tissue sarcoma is a heterogeneous group of relatively rare types of tumors, which demonstrates a huge variety of anatomical localization and histopathological characteristics. The rarity of soft tissue sarcomas combined with a variety of subtypes, forms of growth, progression and frequency of relapses makes it difficult to study them, make a correct diagnosis and early referral of patients for specialized care.

The purpose of study. To analyze the problem of differential diagnosis of malignant and benign soft tissue neoplasms.

Materials and methods. In the course of the work, current literary sources of domestic and foreign authors on a given topic were analyzed.

Results. Since it is absolutely impossible to determine the clinical features of the presented sarcoma, soft tissue tumors showing any of the following signs are considered malignant until the opposite is proven: increasing in size, >5 cm, deeply located and/or painful. The greater the number of these clinical signs present, the higher the risk that the soft tissue tumor will turn out to be malignant; at the same time, an increase in size is the best individual indicator. It is worth noting that the absence of concomitant constitutional symptoms, such as fever, chills, night sweats or unintentional weight loss, should not reduce the doctor's suspicion of malignancy.

Conclusion. In order to avoid erroneous diagnoses, a standardized diagnostic approach should be followed, starting from the moment of collecting the patient's medical history, clinical examination and ending with the use of appropriate imaging methods and biopsy.

Issues of diagnostic search of soft tissue sarcoma

Relevance. Soft tissue sarcoma is a heterogeneous group of relatively rare types of tumors, which demonstrates a huge variety of anatomical localization and histopathological characteristics. The rarity of soft tissue sarcomas combined with a variety of subtypes, forms of growth, progression and frequency of relapses makes it difficult to study them, make a correct diagnosis and early referral of patients for specialized care.

The purpose of study. To analyze the problem of differential diagnosis of malignant and benign soft tissue neoplasms.

Materials and methods. In the course of the work, current literary sources of domestic and foreign authors on a given topic were analyzed.

Results. Since it is absolutely impossible to determine the clinical features of the presented sarcoma, soft tissue tumors showing any of the following signs are considered malignant until the opposite is proven: increasing in size, >5 cm, deeply located and/or painful. The greater the number of these clinical signs present, the higher the risk that the soft tissue tumor will turn out to be malignant; at the same time, an increase in size is the best individual indicator. It is worth noting that the absence of concomitant constitutional symptoms, such as fever, chills, night sweats or unintentional weight loss, should not reduce the doctor's suspicion of malignancy.

Conclusion. In order to avoid erroneous diagnoses, a standardized diagnostic approach should be followed, starting from the moment of collecting the patient's medical history, clinical examination and ending with the use of appropriate imaging methods and biopsy.

Analysis of potential risk factors in the survival of patients with primary retroperitoneal liposarcoma

INTRODUCTION

The present work is an observational study of a series of variables regarding overall survival and disease-free survival in patients diagnosed with primary liposarcoma.

METHODS

The study is prospective with retrolective data collection that includes all patients with primary liposarcoma referred to Hospital Son Espases University Hospital, Palma de Mallorca, Spain from January 1990 to December 2019.

RESULTS

The study includes 50 patients and the compartment surgery was performed in 18 patients (36%) of cases. The mean overall survival of the sample was 15.57 years (95% CI: 12.02-19.12) and the mean disease-free survival was 6.70 years (95% CI: 4.50-8.86).

CONCLUSION

Compartment surgery has not shown benefits in terms of overall survival and disease-free survival. The ASA classification (≥3) predicts a poor prognosis in both overall survival and disease-free survival. Resection with free margins, described on the pathological results and defined in this work as R0, show better disease-free survival.

Multidimensional characteristics, prognostic role, and preoperative prediction of peritoneal sarcomatosis in retroperitoneal sarcoma

Background

Peritoneal sarcomatosis (PS) could occur in patients with retroperitoneal sarcomas (RPS). This study aimed to expand the understanding of PS on its characteristics and prognostic role, and develop a nomogram to predict its occurrence preoperatively.

Methods

Data of 211 consecutive patients with RPS who underwent surgical treatment between 2011 and 2019 was retrospectively reviewed. First, the clinicopathological characteristics of PS were summarized and analyzed. Second, the disease-specific survival (DSS) and recurrence-free survival (RFS) of patients were analyzed to evaluate the prognostic role of PS. Third, preoperative imaging, nearly the only way to detect PS preoperatively, was combined with other screened risk factors to develop a nomogram. The performance of the nomogram was assessed.

