Retroperitoneal Soft Tissue Sarcoma Research Articles

The role of standard and novel radiotherapy approaches in management of retroperitoneal sarcomas

Primary non-metastatic retroperitoneal soft tissue sarcoma patients can be cured by radical surgery. However there remains a risk for patients to develop a local recurrence. To minimize this risk, patients with low grade liposarcomas might benefit from preoperative radiotherapy. This review summarizes all issues that should be considered for the irradiation of patients with retroperitoneal soft tissue sarcoma.

Closing the Distance Between Access and Expertise in Patients with Bone Sarcomas: Is There a Feasible Path Forward?: Commentary on an article by Tomohiro Fujiwara, MD, PhD, et al.: "Geographic Access to High-Volume Care Providers and Survival in Patients with Bone Sarcomas. Nationwide Patterns in the United States".

Commentary It is the dreaded news that we as oncology providers occasionally need to deliver to patients: “You have cancer.” Where should they turn for the best care? Is a local hospital enough, or is it beneficial to travel a farther distance to receive care at a more specialized institution? If that cancer happens to be a bone sarcoma, Fujiwara et al. have done a commendable job in providing further insight into this question in their current article. In recent years, an increasing amount of literature has been published with regard to improved outcomes at high-volume centers for many types of cancer, including non-orthopaedic tumors such as colorectal cancer1. As it relates to musculoskeletal malignancies, Abarca et al.2 showed, for extremity soft-tissue sarcomas, and Schmitz et al.3 showed, for retroperitoneal soft-tissue sarcomas, that high-volume facilities had a better overall survival rate and a lower rate of positive surgical margins when compared with lower-volume centers. Intuitively, I think, for those of us who treat bone sarcomas, it is understood that you need a multidisciplinary team in place with an abundance of experience and adherence to nationally accepted treatment guidelines. From a surgical standpoint, improved outcomes seem to correlate with repetition of treatment. However, what may not seem intuitive is that, when it comes to a rare type of tumor such as a bone sarcoma (only roughly 3,900 new cases will be diagnosed in the United States this year), the critical volume of experience needed to optimize outcomes is likely not available at every institution and may not even be available within every state. Given the limitation in new cases each year, centralized care for patients with bone sarcoma, or any other unique cancer, seems like an enticing system to help to improve survival. If a patient lives close to a high-volume center, then this treatment route is a no-brainer. However, for patients who may live farther away, choosing to travel a long distance to receive care at a high-volume center may mean lengthy time away from family and other support systems. If these individuals choose to not travel to a high-volume center, does this necessarily mean that they are negatively impacting their ability to be alive 5 years or even 10 years from now? I am not sure that we have a fully transparent answer to that question yet. As shown in the current article and previously reported by Malik et al.4, the overall survival for adult patients with bone sarcoma was not necessarily impacted by how far they had to travel to receive care but rather seeking care at an institution with extensive experience in treating this malignancy. In the virtual world in which we now live and with the increase in community-based hospital partnerships with high-volume National Cancer Institute (NCI) institutions, a patient now expects to receive the same level of expert care closer to home. What would be interesting to know (and is certainly beyond the scope of this article) is whether improved survival holds up at lower-volume centers that partner with higher-volume centers and adhere to nationally accepted treatment guidelines. I think that the landscape of musculoskeletal oncology would look quite different if we were to move toward a more centralized care pattern for patients with bone sarcoma. In his commentary article discussing high-volume centers compared with low-volume centers as they relate to pancreatic cancer, Carr5 brought up many relevant points that I think merit consideration for bone sarcomas. As Carr stated, it is simply not practical for patients with cancer, even rare or unique cancers, to be treated at only a handful of high-volume institutions. In addition, those patients who have complex reconstructive surgical procedures at places far away from where they live may require follow-up or operative care locally for complications that arise. A patient may travel once for a surgical procedure, but that willingness may wane over time for follow-up visits, leaving the onus on more local, less-experienced institutions to complete their course of care. Another point to consider is the need for increased oncology specialists at these high-volume centers to meet the potential increase in patient demand. In the end, we all want the best care for the patients whom we treat. The reality is that not every patient will travel, despite what the data show. The challenge then becomes how we can disseminate knowledge and experience to help to level the playing field so that adult patients can receive top-notch care for bone sarcoma closer to home. I am hopeful that future studies will help in clarifying this.

