Post-relapse outcomes after primary extended resection of retroperitoneal sarcoma: A report from the Trans-Atlantic RPS Working Group

Efficacy of surgery in the management of multiple recurrences of retroperitoneal dedifferentiated liposarcoma

BACKGROUND

Retroperitoneal dedifferentiated liposarcoma is associated with a high risk of recurrence; however, treatment strategies that are more effective than surgery remain to be established. This study aimed to determine the optimal number of surgeries that would be effective for patients with recurrent disease. Furthermore, the improvement in prognosis was evaluated according to the malignancy level.

METHODS

The effect of each type of surgery on the prognosis of 118 patients with retroperitoneal dedifferentiated liposarcoma treated at the Osaka International Cancer Institute between 1997 and 2022 was investigated. Among the 118 patients, 103 underwent initial surgery, while 54 and 30 patients underwent second and third surgeries, respectively. The overall and disease-free survival rates of each group were compared using the Kaplan-Meier method, and the log-rank test was used to determine statistical significance in univariate analysis. 18F-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) was used to assess malignancy. Maximum standardized uptake values (SUVmax) of ≥ 4 and < 4 were classified as high and low malignancy, respectively.

RESULTS

The first and second surgeries resulted in a significant improvement in the overall survival rate, regardless of the malignancy level (p < 0.001); however, no significant improvement in prognosis was observed after the third surgery (p = 0.077). Low-grade malignancies are associated with a better postoperative prognosis, even in cases of recurrence. In contrast, high-grade malignancies exhibit a reduction in surgical efficacy.

CONCLUSIONS

This study highlights the importance of considering the tumor malignancy level and the patient's overall condition when deciding whether to perform repeated surgical interventions. Surgical treatment can prolong overall survival, even in patients with recurrence; however, it is advisable to assess malignancy levels when determining the suitability of surgery beyond the second recurrence.

Learning curve in retroperitoneal sarcoma surgery

INTRODUCTION

Retroperitoneal sarcoma (RPS) surgery poses unique challenges. This retrospective study aimed to analyze the learning curve (LC) in RPS surgery, assessing the relationship between surgical experience and outcomes.

MATERIALS AND METHODS

Cumulative sum (CUSUM) analysis was used to analyze 62 RPS surgeries performed by a single surgeon between 2016 and 2022 at our center.

RESULTS

The number of cases where the surgeon acted as first operator increased from 3 in 2016 to 13 in 2022. The surgeon operated with his mentor in 66.7 % of cases in 2016, whereas in 7.7 % of cases in 2022. LC consisted of 3 phases. Phase 1 (16 cases), with a negative slope, represented shorter operative time (OT) and fewer number of resected organs (RO). Phase 2 (30 cases) was the plateau phase. Phase 3 (16 cases), with a positive slope, indicated longer OT and more RO. Statistically significant differences were observed in terms of size (p = 0.003), presentation (p = 0.048), number of resected organs (p = 0.046), pattern of resection (p = 0.033), OT (p = 0.006), and length of stay (p = 0.026) between the three phases.

CONCLUSION

This study focused on the critical role of LC in RPS surgery, emphasizing its influence on outcomes. We identified three phases, highlighting the surgeon's evolution. This offers a framework for educating sarcoma surgeons and ensuring exposure to increasing surgical complexity. In discussions on sarcoma referral centers and the correlation between case volume and outcomes, this study underlines the importance of evaluating LC to distinguish surgeons qualified to manage sarcoma cases within a referral center.

Identification of NINJ1 as a novel prognostic predictor for retroperitoneal liposarcoma

BACKGROUND

Retroperitoneal liposarcoma (RPLS) is known for its propensity for local recurrence and short survival time. We aimed to identify a credible and specific prognostic biomarker for RPLS.

METHODS

Cases from The Cancer Genome Atlas (TCGA) sarcoma dataset were included as the training group. Co-expression modules were constructed using weighted gene co-expression network analysis (WGCNA) to explore associations between modules and survival. Survival analysis of hub genes was performed using the Kaplan-Meier method. In addition, independent external validation was performed on a cohort of 135 Chinese RPLS patients from the REtroperitoneal SArcoma Registry (RESAR) study (NCT03838718).

RESULTS

A total of 19 co-expression modules were constructed based on the expression levels of 26,497 RNAs in the TCGA cohort. Among these modules, the green module exhibited a positive correlation with overall survival (OS, p = 0.10) and disease-free survival (DFS, p = 0.06). Gene set enrichment analysis showed that the green module was associated with endocytosis and soft-tissue sarcomas. Survival analysis demonstrated that NINJ1, a hub gene within the green module, was positively associated with OS (p = 0.019) in the TCGA cohort. Moreover, in the validation cohort, patients with higher NINJ1 expression levels displayed a higher probability of survival for both OS (p = 0.023) and DFS (p = 0.012). Multivariable Cox analysis further confirmed the independent prognostic significance of NINJ1.

CONCLUSIONS

We here provide a foundation for the establishment of a consensus prognostic biomarker for RPLS, which should not only facilitate medical treatment but also guide the development of novel targeted drugs.

Recurrent retroperitoneal liposarcoma with multiple surgeries: a case report

Retroperitoneal liposarcoma (RPLPS) is a rare malignant tumor that is typically treated with surgical resection. However, RPLPS often has a high rate of local recurrence, making it crucial to explore new treatment options. In this report, we present the case of a middle-aged woman who experienced seven recurrences and underwent seven surgeries following the initial resection. Currently, the patient's condition remains stable after the eighth surgery. Although there have been numerous reports of RPLPS cases both domestically and internationally, instances of repeated recurrence like this are exceptionally rare. Therefore, we have gathered the patient's case data and conducted a retrospective analysis, incorporating relevant literature, to enhance the understanding of this disease among clinical practitioners.

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.

Case report: Highly response to low-dose brachytherapy in recurrent retroperitoneal leiomyosarcoma with FANCD2 frameshift mutation: a unique case study

We report a case of recurrent retroperitoneal leiomyosarcoma in a male who achieved a rapid and robust but transient clinical response to low-dose iodine-125 brachytherapy. A FANCD2 frameshift mutation was detected by gene sequencing in the cancerous tissue.