Results

Among the 211 patients, 49 (23.2%) patients had PS with an incidence of 13.0% in the primary patients and 35.4% in the recurrent patients. The highest incidence of PS occurred in dedifferentiated liposarcoma (25.3%) and undifferentiated pleomorphic sarcoma (25.0%). The diagnostic sensitivity of the preoperative imaging was 71.4% and its specificity was 92.6%. The maximum standardized uptake value (SUVmax) was elevated in patients with PS (P&lt;0.001). IHC staining for liposarcoma revealed that the expression of VEGFR-2 was significantly higher in the PS group than that in the non-PS group (P = 0.008). Survival analysis (n =196) showed significantly worse DSS in the PS group than in non-PS group (median: 16.0 months vs. not reached, P &lt; 0.001). In addition, PS was proven as one of the most significant prognostic predictors of both DSS and RFS by random survival forest algorithm. A nomogram to predict PS status was developed based on preoperative imaging combined with four risk factors including the presentation status (primary vs. recurrent), ascites, SUVmax, and tumor size. The nomogram significantly improved the diagnostic sensitivity compared to preoperative imaging alone (44/49, 89.8% vs. 35/49, 71.4%). The C-statistics of the nomogram was 0.932, and similar C-statistics (0.886) was achieved at internal cross-validation.

Conclusion

PS is a significant prognostic indicator for RPS, and it occurs more often in recurrent RPS and in RPS with higher malignant tendency. The proposed nomogram is effective to predict PS preoperatively.

Intra and extra pelvic multidisciplinary surgical approach of retroperitoneal sarcoma: Case series report

BACKGROUND

Retroperitoneal sarcoma (RPS) is a rare malignancy arising from mesenchymal cells that most commonly presents as an abdominal mass and is associated with poor prognosis. Although several studies have assessed the survival benefits of wide excision, few have reported detailed methods for achieving wide excision in patients with RPS.

AIM

To describe our experience with multidisciplinary surgical resection of RPS using intra- and extra-pelvic approaches.

METHODS

Multidisciplinary surgery is an anatomical approach that combines intra- and extra-peritoneal access within the same surgery to achieve complete RPS removal. This retrospective review of the records of patients who underwent multidisciplinary surgery for RPS analyzed surgical and survival outcomes.

RESULTS

Eight patients underwent 10 intra- and extra-pelvic surgical resections, and their median mass size was 12.75 cm (range, 6-45.5 cm). Using an intrapelvic approach, laparoscopy-assisted surgery was performed in four cases and laparotomy surgery in six. Using an extrapelvic approach, ilioinguinal and posterior approaches were used in four cases each, and the prone position and midline skin incision were shared in one. All patients’ RPS masses were removed completely, and four achieved R0 resection through intra- and extra-pelvic surgery. The median estimated blood loss was 2000 mL (range, 300-20000 mL) and the median hospitalization was 12.6 d (range, 9-69 d). Reoperation was needed in two patients (one for wound necrosis and the other for bowel perforation and wound necrosis). The median overall survival rate and median progression-free survival were 64.6 and 13.7 mo, respectively.

CONCLUSION

RPS is therapeutically challenging because of its location and high risk of recurrence. Therefore, intra- and extra-pelvic surgical approaches can improve the macroscopic security of the surgical margin.

Surgical Principles of Primary Retroperitoneal Sarcoma in the Era of Personalized Treatment: A Review of the Frontline Extended Surgery

Simple Summary

Surgery is the only curative treatment for localized disease in retroperitoneal sarcoma (RPS). Frontline extended surgery, or compartmental surgery, is a recent surgical strategy consisting of resecting the tumor together with adjacent organs, with the aim of minimizing marginality. This review provides a practical step by step description of this standardized procedure, tailored to histologic behavior, tumor localization, and patient condition.

Abstract

Surgery is the key treatment in retroperitoneal sarcoma (RPS), as completeness of resection is the most important prognostic factor related to treatment. Compartmental surgery/frontline extended approach is based on soft-tissue sarcoma surgical principles, and involves resecting adjacent viscera to achieve a wide negative margin. This extended approach is associated with improved local control and survival. This surgery must be tailored to tumor histology, tumor localization, and patient performance status. We herein present a review of compartmental surgery principles, covering the oncological and technical basis, and describing the tailored approach to each tumor subtype and localization in the retroperitoneum.