Radiomic Features From Diffusion-Weighted MRI of Retroperitoneal Soft-Tissue Sarcomas Are Repeatable and Exhibit Change After Radiotherapy.

BackgroundSize-based assessments are inaccurate indicators of tumor response in soft-tissue sarcoma (STS), motivating the requirement for new response imaging biomarkers for this rare and heterogeneous disease. In this study, we assess the test–retest repeatability of radiomic features from MR diffusion-weighted imaging (DWI) and derived maps of apparent diffusion coefficient (ADC) in retroperitoneal STS and compare baseline repeatability with changes in radiomic features following radiotherapy (RT).Materials and MethodsThirty patients with retroperitoneal STS received an MR examination prior to treatment, of whom 23/30 were investigated in our repeatability analysis having received repeat baseline examinations and 14/30 patients were investigated in our post-treatment analysis having received an MR examination after completing pre-operative RT. One hundred and seven radiomic features were extracted from the full manually delineated tumor region using PyRadiomics. Test–retest repeatability was assessed using an intraclass correlation coefficient (baseline ICC), and post-radiotherapy variance analysis (post-RT-IMS) was used to compare the change in radiomic feature value to baseline repeatability.ResultsFor the ADC maps and DWI images, 101 and 102 features demonstrated good baseline repeatability (baseline ICC > 0.85), respectively. Forty-three and 2 features demonstrated both good baseline repeatability and a high post-RT-IMS (>0.85), respectively. Pearson correlation between the baseline ICC and post-RT-IMS was weak (0.432 and 0.133, respectively).ConclusionsThe ADC-based radiomic analysis shows better test–retest repeatability compared with features derived from DWI images in STS, and some of these features are sensitive to post-treatment change. However, good repeatability at baseline does not imply sensitivity to post-treatment change.

Clinical Outcome of Patients with Pelvic and Retroperitoneal Bone and Soft Tissue Sarcoma: A Retrospective Multicenter Study in Japan.

Simple SummaryWe aimed to clarify the clinical outcomes of patients with pelvic and retroperitoneal bone and soft tissue sarcoma. The 3-year overall survival (OS), local control (LC) rate, and progression-free survival (PFS) were 71.7%, 79.1%, and 48.6%, respectively. The most influential poor prognostic factor for OS was distant metastasis, and for PFS, this was higher age (≥60 years). Larger primary tumor size (≥10 cm) was the only poor prognostic factor for LC. In the histological analysis, osteosarcoma showed significantly worse OS and PFS than other sarcomas in the pelvis and retroperitoneum.This study aimed to retrospectively analyze the clinical outcomes of patients with pelvic and retroperitoneal bone and soft tissue sarcoma (BSTS). Overall, 187 patients with BSTS in the pelvis and retroperitoneal region treated at 19 specialized sarcoma centers in Japan were included. The prognostic factors related to overall survival (OS), local control (LC), and progression-free survival (PFS) were evaluated. The 3-year OS and LC rates in the 187 patients were 71.7% and 79.1%, respectively. The 3-year PFS in 166 patients without any distant metastases at the time of primary tumor diagnosis was 48.6%. Osteosarcoma showed significantly worse OS and PFS than other sarcomas of the pelvis and retroperitoneum. In the univariate analyses, larger primary tumor size, soft tissue tumor, distant metastasis at the time of primary tumor diagnosis, P2 location, chemotherapy, and osteosarcoma were poor prognostic factors correlated with OS. Larger primary tumor size, higher age, soft tissue tumor, chemotherapy, and osteosarcoma were poor prognostic factors correlated with PFS in patients without any metastasis at the initial presentation. Larger primary tumor size was the only poor prognostic factor correlation with LC. This study has clarified the epidemiology and prognosis of patients with pelvic and retroperitoneal BSTS in Japan.

