Adjuvant therapy for retroperitoneal sarcoma: a meta-analysis

Neoadjuvant or Adjuvant Chemotherapy in Soft-Tissue Sarcoma?

PURPOSE OF REVIEW

The review compares the effectiveness of neoadjuvant(pre-operative, NAC) and adjuvant(post-operative, AC) in Soft Tissue Sarcomas as this topic is controvesial and multiple new studies have been over the years.

RECENT FINDINGS

Sarculator and other nomograms assess patients with a predicted 10-year OS below 60% who will benefit from perioperative chemotherapy. Further research supports perioperative chemotherapy's role. European guidelines do not recommend anthracycline and ifosfamide (AI) perioperative chemotherapy as a standard treatment for STS of the extremities and trunk. However, some studies show that AI chemotherapy can improve recurrence-free survival (RFS). The EORTC 62,771 trial found that the CYVADIC regimen (doxorubicin, dacarbazine, cyclophosphamide, vincristine) reduced RFS without affecting OS. Meanwhile, the EORTC 62,931 trial showed no effect of AI chemotherapy on RFS or OS, but a pooled analysis suggested an OS benefit for patients with R1 (microscopically positive) resections. The AI regimen shows further support from Sarculator-based data, with EORTC 62,931 analysis indicating an improvement in disease-free survival and OS in patients with low expected OS. Similar outcomes were seen in the ISG-STS 1001 study. Recently, PERSARC analysis revealed that AI chemotherapy significantly improves OS in high-grade STS patients with a low 5-year OS prediction (< 33%). NAC improves the chances of complete tumour removal, especially in large, high-grade tumours. It often reduces the need for more aggressive surgeries by shrinking tumours before surgery, leading to higher rates of successful resections with clear margins (R0). Sarculator and other nomograms assess patients with a predicted 10-year OS below 60% who will benefit from perioperative chemotherapy. Further research supports perioperative chemotherapy's role.

Giant retroperitoneal liposarcoma with colonic infiltration as a cause of gastrointestinal bleeding: Case report and literature review

INTRODUCTION

Retroperitoneal liposarcomas are rare malignant tumors that often present asymptomatically until advanced stages. Giant liposarcomas exceeding 30 cm are particularly uncommon, and colonic infiltration causing gastrointestinal bleeding is extremely rare, with only a few cases documented in the literature.

CASE PRESENTATION

A 78-year-old female presented with hematochezia, constipation, and diffuse abdominal pain. Imaging revealed a large left para-aortic retroperitoneal mass compressing the colon. Colonoscopy showed colonic mucosal atrophy without active bleeding. Surgical exploration via midline laparotomy identified a bilobulated 89 × 35 × 40 cm retroperitoneal mass, infiltrating the left colon and compromising adjacent structures. En bloc resection, including hemicolectomy and left salpingo-oophorectomy, was performed. Histopathology confirmed a dedifferentiated liposarcoma with well-differentiated areas and colonic invasion reaching the muscularis propria. Margins were positive (R1). The patient recovered well postoperatively and experienced a single episode of intestinal obstruction at 6 months, resolved medically.

DISCUSSION

Retroperitoneal liposarcomas typically exhibit compressive behavior rather than invasion. However, dedifferentiation is associated with aggressive features, including local invasion and higher recurrence rates. Colonic infiltration by giant liposarcomas is exceedingly rare, with only three additional cases reported. Mechanisms of bleeding include mucosal ischemia, compression, or direct histological infiltration, as observed in this case.

CONCLUSION

The relationship between gastrointestinal bleeding and colonic infiltration in retroperitoneal liposarcomas may reflect the association between tumor dedifferentiation and invasive behavior. This underscores the importance of curative-intent surgical management as the primary therapeutic strategy, despite the challenge posed by the proximity to critical neurovascular structures.

A systematic review of the role of chemotherapy in retroperitoneal sarcoma by the Australia and New Zealand sarcoma association clinical practice guidelines working party

BACKGROUND

In primary localised resectable retroperitoneal sarcoma (RPS), loco-regional and distant relapse occur frequently despite optimal surgical management. The role of chemotherapy in improving outcomes is unclear.

METHODS

A systematic review was conducted, using the population, intervention, comparison outcome (PICO) model, to evaluate whether neoadjuvant or adjuvant chemotherapy improve outcomes in adults with primary localised resectable RPS. Medline, Embase and Cochrane Central were queried for publications from 1946 to June 2022 that evaluated recurrence free survival, overall survival, and post operative complications. Each study was screened by two independent reviewers for suitability. A qualitative synthesis of the results was performed.