Radiation therapy for retroperitoneal sarcoma: practice patterns in North America

BACKGROUND

The addition of radiation therapy (RT) to surgery in retroperitoneal sarcoma (RPS) remains controversial. We examined practice patterns in the use of RT for patients with RPS over time in a large, national cohort.

METHODS

Patients in the National Cancer Database (2004-2017) who underwent resection of RPS were included. Trends over time for proportions were calculated using contingency tables with Cochran-Armitage Trend test.

RESULTS

Of 7,485 patients who underwent resection, 1,821 (24.3%) received RT (adjuvant: 59.9%, neoadjuvant: 40.1%). The use of RT decreased annually by < 1% (p = 0.0178). There was an average annual increase of neoadjuvant RT by 13% compared to an average annual decrease of adjuvant RT by 6% (p < 0.0001). Treatment at high-volume centers (OR 14.795, p < 0.0001) and tumor > 10 cm (OR 2.009, p = 0.001) were associated with neoadjuvant RT. In contrast liposarcomas (OR 0.574, p = 0.001) were associated with adjuvant RT. There was no statistically significant difference in overall survival between patients treated with surgery alone versus surgery and RT (p = 0.07).

CONCLUSION

In the United States, the use of RT for RPS has decreased over time, with a shift towards neoadjuvant RT. However, a large percentage of patients are still receiving adjuvant RT and this mostly occurs at low-volume hospitals.

Anesthetic managements, morbidities and mortalities in retroperitoneal sarcoma patients experiencing perioperative massive blood transfusion

Objective

Given high risks of major bleeding during retroperitoneal sarcoma(RPS) surgeries, severe complications and deaths are common to see perioperatively. Thus, effective anesthetic management is the key point to ensuring the safety of patients. This study aimed to introduce anesthesia management and mortalities in RPS patients receiving massive blood transfusions during surgeries.

Methods

Records of RPS surgeries under general anesthesia from January 2016 through December 2021 were retrospectively retrieved from our database. Patients who received massive blood transfusions (MBT) exceeding 20 units in 24h duration of operations were finally included in this study. Demographics, modalities of anesthesia management, blood loss, transfusion, peri-anesthesia biochemical tests as well as morbidities and mortalities were collected. Risk factors of postoperative 60d mortality were determined through logistic regression in uni-and multi-variety analysis using the statistics software STATA 17.0.

Results

A total of 70 patients (male 31) were included. The mean age was 50.1 ± 15.8 years. All patients received combined resections of sarcoma with involved organs under general anesthesia. Mean operation time and anesthesia time were 491.7 ± 131.1mins and 553.9 ± 132.6mins, respectively. The median intraoperative blood loss was 7000ml (IQR 5500,10000ml). Median red blood cells (RBC) and fresh frozen plasma (FFP) transfusion were 25.3u (IQR 20,28u), and 2400ml (IQR 2000,3000ml), respectively. Other blood products infusions included prothrombin complex concentrate (PCCs), fibrinogen concentrate (FC), platelet(plt) and albumin(alb) in 82.9% (58/70), 88.6% (62/70), 81.4% (57/70) and 12.9% (9/70) of patients. The postoperative severe complication rate(Clavien-Dindo grade≥3a) was 35.7%(25/70). A total of 7 patients (10%) died during the postoperative 60-day period. BMI, volumes of crystalloid infusion in anesthesia, and hemoglobin and lactate levels at the termination of operation were found significantly associated with postoperative occurrence of death in univariate analysis. In logistic multivariate analysis, extended anesthesia duration was found associated with postoperative venous thrombosis embolism (VTE) and severe complication. The lactate level at the immediate termination of the operation was the only risk factor related to perioperative death (p<0.05).

Conclusion

RPS patients who endure MBT in surgeries face higher risks of death postoperatively, which needs precise and effective anesthesia management in high-volume RPS centers. Increased blood lactate levels might be predictors of postoperative deaths which should be noted.

Does compartmental resection really impact retroperitoneal soft tissue sarcomas? A retrospective analysis from a Single Referral Center

BACKGROUND

The treatment of choice for retroperitoneal soft tissue sarcomas (RPS) is surgical resection; the outcomes with more radical surgeries, notably compartmental resection, remains a subject of debate. Arguments against it, include the complexity of the technique and high morbidity.

MATERIALS AND METHODS

A retrospective analysis of cases treated in a single center from January 2010 to December 2019 is presented. Two time periods were evaluated: 2010-2015 and 2016-2019, corresponding to before and after the implementation of routine compartmentectomy. We evaluated the short- and long-term outcomes of compartmental resection compared to limited surgeries through a multivariate analysis of prognostic factors.

RESULTS

A total of 176 cases were included, of which 102 met the inclusion criteria. The sex distribution was similar. The average age was 52.9 years, and the average tumor size was 24.5 cm. The most frequent histology was liposarcoma (65.7%), followed by leiomyosarcoma (12.7%), and malignant peripheral nerve sheath tumor (8.8%). The median follow-up period was 40 months. We found a lower local recurrence in the group treated in the recent period (compartmentectomy) 42.3% vs 20% p = 0.007. The median overall survival (OS) was 38.7 months, and there was no difference in distant recurrence between the two time periods. Postoperative morbidity was higher in the recent period (25% vs 10% p 0.041), with no difference in 30-day mortality.

CONCLUSIONS

The implementation of extensive surgery, specifically compartmentectomy, for retroperitoneal sarcomas has been linked to reduced local recurrence. We recommend considering this surgical approach for RPS in alignment with current expert consensus guidelines, as highlighted by the updated TARPSWG consensus.

Long-term quality of life after resection of retroperitoneal soft tissue sarcoma

INTRODUCTION

Retroperitoneal soft tissue sarcoma (RPS) is characterized by high recurrence rates. Since complete tumor resection, often necessitating multivisceral resection, enables long-term survival in both primary and recurrent disease, health related quality of life (QoL) after RPS resection has attracted increasing interest. However, data regarding this topic is limited. Here, we multidimensionally assessed long-term QoL after RPS resection.