Intraabdominal and retroperitoneal soft-tissue sarcomas – Surgical treatment and outcomes

BackgroundIntraabdominal and retroperitoneal sarcomas (IaRS) are malignant connective tissue tumors. Surgical resection is often the only curative treatment. The primary objective was to report the mid-term outcomes following contemporary treatment protocols and identify prognostic factors. MethodsA retrospective review of consecutive patients (n = 107) with IaRS treated at single center from 2013 until 2018 was conducted. Histological diagnosis, tumor grade, perioperative complications, mortality, and long-time survival were registered and retrieved from patient records. Primary and recurrent tumors were analyzed separately. ResultsA total of 107 patients were identified. Median follow-up time was 3.5 years. Thirty-day mortality was 3.4% and 90-day mortality was 5.6% for all tumors. The major complication rate was 18%. The 5-year estimated survival for primary and recurrent tumors was 55.4% and 48.4%, respectively. Multifocal disease was evident in 32% of the patient cohort, and 58% of patients in the recurrent group. Multivariate analysis for survival revealed a hazard ratio (HR) of 3.1 (95% CI 1.68–8.41) for multifocality, HR 2.9 (95% CI 1.28–6.98) for Clavien-Dindo grade, HR 2.3 (95% CI 1.21–4.31) for tumor grades 2 or 3, and HR 1.002 (95% CI 1.001–1.004) for surgical margins. ConclusionsOur study found overall acceptable morbidity and mortality, and identified prognostic markers for overall survival. Recurrent tumors were not associated with worse survival. Multifocality is associated with a worse overall survival. The prognostic factors identified were; tumor grade, multifocality, intralesional margins and postoperative complications.

Prognostic Factors and Nomogram Construction for First Local Recurrent Retroperitoneal Sarcoma Following Surgical Resection: A Single Asian Cohort of 169 Cases.

ObjectiveThis study aimed to explore the prognostic factors for first local recurrent retroperitoneal soft tissue sarcoma (FLR-RPS) and construct predictive nomograms in the Asian population.MethodsIn a single Asian sarcoma center, data of patients with FLR-RPS were retrospectively analyzed from January 2011 to September 2020. We developed and internally validated prognostic factors determined by the Cox regression model, as well as nomograms for predicting recurrence-free survival (RFS) and overall survival (OS). The concordance index and calibration curve were used to determine the nomogram’s discriminative and predictive ability.ResultsWith 169 patients, the median follow-up duration was 48 months and the 5-year OS rate was 60.9% (95% confidence interval (CI), 51.9%–69.9%). OS was correlated with chemotherapy at the time of initial surgery and tumor grading. The 5-year cumulative local recurrence rate and distant metastasis rate were 75.9% (95% CI, 67.5%–84.3%) and 10.1% (95% CI, 4.2%–16.0%), respectively, and the length of the disease-free interval following the primary operation was associated with disease recurrence. The 6-year OS and cumulative recurrence rate after surgery in our cohort were comparable with those in the TARPSWG cohort, but the proportion of local recurrence was higher (80.4% vs. 59.0%), and distant metastasis was less common (10.1% vs. 14.6%). In this study, two nomogram prediction models were established, which could predict the 1-, 2-, and 5-year OS and RFS, and the concordance indices were 0.74 and 0.70, respectively. The calibration plots were excellent.ConclusionsFor the FLR-RPS patients, some can still achieve an ideal prognosis. The treatment of FLR-RPS in Asian populations can be aided by the predictive model established in this study.

The clinical significance of perioperative inflammatory index as a prognostic factor for patients with retroperitoneal soft tissue sarcoma.