A systematic review of margin status in retroperitoneal liposarcomas: Does the R0 margin matter?

Retroperitoneal liposarcomas (RPLPSs) are a rare tumor group for which current guidelines recommend aggressive en bloc resection to attain microscopically negative (R0) margins. To ensure R0 margins, resection of adherent or adjacent organs is often required. However, it is still unclear if R0 margins confer any additional benefit to patients over a grossly negative but microscopically positive (R1) margin. We performed a systematic search of PubMed and Embase databases for studies including patients receiving R0 or R1 resection for RPLPS. Nine retrospective cohort studies, one prospective cohort study, and 49 case reports/case series were included. A total of 552 patients with RPLPS were evaluated: 346 underwent R0 resection and 206 underwent R1 resection. In the R0 group, 5-year overall survival (OS) ranged from 58.3% to 85.7%; local recurrence (LR) ranged from 45.5% to 52.3%. In the R1 group, 5-year OS ranged from 35% to 55.3%; LR ranged from 66.7% to 91.7%. Among cohort studies, OS, disease-free survival (DFS), LR rate, and LR-free survival (LRFS) were significantly associated with R0 resections. Assessment of case series and reports suggested that the R0 margin led to a slightly higher morbidity than that of R1. In conclusion, this review found the R0 margin to be associated with reductions in LR rates and improved OS when compared with the R1 margins, though accompanied by slight increases in morbidity. The roles of tumor histotype and perioperative chemotherapy or radiotherapy were not well-elucidated in this review.

Retroperitoneal Sarcomas: Histology Is Everything

Retroperitoneal sarcomas (RPS) are a rare subset of soft tissue sarcoma that are composed of only a few histologic subtypes, each with a distinct tumor biology, clinical presentation, preferred treatment strategy, recurrence risk, and surveillance plan. In the modern era of precision medicine, our understanding of the implications of subtype tumor biology and anatomic location has led to a more nuanced, histology-specific approach to therapy, including surgery, neoadjuvant radiation therapy, and/or chemotherapy. This article provides a summary of recent updates to the management of RPS.

Survival outcomes of surgery for retroperitoneal sarcomas: A systematic review and meta-analysis

Background

Definitive evidence to guide clinical practice on the principles of surgery for retroperitoneal sarcomas (RPSs) is still lacking. This study aims to summarise the available evidence to assess the relative benefits and disadvantages of an aggressive surgical approach with contiguous organ resection in patients with RPS, the association between surgical resection margins and survival outcomes, and the role of surgery in recurrent RPS.

Methods

We searched PubMed, the Cochrane Library, and EMBASE for relevant randomised trials and observational studies published from inception up to May 1, 2021. Prospective or retrospective studies, published in the English language, providing outcome data with surgical treatment in patients with RPS were selected. The primary outcome was overall survival (OS).

Findings

In total, 47 articles were analysed. There were no significant differences in the rates of OS (HR: 0.93; 95% CI: 0.83–1.03; P = 0.574) and recurrence-free survival (HR: 1.00; 95% CI: 0.74–1.27; P = 0.945) between the extended resection group and the tumour resection alone group. Organ resection did not increase postoperative mortality (OR: 1.00; 95% CI: 0.55–1.81; P = 0.997) but had a relatively higher complication rate (OR: 2.24, 95% CI: 0.94–5.34; P = 0.068). OS was higher in R0 than in R1 resection (HR: 1.34; 95% CI: 1.23–1.44; P < 0.001) and in R1 resection than in R2 resection (HR: 1.86; 95% CI: 1.35–2.36; P < 0.001). OS was also higher in R2 resection than in no surgery (HR: 1.26; 95% CI: 1.07–1.45; P < 0.001), however, subgroup analysis showed that the pooled HR in the trials reporting primary RPS was similar between the two groups (HR, 1.14; 95% CI, 0.87–1.42; P = 0.42). Surgical treatment achieves a significantly higher OS rate than does conservative treatment (HR: 2.42; 95% CI: 1.21–3.64; P < 0.001) for recurrent RPS.