METHODS

Five previously validated (1. EORTC QLQ-C30, 2. WEMWBS, 3. FoP-Q-SF, 4. PC-PTSD, 5. Pro-CTCAE) were sent to patients having undergone resection of primary, recurrent and metastasized RPS at Heidelberg University Hospital between 10/2001 and 12/2020. Multivariable linear regression models were used to test associations between clinical/demographic variables and patient reported outcomes (PROs).

RESULTS

Questionnaires were answered by 127 patients (71% response rate). The median interval between RPS diagnosis and assessment of PROs was 80 months. The overall Global Health score was 64.1 and comparable to the general German population. RPS patients reported deficits regarding emotional and social functioning, whereas physical limitations were less pronounced. Besides diarrhea, abdominal symptoms were comparable to the overall population. Tumor recurrences, the number of surgeries, multivisceral resections or postoperative complications did not significantly affect long-term QoL ratings.

CONCLUSION

RPS patients rate their QoL relatively high, even after multiple and multivisceral resections. Psychosocial well-being should be monitored in follow-up sessions to offer tailored support if necessary, thus improving postoperative care.

Surgical treatment of recurrent retroperitoneal sarcoma in its different patterns: A 15-years' two-centers experience

INTRODUCTION

There is limited data available regarding the role of surgery in the treatment of retroperitoneal sarcoma (RPS) recurrences. We herein report the short- and mid-term outcomes of patients who underwent surgical treatment of RPS recurrences at two Italian centers over a 15-years' experience.

MATERIALS AND METHODS

From January 2005 to January 2020, 33 patients underwent surgical treatment of isolated locally recurrent RPS (LR group), locally recurrent RPS associated with the presence of distant recurrence (LR + DM group), and distant-only recurrent RPS (DM group). Only procedures performed to obtain a macroscopically radical treatment with curative intent were included. Data regarding pre-, intra-, post-operative course, and follow-up, collected in an Institutional database, were retrospectively analyzed, and compared.

RESULTS

LR-group was composed of 15 patients, LR + DM group of 9 patients, and DM group of 9 patients. During the follow-up, 78.5% of the LR group, 77.8% of the DM group and 100% of the LR + DM group (p = 0.244) experienced a second recurrence. 7/11 (63.6%) patients in the LR group, 2/7 (28.5%) patients in the DM-group, and 0/9 (0.0%) patients in the LR + DM group underwent to almost one further local treatments of their recurrences (p = 0.010). No differences in the mean disease-free survival (p = 0.127), overall survival (OS) (p = 0.165) was reported among the three groups. Repeated surgery was an independent factor affecting survival in multivariate analysis (p = 0.01).

CONCLUSIONS

A surgical treatment of RPS recurrences should always be taken into consideration, also in metastatic patients and/or in those who have already undergone surgery for previous RPS recurrence, because this approach may offer survival benefits.

Survival of a patient with five recurrences of retroperitoneal liposarcoma over a period of 13 years: A case report and review

Retroperitoneal liposarcoma (RPLS) is a rare tumor that occurs in the retroperitoneal region and accounts for ~0.2% of all malignant tumor incidence. The present study describes the treatment of a surviving patient with RPLS that recurred five times in 13 years. This case has a long survival time and numerous relapses, which is a rare occurrence. The 40-year-old female patient was admitted to Shaoxing Second Hospital (Shaoxing, China) with an abdominal mass. Abdominal computed tomography (CT) scan revealed multiple liposarcoma recurrences in the abdominal, pelvic and retroperitoneal areas. As the diagnosis of RPLS was the fifth recurrence, cytoreductive surgery was performed and post-operative pathology suggested mixed liposarcoma. The patient underwent six cycles of doxorubicin and ifosfamide regimen chemotherapy and targeted therapy with anlotinib following surgery; no evidence of disease progression was found on abdominal CT scan during follow-up. The present study also reviewed the literature in terms of the clinical diagnosis, treatment, pathological characteristics and similar cases of liposarcoma with the aim of improving diagnosis and treatment.

R0 surgical resection of giant dedifferentiated retroperitoneal liposarcomas in the COVID era with and without nephrectomy: A case report

Retroperitoneal sarcomas (RPSs) are rare findings that can grow into large masses without eliciting severe symptoms. At present, surgical resection is the only radical therapy, whenever it can be performed with the aim to achieve a complete removal of the tumor. The present report describes two consecutive cases of RPSs that resulted in dedifferentiated liposarcomas (DDLPSs) and these patients underwent R0 surgical resection with and without a nephron-sparing procedure. The diagnostic workup, the surgical approach, the impact of late surgical management due to the COVID pandemic and the latest literature on the topic are discussed and analyzed. The patients, who refused to undergo any medical examination during the prior 2 years due to the COVID pandemic, were admitted to Federico II University Hospital (Naples, Italy) complaining about weight loss and general abdominal discomfort. In the first case, a primitive giant abdominal right neoplasm of retroperitoneal origin enveloping and medializing the right kidney was observed. The second patient had a similar primitive retroperitoneal giant left neoplasm, which did not affect the kidney. Given the characteristics of the masses and the absence of distant metastases, after a multidisciplinary discussion, radical surgical removal was carried out for both patients. The lesions appeared well-defined from the surrounding tissues, and markedly compressed all the adjacent organs, without signs of infiltration. In the first patient, the right kidney was surrounded and undetachable from the tumor and it was removed en bloc with the mass. The second patient benefited from a nephron-sparing resection, due to the existence of a clear cleavage plane. The postoperative courses were uneventful. Both the histological examinations were oriented towards a DDLPS and both patients benefited from adjuvant chemotherapy. In conclusion, the treatment of giant RPS is still challenging and requires multidisciplinary treatment as well as, when possible, radical surgical removal. The lack of tissue infiltration and the avoidance of excision or reconstruction of major organs (including the kidney) could lead to an easier postoperative course and an improved prognosis. When possible, surgical management of recurrences or incompletely resected masses must be pursued. Since the COVID pandemic caused limited medicalization of a number of population groups and delayed diagnosis of other oncologic diseases, an increased number of DDLPSs could be expected in the near future.

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.

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

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

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.