The prognostic factors of retroperitoneal soft tissue sarcoma (STS) have been explored but not yet certain. This study evaluated the prognostic impact of various preoperative clinical parameters and inflammatory indices in primary STS, with a particular focus on the transition of inflammatory index before and after tumor resection in de-differentiated liposarcoma (DD-LPS). The clinical data of 113 patients with primary retroperitoneal STS receiving tumor resection were reviewed. Six variables (neutrophils, platelets, C-reactive protein (CRP), lymphocytes, albumin, and hemoglobin) in the blood samples were measured and nine inflammatory indices (neutrophil-lymphocyte ratio (NLR), CRP-lymphocyte ratio (CLR), platelet-lymphocyte ratio (PLR), neutrophil-albumin ratio (NAR), CRP-albumin ratio (CAR), platelet-albumin ratio (PAR), HALP (hemoglobin, albumin, lymphocyte and platelet), prognostic nutrition index (PNI), and modified Glasgow Prognostic Score (mGPS)) were calculated. The prognostic value of the indices was analyzed by univariate and multivariate analyses. Elevated NLR, CLR, PLR, NAR, CAR, PAR, and mGPS were associated with a worse overall survival (p = 0.0124, 0.0011, 0.049, 0.0047, 0.0085, 0.0332, and 0.0086, respectively) in univariate analysis. Multivariate analysis showed that elevated CLR and DD-LPS were associated with poor overall survival (p = 0.0267 and 0.0218, respectively) in all retroperitoneal STS. In DD-LPD, patients with preoperative high CLR, whose postoperative CLR was normalized, demonstrated a favorable survival rate similar to those with preoperative low CLR. Elevated CLR before surgery as well as DD-LPS were poor prognostic markers for overall survival in primary retroperitoneal STS. Perioperative CLR normalization may be related to a favorable prognosis in DD-LPS.

Undifferentiated pleomorphic sarcoma of the retroperitoneum mimicking a cortisol‐ and catecholamine‐secreting adrenal tumor

IntroductionRetroperitoneal tumors with endocrine abnormalities are suspected to be functional adrenal tumors. Retroperitoneal soft tissue sarcomas are rare tumors, without endocrine potential.Case presentationA 60‐year‐old male was referred for a 15 cm mass in the left suprarenal space. His plasma cortisol and catecholamine levels were elevated. He underwent open left adrenalectomy with radical nephrectomy and his endocrinological abnormalities were improved. Pathological findings suggested that it had originated from the retroperitoneal fat tissue, and a diagnosis of undifferentiated pleomorphic sarcoma was made based on the results of immunohistochemical analysis and fluorescence in situ hybridization. Interestingly, neither cortisol nor catecholamine was elevated when, 6 months after surgery, local recurrence developed.ConclusionThis is the first reported case of undifferentiated pleomorphic sarcoma accompanied by high levels of cortisol and catecholamine. We should keep in mind the possibility of tumors like retroperitoneal soft tissue sarcomas inducing endocrine abnormalities.

RETROPERITONEAL HIGH-GRADE SARCOMA IN A 76-YEARS-OLD MAN: Case Report.

Retroperitoneal soft tissue sarcomas (RPS) are rare tumours which account for approximately 12-15% of all soft tissue sarcomas with a mean incidence of 2.7 per million. RPS are frequently incidental ndings in the work-up for non-related symptoms or diseases and can grow to an extremely large size in the retroperitoneum before symptoms or signs of abdominal pain, back pain, bowel obstruction or a palpable abdominal mass develop. Surgical resection is the only hope for cure and is therefore the treatment of choice for localized disease. After tumour grade, the long-term survival following RPS resection is most dependent on the completeness of surgical resection. Other important factors are patient age, tumour subtype, tumour size, multifocality and centralized multidisciplinary management in a specialist sarcoma centre. The authors present a 76-year-old man presented with abdominal pain and a palpable mass in the right hemiabdomen. The abdomen CT scan revealed a voluminous retroperitoneal neoformation at the level of the right side, with axial diameters of 17x12 cm and cranio-caudal extension of 15 cm. He underwent an incisional abdominal biopsy of the neoformation with an eco-guided retroperitoneal surgical access. The histological diagnosis revealed the presence of a poorly differentiated malignant neoplasm, epithelioid-like, apparently mesenchymal, so the medical team decides to subject the patient to surgery to remove the neoformation in the right hemi-abdomen. The removed mass is then sent to the pathological anatomy and the histological diagnosis subsequently conrms the diagnosis of high-grade sarcoma with a well-differentiated liposarcoma component.