Conclusions

For primary RPS, curative-intent en bloc resection should be aimed, and adjacent organs with evidence of direct invasion must be resected to avoid R2 resection. For recurrent RPS, surgical resection should be considered as a priority. Incomplete resection remains to have a survival benefit in select patients with unresectable recurrent RPS.

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.

Impact of time to first relapse on long-term outcome in adult retroperitoneal sarcoma patients after radical resection

BACKGROUND

Local recurrence of primary retroperitoneal sarcoma (RPS) is one of the major causes of treatment failure and death. We attempted to assess the effects of time to local recurrence (TLR) on the survival after recurrence (SAR) and overall survival (OS) of RPS.

METHODS

Included in this study were 224 patients who underwent R0 resection for primary RPS at our institution between January 2000 and December 2020, 118 of whom had local recurrence. Based on the median TLR (19.8 months), patients were divided into two groups: early local recurrence (ELR < 20 months) and late local recurrence (LLR > 20 months). The Kaplan-Meier method was employed to calculate the local recurrence-free survival (LRFS), SAR and OS. Univariate and multivariate analyses were conducted to explore the prognostic value of TLR.

RESULTS

The median follow-up time was 60.5 months for the entire cohort and 58.5 months for the recurrence cohort. There were 60 (50.8%) patients in the ELR group and 58 (49.2%) in the LLR group. The ELR group exhibited a worse SAR (29.2 months vs. 73.4 months, P < 0.001), OS (41.8 months vs. 120.9 months, P < 0.001), and a lower 5-year OS rate (35.9% vs. 73.2%, P = 0.004) than the LLR group. Furthermore, multivariate analysis indicated that TLR was an independent prognostic indicator for SAR (P = 0.014) and OS (P < 0.001).

CONCLUSIONS

In patients with RPS, ELR after R0 resection presents adverse effects on OS and SAR than those with LLR, and TLR could serve as a promising predictor for OS and SAR.

The Role of Preoperative 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Retroperitoneal Sarcoma

¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) was used to predict pathologic grades based on the maximum standardized uptake value (SUVmax) in soft tissue sarcoma and bone sarcoma. In retroperitoneal sarcoma (RPS), the effectiveness of PET was not well known. This study was designed to investigate the association of SUVmax with histopathologic grade and evaluate the usefulness of ¹⁸F-FDG PET/CT before operation. Patients at Samsung Medical Center undergoing primary surgery for retroperitoneal sarcoma with preoperative ¹⁸F-FDG PET/CT imaging between January 2001 and February 2020 were investigated. The relationship between SUVmax and histologic features was assessed. The association of SUVmax with overall survival (OS), local recurrence (LR), and distant metastasis (DM) were studied. Of the total 129 patients, the most common histologic subtypes were liposarcoma (LPS; 68.2%) and leiomyosarcoma (LMS; 15.5%). The median SUVmax was 4.5 (range, 1- 29). Moreover, SUVmax was correlated with tumor grade (p < 0.001, Spearman coefficient; 0.627) and mitosis (p < 0.001, Spearman coefficient; 0.564) and showed a higher value in LMS (12.04 ± 6.73) than in dedifferentiated liposarcoma (DDLPS; 6.32 ± 4.97, p = 0.0054). SUVmax was correlated with pathologic parameters (tumor grade and mitosis) in RPS and was higher in the LMS group than the DDLPS group. The optimal SUVmax threshold to distinguish high tumor grade was 4.8. Those with a SUVmax greater than the threshold showed poor prognosis regarding OS, LR, and DM (p < 0.001).

Ultrasound-Guided Trans-Uterine Cavity Core Needle Biopsy of Uterine Myometrial Tumors to Differentiate Sarcoma from a Benign Lesion—Description of the Method and Review of the Literature

Uterine sarcomas are rare, aggressive tumors with poor prognosis that can be further negatively affected by inadequate surgical approaches such as morcellation. There are no clinical and radiologic criteria for differentiating leiomyoma from malignant uterine tumors. However, some ultrasonography and magnetic resonance imaging findings may be informative. We present a technique of ultrasound-guided trans-uterine cavity (UG-TUC) core needle biopsy for uterine lesions. As the procedure is an in-organ biopsy, there is no risk of needle canal contamination. The technique also enables the biopsy of lesions inaccessible by the transvaginal tru-cut biopsy. The core needle of the automatic biopsy system is inserted via the cervical canal into the uterine cavity and is directed and activated at the myometrial lesion under ultrasound control. The standard local treatment of localized uterine sarcomas is en bloc total hysterectomy; for fibroids, there are multiple options including conservative management or tumorectomy and tumor morcellation using minimally invasive techniques. Fragmentation of the sarcoma significantly worsens oncologic outcomes and should therefore be avoided. The UG-TUC core needle biopsy of uterine lesions can complement imaging to obtain sufficient material for histologic and molecular analyses of suspected or undetermined lesions, thus facilitating treatment planning and decreasing the risk of unsuspected sarcomas.