Complex Vascular Resections for Retroperitoneal Soft Tissue Sarcoma

Retroperitoneal sarcomas (RPSs) are locally aggressive tumors that can compromise major vessels of the retroperitoneum including the inferior vena cava, aorta, or main tributary vessels. Vascular involvement can be secondary to the tumor's infiltrating growth pattern or primary vascular origin. Surgery is still the mainstay for curing this disease, and resection of RPSs may include major vascular resections to secure adequate oncologic results. Our improved knowledge in the tumor biology of RPSs, in conjunction with the growing surgical expertise in both sarcoma and vascular surgical techniques, has allowed for major vascular reconstructions within multi-visceral resections for RPSs with good perioperative results. This complex surgical approach may include the combined work of various surgical subspecialties.

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.

Management of Recurrent Retroperitoneal Sarcoma

Recurrence after resection of retroperitoneal sarcoma is common and varies by histological subtype. Pattern of recurrence is similarly affected by histology (e.g., well-differentiated liposarcoma is more likely to recur locoregionally, whereas leiomyosarcoma is more likely to develop distant metastases). Radiotherapy may provide effective locoregional control in limited circumstances and the data on the impact of chemotherapy are scant. Surgery for locally recurrent disease is associated with the greatest survival benefit; however, data are retrospective and from a highly selected subgroup of patients. Limited retrospective data have also suggested a survival association with the resection of limited distant metastases. Given the complexity of these patients, multidisciplinary evaluation at a high-volume sarcoma center is critical.

Giant retroperitoneal liposarcoma measuring 27 × 29 × 36 cm: a case report

Retroperitoneal tumors are rare neoplasms that can reach great dimensions due to a slow growth pattern. Although these tumors rarely metastasize, they have a great risk of recurrence, and majority of times these lesions are a challenge for the surgeon. We report the case of a 63-year-old woman who presented with symptoms of large bowel obstruction and was diagnosed with a large heterogenous mass located in the retroperitoneal space. The fine needle biopsy revealed the histology of liposarcoma. The purpose of this article is to report our approach in management of this kind of tumor. Tumor size (27.1 × 29.1 × 36.1 cm) and involvement to the adjacent organs was a challenge for us in order to reach safe oncological margins. In these cases, the risk of recurrence is high; therefore, the patient should be screened at 6, 12 and 24 months post procedure. Chemotherapy or radiotherapy for this tumor is not yet defined, and if operable, surgery is the treatment of choice.

Targeting the MDM2-p53 pathway in dedifferentiated liposarcoma

Dedifferentiated liposarcoma (DDLPS) is an aggressive adipogenic cancer with poor prognosis. DDLPS tumors are only modestly sensitive to chemotherapy and radiation, and there is a need for more effective therapies. Genetically, DDLPS is characterized by a low tumor mutational burden and frequent chromosomal structural abnormalities including amplification of the 12q13-15 chromosomal region and the MDM2 gene, which are defining features of DDLPS. The MDM2 protein is an E3 ubiquitin ligase that targets the tumor suppressor, p53, for proteasomal degradation. MDM2 amplification or overexpression in human malignancies is associated with cell-cycle progression and worse prognosis. The MDM2-p53 interaction has thus garnered interest as a therapeutic target for DDLPS and other malignancies. MDM2 binds p53 via a hydrophobic protein interaction that is easily accessible with synthetic analogues. Multiple agents have been developed, including Nutlins such as RG7112 and small molecular inhibitors including SAR405838 and HDM201. Preclinical in vitro and animal models have shown promising results with MDM2 inhibition, resulting in robust p53 reactivation and cancer cell death. However, multiple early-phase clinical trials have failed to show a benefit with MDM2 pathway inhibition for DDLPS. Mechanisms of resistance are being elucidated, and novel inhibitors and combination therapies are currently under investigation. This review provides an overview of these strategies for targeting MDM2 in DDLPS.

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

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

Retroperitoneal Sarcomas: a Current Review on Management

Retroperitoneal sarcomas are heterogeneous tumours with variable disease biology and outcomes. The prognosis is primarily related to tumour histology and grade as well as the ability to achieve margin negative resection. Surgery involves compartment or contiguous organ resection to achieve the above goal. Careful utilization of neoadjuvant and adjuvant strategies like radiotherapy and/or chemotherapy can lead to improvement in margin status, thereby contributing to better local control and possibly reducing systemic dissemination. Use of targeted therapies has paved newer pathways of treatment integration centred on molecular and genetic targets. The aim of this review is to update the reader on all aspects of retroperitoneal sarcoma management including emphasis on pertinent and landmark trials in this regard.

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.

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.

First and further-line multidisciplinary treatment of retroperitoneal sarcomas

PURPOSE OF REVIEW

To review current knowledge and recent advances in retroperitoneal sarcoma management.

RECENT FINDINGS

Surgery, radiotherapy, and medical treatments of retroperitoneal sarcomas should take into account the peculiarities of each histotype and the unique anatomical site. Surgery remains the mainstay of treatment and the only chance of cure for these diseases. In low-grade retroperitoneal sarcomas, like well differentiated liposarcoma, where the leading cause of death is dominated by local rather than distant relapses, treatment of the primary tumor encompasses extended surgery with multiorgan resection and evaluation of preoperative radiotherapy. Conversely, surgery is usually more conservative and without radiotherapy in those retroperitoneal sarcomas, such as leiomyosarcoma, characterized by a high risk of metastatic spread that prompted also the evaluation of neoadjuvant, histotype-driven chemotherapy. Surgery might have a role also for relapsed disease, despite long-term disease control probability declines at each recurrence. In advanced stages, anthracyclines still retain a key role and all medical treatment strategies should follow the specific chemosensitivity of each histotype to improve patient's outcomes.

SUMMARY

The rarity and heterogeneity in biological behavior and clinical presentation of retroperitoneal sarcomas deserves a multidisciplinary and histotype-driven treatment at all stages of the disease to be performed in highly specialized centers.

Retroperitoneal and Mesenteric Liposarcomas

Retroperitoneal liposarcomas are a rare entity and are comprised mostly of the well-differentiated and dedifferentiated subtypes. Eight-year survival ranges from 30% to 80% depending on histologic subtype and grade. Surgery is the cornerstone of treatment and compartment resection is the current standard. Mesenteric liposarcomas are extremely rare and comprise more high-grade lesions, with poorer prognosis of 50% 5-year overall survival. They are managed with a similar aggressive surgical approach. This review presents the current management of retroperitoneal and mesenteric liposarcomas.