Low dose intraoperative radiation does positively influence recurrence after resection of retroperitoneal liposarcoma

Background: In retroperitoneal soft tissue sarcoma (STS) local recurrence (LR) rates are high. Application of intraoperative radiation therapy (IORT) has been frequently discussed. Still, the significance of IORT in multimodal treatment of retroperitoneal STS remains unclear.

Surgical implantation of CEB-01, novel drug delivery matrix, in patients with recurrent or locally advanced retroperitoneal soft tissue sarcoma (RPS)

Background: Surgical resection (SX) with gross and microscopically negative margins is the mainstay treatment for locally advanced RPS, however, resections are often incomplete, resulting in local recurrence. Local delivery of SN-38 by a biocompatible and biodegradable implant matrix (CEB-01) may control residual microscopic disease and reduce and/or delay local recurrence while decreasing systemic toxicity.

Retroperitoneal Soft-Tissue Sarcoma: Retrospective Study from a Cancer Hospital in Pakistan

Background: Retroperitoneal sarcomas (RPS) belong to a group of rare neoplasms, representing only 0.2% [1] of adult cancers and 1-2% [2] of all solid malignancies. The diagnosis of RPS is usually challenging and often delayed. Wide local excision with adequate margins, preferably outside the pseudo capsule remains the cornerstone of the treatment of non metastatic RPS. Most of the published work on RPS is from the west. There is a dearth of published data from the subcontinent, especially Pakistan.

Tsp2 Facilitates Tumor-associated Fibroblasts Formation and Promotes Tumor Progression in Retroperitoneal Liposarcoma.

Retroperitoneal liposarcoma (RLPS) is the most common subtype of retroperitoneal soft tissue sarcoma, characterized by a high recurrence rate and insensitivity to radiotherapy and chemotherapy. The function of tumor microenvironmental components, especially tumor-associated fibroblasts (TAFs), remains unclear in RLPS. The crosstalk between tumor cells and stromal cells should be clarified for therapy target discovery in RLPS. In this study, we demonstrated that TAFs from dedifferentiated liposarcoma (DDLPS) could attract LPS cells and promote their proliferation and migration. However, although α-SMA is positively expressed in RLPS, its expression does not indicate prognosis. By screening differentially expressed genes, performing Oncomine visualization, TCGA gene expression correlation analysis and qPCR verification, we determined that thrombospondin-2 (THBS2) gene expression was related to TAFs. The expression of Tsp2 protein, which was encoded by THBS2, was correlated with α-SMA expression, and it was an independent predictive factor for disease-free survival and recurrence-free survival in patients with RLPS. In vitro, Tsp2 facilitated the transformation of bone marrow-derived fibroblasts (BMFs) to TAFs and promoted the malignant biological behaviors of LPS cells by activating the MAPK/MEK/ERK pathway. Therefore, suppression of Tsp2 is expected to be a promising treatment method for RLPS patients.

Establishment and evaluation of retroperitoneal liposarcoma patient-derived xenograft models: an ideal model for preclinical study.

Retroperitoneal liposarcoma (RLPS) is one of the most common subtypes of retroperitoneal soft tissue sarcomas. It is characterized by poor sensitivity to radiotherapy and chemotherapy and a low success rate of complete surgical resection. However, there are few reliable preclinical RLPS models for target discovery and therapy research. In this study, we aimed to establish RLPS patient-derived xenograft (PDX) models that are useful for biological research and preclinical drug trials. A total of 56 freshly resected RLPS tissues were subcutaneously transplanted into non-obese diabetic-severe combined immune deficient (NOD-SCID) mice, with subsequent xenotransplantation into second-generation mice. The tumor engraftment rate of first generation PDXs was 44.64%, and higher success rates were obtained from implantations of dedifferentiated, myxous, pleomorphic, high-grade liposarcomas and those with retroperitoneal organ infiltration. The first- and second- generation PDX models preserved the histopathological morphology, gene mutation profiles and MDM2 amplification of the primary tissues. PDX models can also provide the benefit of retaining original tumor biology and microenvironment characteristics, such as abnormal adipose differentiation, elevated Ki67 levels, high microvessel density, cancer-associated fibroblast presence, and tumor-associated macrophage infiltration. Overall survival (OS) and disease-free survival (DFS) of patients with successful first-generation PDX engraftment were significantly poorer than those with failed engraftment. Treatment with MDM2 inhibitor RG7112 significantly suppressed tumor growth of DDLPS PDX in mice. In conclusion, we successfully established RLPS PDX models that were histologically, genetically, and molecularly consistent with the original tissues. These models might provide opportunities for advancing RLPS tumor biology research, facilitating the development of novel drugs, particularly those targeting MDM2 amplification, adipose differentiation process, angiogenesis, cancer-associated fibroblasts, and so on.