The Role of Surgical Expertise and Surgical Access in Retroperitoneal Sarcoma Resection – A Retrospective Study

Background

Retroperitoneal sarcoma (RPS) is a rare disease often requiring multi-visceral and wide margin resections for which a resection in a sarcoma center is advised. Midline incision seems to be the access of choice. However, up to now there is no evidence for the best surgical access. This study aimed to analyze the oncological outcome according to the surgical expertise and also the incision used for the resection.

Methods

All patients treated for RPS between 2007 and 2018 at the Department of Visceral Surgery and Medicine of the University Hospital Bern and receiving a RPS resection in curative intent were included. Patient- and treatment specific factors as well as local recurrence-free, disease-free and overall survival were analyzed in correlation to the hospital type where the resection occurred.

Results

Thirty-five patients were treated for RPS at our center. The majority received their primary RPS resection at a sarcoma center (SC = 23) the rest of the resection were performed in a non-sarcoma center (non-SC = 12). Median tumor size was 24 cm. Resections were performed via a midline laparotomy (ML = 31) or flank incision (FI = 4). All patients with a primary FI (n = 4) were operated in a non-SC (p = 0.003). No patient operated at a non-SC received a multivisceral resection (p = 0.004). Incomplete resection (R2) was observed more often when resection was done in a non-SC (p = 0.013). Resection at a non-SC was significantly associated with worse recurrence-free survival and disease-free survival after R0/1 resection (2 vs 17 months; Log Rank p-value = 0.02 respectively 2 vs 15 months; Log Rank p-value &lt; 0.001).

Conclusions

Resection at a non-SC is associated with more incomplete resection and worse outcome in RPS surgery. Inadequate access, such as FI, may prevent complete resection and multivisceral resection if indicated and demonstrates the importance of surgical expertise in the outcome of RPS resection.

Treatment outlines for the management of primary leiomyosarcoma of the inferior vena cava

Primary venous Leiomyosarcoma (LMSs) are extremely rare tumours with poor survival rates. Surgery is currently the only potentially curative therapy in non-metastatic disease, but it consists in challenging interventions. The authors report the experience of one single centre in the treatment of LMS and a literature overview focusing on the diverse methods of vessels repair. Outcomes achieved are also outlined.

Retroperitoneal Sarcoma Care in 2021

Soft-tissue sarcomas are biologically heterogenous tumors arising from connective tissues with over 100 subtypes. Although sarcomas account for <1% of all adult malignancies, retroperitoneal sarcomas are a distinct subgroup accounting for <10% of all sarcomatous tumors. There have been considerable advancements in the understanding and treatment of retroperitoneal sarcoma in the last decade, with standard treatment consisting of upfront primary surgical resection. The evidence surrounding the addition of radiation therapy remains controversial. There remains no standard with regards to systemic therapy, including immunotherapy. Adjunctive therapy remains largely dictated by expert consensus and preferences at individual centers or participation in clinical trials. In this 2021 review, we detail the anatomical boundaries of the retroperitoneum, clinical characteristics, contemporary standard of care and well as recent advancements in retroperitoneal sarcoma care. Ongoing international collaborations are encouraged to advance our understanding of this complex disease.

Complete resection and arterial reconstruction for primary sarcoma arising from superior mesenteric artery

In the treatment of retroperitoneal sarcoma involving major vessels, complete resection with vascular reconstruction is challenging. We describe the case of a 72-year-old man who presented with 8 months of abdominal pain. Diagnostic workup revealed occlusion of the celiac trunk and the origin of the superior mesenteric artery due to a soft tissue sarcoma. Radical resection of the tumor and vessels was performed. Guided by intraoperative angiography, arterial reconstruction was performed without mesenteric ischemia. All arterial margins were negative. At the 6-year follow-up, the patient was alive with no evidence of recurrence.