Analysis of the Effect of Tumor-Grade Change on the Prognosis of Retroperitoneal Sarcoma

Simple Summary

Changes in tumor differentiation have been observed during local recurrence in retroperitoneal sarcoma (RPS), and these changes have been reported to affect prognosis. However, the change in the tumor grade from the primary tumor to the first local recurrence, and the effect of this change on long-term outcomes, are unknown. This study reports the presence of tumor-grade changes and their effect on patient prognosis. While the grade changes did not affect the patient’s prognosis, a high grade of the primary tumor was an important factor. In addition, the risk factor for second local recurrence was a high grade of the recurrent tumor. Although this finding cannot change the treatment plan for recurrent RPS, it can provide the details of nomograms to predict the patient prognosis.

Abstract

In retroperitoneal sarcoma (RPS), the change in the tumor grade from the primary tumor to the first local recurrence, and the effect of this change on prognosis, are unknown. The aim of this study is to analyze whether these changes affect the prognosis of RPS. Patients who underwent surgery for a first locally recurrent RPS at Samsung Medical Center from January 2001 to February 2020 were included. The pathologic features of primary and recurrent tumors were compared, and the outcomes were measured. A total of 49 patients were investigated. There were 25 patients with different grades of primary and recurrent tumors. The improving, stable, and worsening groups contained 16 (32.7%), 24 (49%), and 9 (18.3%) patients, respectively. There was no significant difference in the prognosis between the three groups. In the analyses of the factors that affect the OS, a high grade of the primary tumor (p = 0.023) and the size of the recurrent tumor (p = 0.032) were statistically significant in both univariate and multivariate analyses. In a factor analysis of the second LR, a high-grade recurrent tumor (p = 0.032) was the only significant factor. There were tumor-grade changes between the primary tumor and recurrent tumor in RPS. However, the most important factor in prognosis is a high grade of the primary tumor.

Real-world use of palbociclib monotherapy in retroperitoneal liposarcomas at a large volume sarcoma center

Palbociclib has been evaluated in early phase trials for well-differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS) patients, with reported median progression-free survival (PFS) of 18 weeks. Here, we report on real-world use and surgical outcomes associated with palbociclib treatment. We retrospectively reviewed 61 consecutive patients with retroperitoneal WDLPS (n = 14) or DDLPS (n = 47) treated with palbociclib monotherapy between 1 March 2016 and 28 February 2021 at The University of Texas MD Anderson Cancer Center. At palbociclib initiation, median age was 64 (interquartile range [IQR] 56-72). In WDLPS and DDLPS cohorts, the median number of prior systemic treatments was 0 (IQR 0-0) and 2 (IQR 0-4), respectively. Median number of prior surgeries was 2 (WDLPS IQR 1-2.75) and 2 (DDLPS IQR 1-3). Median PFS was 9.2 (WDLPS IQR 3.9-21.9) and 2.6 months (DDLPS IQR 2.0-6.1), with median time on treatment of 7.4 months (WDLPS IQR 3.5-14.2) and 2.7 months (DDLPS IQR 2.0-5.7). Twelve patients ultimately underwent surgical resection. Resections were macroscopically complete (R0/R1) in half (n = 6/12), among whom only one patient experienced relapse after resection (median follow-up 7.5 months). All patients who underwent macroscopically incomplete resections progressed after surgery with median time to progression of 3.3 months (IQR 2.3-4.4). Surgery after palbociclib treatment was not associated with improved overall survival. Efficacy of palbociclib monotherapy for patients with advanced WDLPS and DDLPS is disappointing. While palbociclib may have been used to delay surgery, there was no clear benefit from treatment and few patients achieved prolonged tumor control.

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.

Comparison of preoperative chemoradiation with radiation or chemotherapy alone in patients with non-metastatic, resectable retroperitoneal sarcoma

Aim:

Optimal preoperative therapy regimen in the treatment of resectable retroperitoneal sarcoma (RPS) remains unclear. This study compares the impact of preoperative radiation, chemoradiation and chemotherapy on overall survival (OS) in RPS patients.

Materials and Methods:

The National Cancer Database (NCDB) was queried for patients with non-metastatic, resectable RPS (2006–15). The primary endpoint was OS, evaluated by Kaplan–Meier method, log-rank test, Cox multivariable analysis and propensity score matching.

Results:

A total of 1,253 patients met the inclusion criteria, with 210 patients (17%) receiving chemoradiation, 850 patients (68%) receiving radiation and 193 patients (15%) receiving chemotherapy. On Cox multivariable analysis, when compared to preoperative chemoradiation, preoperative radiation was not associated with improved OS (hazards ratio [HR] 0·98, 95% CI 0·76–1·25, p = 0·84), while preoperative chemotherapy was associated with worse OS (HR 1·64, 95% CI 1·24–2·18, p < 0·001). Similar findings were observed in 199 and 128 matched pairs for preoperative radiation and chemotherapy, respectively, when compared to preoperative chemoradiation.

Findings:

Our study suggested an OS benefit in using preoperative chemoradiation compared to chemotherapy alone, but OS outcomes were comparable between preoperative chemoradiation and radiation alone.

[Retroperitoneal soft tissue sarcoma: surgical management]

BACKGROUND

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS AND CONCLUSION

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

Longitudinal prognostication in retroperitoneal sarcoma survivors: Development and external validation of two dynamic nomograms

PURPOSE

The aim of this study was to create and validate dynamic nomograms to predict overall survival (OS) and disease-free survival (DFS) at different time points during follow-up in patients who had undergone resection of primary retroperitoneal sarcoma (RPS).

METHODS

Patients with primary RPS operated upon between 2002 and 2017 at four and six referral centres comprised the development and external validation cohorts, respectively. Landmark analysis and multivariable Cox models were used to develop dynamic nomograms. Variables were selected using two backward procedures based on the Akaike information criterion. The prediction window was fixed at 5 years. Nomogram performances were tested in terms of calibration and discrimination on the development and validation cohorts.