RESULTS

Twenty three studies were identified; one meta-analysis of retrospective studies and 22 retrospective studies including three with propensity matched cohorts. Most studies did not analyse outcomes by histology, detail treatment regimens, provide baseline characteristics or selection criteria for those receiving chemotherapy. Evidence of selection bias was illustrated in several studies. Newcastle-Ottawa quality of retrospective cohort studies was good for 12 studies and poor for 10 studies. All studies were assessed as Level III-2 evidence by the Australian NHMRC hierarchy. Overall, the addition of neoadjuvant or adjuvant chemotherapy to surgery was not associated with improvement in local recurrence, metastasis free survival, disease free survival or overall survival in primary localised resectable RPS. There is some evidence of an association of chemotherapy with worse overall survival. One single centre study showed that neoadjuvant chemotherapy was not associated with increased post operative complications compared to surgery alone in primary localised resectable RPS.

CONCLUSIONS

There is currently no evidence that demonstrates the addition of chemotherapy to surgery improves outcomes in adult patients with primary localised resectable RPS. Available evidence is limited by its retrospective nature and high likelihood of selection bias with chemotherapy generally administered to patients at higher risk of recurrence and many patients not receiving care in high volume sarcoma centres. Randomised trials are required to conclusively determine the role of chemotherapy in primary localised resectable RPS.

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.

Radiation Therapy for Retroperitoneal Sarcomas: A Strass-Ful Situation

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

Longitudinal and time-to-event modeling for prognostic implications of radical surgery in retroperitoneal sarcoma

Retroperitoneal sarcoma (RPS) is a rare malignancy which can be difficult to manage due to the variety of clinical behaviors. In this study, we aimed to develop a parametric modeling framework to quantify the relationship between postoperative dynamics of several biomarkers and overall/progression-free survival of RPS. One hundred seventy-four patients with RPS who received surgical resection with curative intent at the Peking University Cancer Hospital Sarcoma Center were retrospectively included. Potential prognostic factors were preliminarily identified. Longitudinal analyses of body mass index (BMI), serum total protein (TP), and white blood cells (WBCs) were performed using nonlinear mixed effects models. The impacts of time-varying and time-invariant predictors on survival were investigated by parametric time-to-event (TTE) models. The majority of patients experienced decline in BMI, recovery of TP, as well as transient elevation in WBC counts after surgery, which significantly correlated with survival. An indirect-response model incorporating surgery effect described the fluctuation in percentage BMI. The recovery of TP was captured by a modified Gompertz model, and a semimechanistic model was selected for WBCs. TTE models estimated that the daily cumulative average of predicted BMI and WBC, the seventh-day TP, as well as certain baseline variables, were significant predictors of survival. Model-based simulations were performed to examine the clinical significance of prognostic factors. The current work quantified the individual trajectories of prognostic biomarkers in response to surgery and predicted clinical outcomes, which would constitute an additional strategy for disease monitoring and intervention in postoperative RPS.

The Janus-faced role of TRPM2-S in retroperitoneal liposarcoma via increasing ROS levels

BACKGROUND

Retroperitoneal liposarcoma (RPLS) is a specific soft tissue sarcoma with a high recurrence rate. The short isoform of transient receptor potential cation channel subfamily M member 2 (TRPM2-S) plays an important role in the regulation of reactive oxygen species (ROS). However, the association between TRPM2-S and RPLS and its underlying mechanisms remains unclear.

METHODS

The expression of both TRPM2-S and TRPM2-L in RPLS tissues was verified by kimmunohistochemistry (IHC). The regulation on Ca2+ influx by TRPM2-S was evaluated by Fluo-4 AM staining. The effect of TRPM2-S on cell proliferation and apoptosis was tested by 5-Ethynyl-2'-deoxyuridine (EdU) staining and Flow cytometry respectively. The level of cellular ROS was assessed by the DCFH-DA probe. Different concentrations of H2O2 were used to provide oxidative stress on RPLS cells. The underlying mechanisms were further explored by Western blotting.

RESULTS

The IHC assays showed that TRPM2-S, but not TRPM2-L, was prognostic in RPLS. Low TRPM2-S level was associated with poor disease-free survival (DFS). Calcium influx signal intensity was significantly decreased under TRPM2-S overexpression, which resulted in a decrease in the levels of FOXO3a and PTEN. Correspondingly, the levels of pERK, pAKT, pP65, pGSK-3β, Bcl-2, and β-catenin were upregulated, and cellular ROS was gently increased under TRPM2-S overexpression. Moreover, TRPM2-S slightly promoted cell proliferation and inhibited apoptosis of RPLS cell lines under normoxia, but largely increased apoptosis rates under oxidative stress. The cleaved caspase3 was significantly upregulated by TRPM2-S overexpression under oxidative stress. N-Acetyl-L-cysteine (NAC), a small molecule antioxidant, could largely rescue RPLS cells from the apoptosis induced by H2O2.

CONCLUSION

TRPM2-S exerts Janus-faced effects in RPLS by increasing the ROS levels via inhibition on FOXO3a, which promotes cell proliferation under normoxia but induces apoptosis under oxidative stress. Video abstract.

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.