RESULTS

Development and validation cohorts totalled 1357 and 487 patients (OS analysis), and 1309 and 452 patients (DFS analysis), respectively. The final OS model included age, landmark time (T_LM), tumour grade, completeness of resection and occurrence of local/distant recurrence. The final DFS model included T_LM, histologic subtype, tumour size, tumour grade, multifocality and the interaction terms between T_LM and size, grade and multifocality. For OS, Harrell C indices were higher than 0.7 in both cohorts, indicating very good discriminative capability. For DFS, Harrell C indices were between 0.64 and 0.72 in the development cohort and 0.62 and 0.68 in the validation cohort. Calibration plots showed good agreement between predicted and observed outcomes.

CONCLUSION

Validated nomograms are available to predict the 5-year OS and DFS probability at different time points throughout the first 5 years of follow-up in RPS survivors.

18F-Fluorodeoxyglucose Positron Emission Tomography Is Useful in the Evaluation of Prognosis in Retroperitoneal Sarcoma

Simple Summary

Retroperitoneal sarcomas are difficult malignancies to treat because complete surgical resection is the only effective treatment option, but it is difficult to secure sufficient surgical margins. It is essential for developing a treatment strategy to assess tumor aggressiveness and predict prognosis for patients. However, the aggressiveness of retroperitoneal sarcomas before treatment cannot be fully evaluated. In patients with resectable soft tissue sarcomas or several carcinomas, SUV evaluated with FDG-PET has been reported to be a valuable prognostic parameter. However, the correlation between SUVmax on FDG-PET and the prognosis of several histological subtypes in retroperitoneal sarcoma, including dedifferentiated liposarcoma, well-differentiated liposarcoma, and leiomyosarcoma, remains uncertain. This study revealed that SUVmax calculated with FDG-PET was useful as a prognostic factor in retroperitoneal sarcoma, especially in dedifferentiated liposarcoma and Grade2 retroperitoneal sarcoma.

Abstract

Background: Retroperitoneal sarcomas are rare neoplasms that occur in the retroperitoneum. Complete surgical resection is the only effective treatment option. The prediction of prognosis by histological diagnosis has not yet been established. The purpose of this study was to identify the usefulness of [18-F] fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging for validating the prognosis of retroperitoneal sarcoma (RPS) established by histological diagnosis. Methods: We retrospectively reviewed 201 patients with RPS treated at the Osaka International Cancer Institute between 2010 and 2021. We extracted the clinical data, including standardized uptake values (SUVs), evaluated with FDG-PET, and statistically analyzed the data. Results: The median age of patients was 64 years (range, 31–85 years). A total of 101 (50.2%) patients were men, and 100 (49.8%) were women. Surgical resection was performed in 155 (77.1%) patients. On histological analysis, 75 (37.3%), 52 (25.9%), and 29 (14.4%) patients were diagnosed with dedifferentiated liposarcoma, well-differentiated liposarcoma, and leiomyosarcoma, respectively. The median survival time for patients with high maximum SUV (SUVmax) (≥4) or low SUVmax (<4) was 275.8 months and 79.5 months, respectively. Furthermore, among the patients with dedifferentiated liposarcoma, the overall survival rate for patients with high SUVmax (≥4) was significantly lower than that of those with low SUVmax (<4). Conclusions: The present study demonstrated that SUVmax calculated with FDG-PET was useful as a prognostic factor in RPS, especially in dedifferentiated liposarcoma and Grade2 RPS. To devise a treatment strategy for RPS, SUVmax during FDG-PET scan may be considered for clinical assessment.

Initial Clinical Experience With Novel Directional Low-dose Rate Brachytherapy for Retroperitoneal Sarcoma

BACKGROUND

A novel Palladium-103 low-dose rate (LDR) brachytherapy device was developed to provide dose-escalation to the tumor bed after resection while shielding adjacent tissues. This multicenter report describes the initial experience with this device in patients with retroperitoneal sarcoma (RPS).

MATERIALS AND METHODS

Patients with recurrent RPS, prior radiotherapy, and/or concern for positive margins were considered. An LDR brachytherapy dose of 20-60 Gy was administered, corresponding to biologically effective dose values of 15-53 Gy and equivalent dose values of 12-43 Gy.

RESULTS

Six patients underwent implantation at four institutions. Of these, five had recurrent disease in the retroperitoneum or pelvic sidewall, one had untreated locally advanced leiomyosarcoma, two had prior external beam radiation therapy at the time of initial diagnosis, and four received neoadjuvant external beam radiation therapy plus brachytherapy. The device was easily implanted and conformed to the treatment area. Median follow-up was 16 mo; radiation was delivered to the at-risk margin with minimal irradiation of adjacent structures. No local recurrences at the site of implantation, device migration, or radiation-related toxicities were observed.

CONCLUSIONS

The novel LDR directional brachytherapy device successfully delivered a targeted dose escalation to treat RPS high-risk margins. Lack of radiation-related toxicity demonstrates its safety.

Retroperitoneal sarcoma: the Transatlantic Australasian Retroperitoneal Sarcoma Working Group Program

PURPOSE OF REVIEW

The Transatlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) is a bottom-up clinical network established in 2013 with the goal of improving the care and outcomes of patients with retroperitoneal sarcoma (RPS). Here, we review the knowledge produced by this collaborative effort and examine the future potential of this group.

RECENT FINDINGS

TARPSWG has produced retrospective studies focused on patients with primary and recurrent RPS allowing a better understanding of patient prognosis, treatment outcomes and tumor biology. The group has played a pivotal role in a phase III randomized STudy of preoperative RAdiotherapy plus Surgery versus surgery alone for patients with Retroperitoneal Sarcoma (STRASS) trial, favoring patient recruitment and trial completion. A prospective registry for patients with primary RPS populated by TARPSWG members is ongoing. TARPSWG has created consensus papers with recommendations regarding the management of patients with primary, recurrent and metastatic RPS that collated the views of representatives of sarcoma centers from Europe, North America, Asia and Australia.

SUMMARY

Since its inception, TARPSWG has become a leading network in the field of RPS. It has made a major contribution to the world of RPS research and cares allowing to overcome the limitations related to the rarity of the disease through collaboration.

[French ccAFU guidelines - update 2020-2022: retroperitoneal sarcoma]

OBJECTIVE

- To update French urological guidelines on retroperitoneal sarcoma.

MATERIALS AND METHODS

- Comprehensive Medline search between 2018 and 2020 upon diagnosis, treatment and follow-up of retroperitoneal sarcoma. Level of evidence was evaluated.

RESULTS

- Chest, abdomen and pelvis CT is mandatory to evaluate any suspected retroperitoneal sarcoma. MRI sometimes helps surgical planning. Before histological confirmation through biopsy, the patient must be registered in the French sarcoma pathology reference network. The biopsy standard should be an extraperitoneal coaxial percutaneous sampling before any retroperitoneal mass therapeutic decision. Surgery is retroperitoneal sarcoma cornerstone. The main objective is grossly negative margins and can be technically challenging. Multimodal treatment risks and benefits must be discussed in multidisciplinary teams. The relapse rate is related to tumor grade and surgical margins. Reported Negative margins rate thus encourage surgery in high-volume centers.

CONCLUSION

- Retroperitoneal sarcoma prognosis is poor and closely related to the quality of initial management. Centralization through dedicated sarcoma pathology network in a high-volume center is mandatory.

Surgery in soft tissue sarcoma: the thin line between a surgical or more conservative approach

Surgery is the primary treatment for localized, clinically resectable soft tissue sarcoma (STS). Chemotherapy and radiotherapy, administered in the pre- or post-operative settings, have important ancillary roles in the multimodal management of primary STS. Some sarcoma centers also employ locoregional therapies such as isolated limb perfusion and deep wave hyperthermia in multimodal therapy. In advanced or metastatic STS, surgery is recommended when complete resection is feasible. Nevertheless, in certain situations there is thin line between a surgical or non-surgical approach, generally related to STS histological type/subtype, disease stage and technical considerations. In advanced STS, factors favoring surgery are isolated oligometastatic disease, long disease-free interval, suitable histology, response to chemotherapy and high probability of a complete resection.

Outcome after surgical resection of multiple recurrent retroperitoneal soft tissue sarcoma

INTRODUCTION

Local recurrences (LR) and distant metastases (DM) are common in retroperitoneal soft tissue sarcoma (RPS). Longer time to recurrence and resection of the recurrent lesion have been identified as beneficial prognostic factors for overall survival (OS) upon first tumor relapse. However, prognostic factors concerning OS upon subsequent recurrences are scarcely defined. In this study, we aimed to identify prognostic factors for post-relapse outcome in multiple recurrent RPS.

METHODS

Patients undergoing resection of primary and recurrent RPS at the University Hospital Heidelberg were retrospectively analyzed. Multivariable Cox regression analyses were performed to identify predictors of overall, LR- and DM-free survival. Subgroup analyses were performed for liposarcoma and leiomyosarcoma patients.

RESULTS

201 patients with primary disease, 101 patients with first, 66 patients with second and 43 patients with third LR as well as 75 patients with DM were analyzed. More than 12 months to recurrence and resection of recurrence were associated with improved OS after resection of first and second LR (5-year OS for first/second LR; resection: 64%/62%, no resection: 20%/46%). Gross macroscopic incomplete resection of first (p < 0.001), second (p = 0.001), and third recurrences (p < 0.001) was an independent prognostic factor for poor OS.

CONCLUSION

Development of LR and DM is frequent in RPS. Once a tumor relapsed, patients benefit from tumor resection not only in case of first, but also in case of subsequent recurrences.

Long-term survival by repeat resection for metastases from primary retroperitoneal leiomyosarcoma: A case report

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Retroperitoneal (RP) leiomyosarcoma (LMS) is rare, with a high recurrence rate.

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A woman with RP LMS underwent over 20 surgeries for recurrence over 24 years.

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Long-term survival of 29 years was achieved after these resections.

•

Aggressive and radical repeat resections may be beneficial in such patients.

Backgound

Retroperitoneal (RP) leiomyosarcoma (LMS) is a rare type of cancer, accounting for 0.1% of all malignancies. The gold-standard treatment for sarcoma is complete resection, and a 50% 5-year overall survival (OS) rate can be achieved by curative surgery. The survival benefits of radiotherapy and systemic chemotherapy for recurrence are not as good as those of surgical resection. To the best of our knowledge, there are a few reports that aggressive radical surgery significantly prolonged the survival period as our case. This case was reported in accordance with the SCARE 2020 Guideline (Ref).

Case presentation

An 84-year-old woman was referred to our hospital for treatment of a primary RP tumour. At the age of 52-year-old, she underwent complete resection of an RP mass in 1991. Twenty-four years after the primary resection, metachronous recurrences occurred within the soft tissues, which were repeatedly resected. From 2015–2019, liver resections were performed thrice, and the patient survived with no signs of recurrence 1 year after the last surgery.

Conclusion

Long-term survival of 29 years was achieved after undergoing over 20 surgical resections. Herein, we report the long-term survival of a patient who underwent repeated aggressive surgical resections for RP LMS recurrence anda literature review.

Major vascular resection in retroperitoneal sarcoma surgery

Major blood vessels may be invaded either by primary sarcomas arising from the vessel wall or by secondary infiltration of a retroperitoneal sarcoma. The involvement of major blood vessels is not considered to be an absolute contraindication for surgical resection. The main issue when evaluating a possible major vascular resection is to balance the possible surgical morbidity with the expected survival benefit. This is strictly related to the tumor's biology and clinical behavior and to the patient's performance status and comorbidities. A multidisciplinary approach in a specialized center is mandatory when approaching a possible oncovascular resection for retroperitoneal sarcoma, given the rarity and the heterogeneity of these tumors.

Multiple well-differentiated retroperitoneal liposarcomas with different patterns of appearance on computed tomography: A case report

BACKGROUND

Primary retroperitoneal liposarcoma (PRPLS) is a rare soft tissue tumor with nonspecific clinical symptoms; it has different computed tomography (CT) image features according to pathological types. Some patients with a single tumor have been previously reported in the literature. We present an exceptional case of a PRPLS patient with multiple large tumors exhibiting different patterns of appearance on CT and confirmed as atypical lipomatous tumor/well-differentiated liposarcoma by postoperative pathology.

CASE SUMMARY

A 64-year-old man presented with abdominal distension for 1 year. The patient was diagnosed with PRPLS based on physical examination, laparotomy, ultrasonography, CT scan, and surgery. Both of the tumors were completely resected through surgery and confirmed as atypical lipomatous tumor/well-differentiated liposarcoma by postoperative pathology. The postoperative course was uneventful without recurrence or metastasis, as demonstrated by abdominal-pelvic CT during an 18 mo follow-up.

CONCLUSION

Multiple large Well-differentiated liposarcomas with different patterns of appearance on CT image can occur simultaneously in the same patient, to which more attention should be paid to make an effective differential diagnosis.

Long-Term Survival of a Patient with Recurrent Dedifferentiated High-Grade Liposarcoma of the Retroperitoneum Under Adjuvant Treatment with Viscum album L. Extract: A Case Report

Retroperitoneal sarcomas are rare. Dedifferentiated liposarcomas (DDLs) are high-grade tumors with a high propensity for local recurrence and metastasis and are associated with reduced survival. Radical resection remains the standard treatment of sarcomas. Meanwhile, Viscum album L. extract (VAE) is used in cancer patients owing to its cytostatic and immunomodulating effects and to its ability to improve patients’ quality of life.

Retroperitoneal teratoma resection assisted by 3-dimensional visualization and virtual reality: A case report

BACKGROUND

Primary retroperitoneal tumor is a rare type of tumor with insidious onset, large tumor size at the time of diagnosis, and often extensive involvement of surrounding tissues and blood vessels in the retroperitoneum. Surgery for primary retroperitoneal tumors is technically challenging. Preoperative imaging evaluation is critical for the selection of the optimal surgical approach and can influence complete resection and recurrence rates. Three-dimensional model reconstruction combined with virtual reality is useful for preoperative assessment.

CASE SUMMARY

A 17-year-old female patient was admitted for abdominal pain lasting for half a year that had been worsening for half a month. Abdominopelvic enhanced helical computed tomography revealed a retroperitoneal space-occupying lesion about 11.3 cm × 9.1 cm in size, with well-defined borders in the upper left quadrant of the abdomen. The lesion compressed the left renal artery and vein resulting in vascular displacement and deformation. A multidisciplinary team decided on the optimal treatment approach. Preoperative three-dimensional visualization and virtual reality technology were used to assess and simulate the surgical procedure. Then, retroperitoneal tumor resection along with renal artery reconstruction was decided as the treatment. Complete resection of the retroperitoneal tumor was performed. Stable blood flow was established after renal artery reconstruction. The tumor was diagnosed as mature cystic teratoma (retroperitoneal tumor) by postoperative pathologic analysis. The patient, who recovered well, was discharged after 2 wk and maintains regular follow-ups.

CONCLUSION

A combination of three-dimensional reconstruction and virtual reality technology before surgery improves the rate of complete resection of retroperitoneal teratoma.

Postoperative Morbidity After Resection of Recurrent Retroperitoneal Sarcoma: A Report from the Transatlantic Australasian RPS Working Group (TARPSWG)

BACKGROUND

This study aimed to evaluate perioperative morbidity after surgery for first locally recurrent (LR1) retroperitoneal sarcoma (RPS). Data concerning the safety of resecting recurrent RPS are lacking.

METHODS

Data were collected on all patients undergoing resection of RPS-LR1 at 22 Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) centers from 2002 to 2011. Uni- and multivariable logistic models were fitted to study the association between major (Clavien-Dindo grade ≥ 3) complications and patient/surgery characteristics as well as outcome. The resected organ score, a method of standardizing the number of organs resected, as previously described by the TARPSWG, was used.

RESULTS

The 681 patients in this study had a median age of 59 years, and 51.8% were female. The most common histologic subtype was de-differentiated liposarcoma (43%), the median resected organ score was 1, and 83.3% of the patients achieved an R0 or R1 resection. Major complications occurred for 16% of the patients, and the 90-day mortality rate was 0.4%. In the multivariable analysis, a transfusion requirement was found to be a significant predictor of major complications (p < 0.001) and worse overall survival (OS) (p = 0.010). However, having a major complication was not associated with a worse OS or a higher incidence of local recurrence or distant metastasis.

CONCLUSIONS

A surgical approach to recurrent RPS is relatively safe and comparable with primary RPS in terms of complications and postoperative mortality when performed at specialized sarcoma centers. Because alternative effective therapies still are lacking, when indicated, resection of a recurrent RPS is a reasonable option. Every effort should be made to minimize the need for blood transfusions.

Primary mesenteric sarcomas: Collaborative experience from the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG)

BACKGROUND

Primary mesenteric soft tissue sarcomas (STS) are rare and limited evidence is available to inform management. Surgical resection is challenging due to the proximity of vital structures and a need to preserve enteric function.

OBJECTIVES

To determine the overall survival (OS) and recurrence-free survival (RFS) for patients undergoing primary resection for mesenteric STS.

METHODS

The Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) is an intercontinental collaborative comprising specialist sarcoma centers. Data were collected retrospectively for all patients with mesenteric STS undergoing primary resection between 2000 and 2019.

RESULTS

Fifty-six cases from 15 institutions were included. The spectrum of pathology was similar to the retroperitoneum, although of a higher grade. R0/R1 resection was achieved in 87%. Median OS was 56 months. OS was significantly shorter in higher-grade tumors (p = .018) and extensive resection (p < .001). No significant association between OS and resection margin or tumor size was detected. Rates of local recurrence (LR) and distant metastases (DM) at 5 years were 60% and 41%, respectively. Liver metastases were common (60%), reflecting portal drainage of the mesentery.

CONCLUSION

Primary mesenteric sarcoma is rare, with a modest survival rate. LR and DM are frequent events. Liver metastases are common, highlighting the need for surveillance imaging.

Surgical management of a large retroperitoneal liposarcoma: A case study

The patient was a 45-year-old male who initially presented with a left hydrocele. During radiographic work-up, a 26 cm right retroperitoneal lipoma was incidentally discovered. Despite a recommendation for preoperative radiation therapy followed by surgery from the sarcoma multispecialty team, the patient opted for surgery alone, in the hopes of avoiding damage or loss of his right kidney. Following surgical excision of the 39 cm well-differentiated liposarcoma, with removal of the perinephric fat adjacent to the tumor thereby preserving the kidney, he was discharged home after two nights in the hospital. Follow-up imaging eight months later showed no recurrence.

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.