EJSO educational Special issue from the TARPSWG - Standard medical treatment and new options in retroperitoneal sarcoma

Retroperitoneal soft tissue sarcomas mainly consist histologically of liposarcomas and leiomyosarcomas. For the liposarcoma subgroup, the local relapse rate seems to determine patients' overall prognosis. In contrast, leiomyosarcoma patients are challenged by the development of metastatic disease; therefore, effective systemic therapies are the cornerstone to improve patients’ outcome. No doubt, the limited number of active regimens currently available makes the treatment of patients with locally advanced and/or metastatic disease challenging and results in the overall poor prognosis of this population. In this European Journal of Surgical Oncology Educational Special Issue from the Transatlantic Australasian RetroPeritoneal Sarcoma Working Group (TARPSWG), we aim to summarize state-of-the-art systemic treatments for patients with retroperitoneal sarcomas with a focus on the locally advanced and metastatic disease setting including conventional standard chemotherapies as well as new innovative treatment approaches in order to identify current unmet medical needs guiding the sarcoma community to initiate appropriate translational research projects and design innovative clinical trials.

Medicinal treatment of retroperitoneal soft tissue sarcomas

Retroperitoneal soft tissue sarcomas represent extreme challenges for interdisciplinary treatment teams. The sarcoma-specific experience of surgeons has the greatest impact on the survival of patients; however, too many patients still die despite optimal local treatment. The role of chemotherapy is undisputed only for patients with highly malignant bone sarcomas or rhabdomyosarcomas. For soft tissue sarcomas in adult patients, especially liposarcomas and leiomyosarcomas, the evidence situation is very unsatisfactory. This overview article discusses the complex data situation and controversial aspects that are relevant for current treatment decisions in interdisciplinary treatment teams.

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

Objective To compare the dosimetric difference between various modalities in the radiation treatment for renal retroperitoneal soft tissue sarcoma recurrence or metastasis (RRSTSRM) after radical nephrectomy, and assess the dosimetric advantage on protecting the organs at risk (OARs) in the carbon and proton radiotherapy for the patients with a single kidney. Methods A total of 12 patients with RRSTSRM who underwent radical nephrectomy were enrolled in this study. Carbon, proton, and photon radiotherapy were implemented for treatment planning. The prescription dose was fulfilled by simultaneously integrated boosting technique, with giving the planning target volume-1 (PTV-1) 51Gy (RBE) and planning target volume-2 (PTV-2) 60 Gy (RBE). Doses in the patient’s spinal cord, stomach, duodenum, bowel, colon, and contralateral kidney were evaluated. The normal tissue complication probability (NTCP) of the duodenum, bowel, colon, and contralateral kidney was derived under Lyman-Kutcher-Burman (LKB) estimation. Results In the carbon plans, the percentage volume of 95% prescription dose (V95%) covering PTV-1 (PTV-2) was 95.93% ± 3.42% (95.61% ± 4.26%). No significant dosimetric difference on the target was obtained between the four radiation modalities (P > .05). The percentage volume of receiving 40 Gy (RBE) [V40Gy (RBE)] in the duodenum could be reduced from 12.94% ± 15.99% in the IMRT plans to 6.36% ± 8.79% (8.44% ± 12.35%) in the carbon (proton) plans (P < .05). The V40Gy (RBE) in the bowel could be reduced from 13.48% ± 13.12% in the IMRT plans to 7.04% ± 9.32% (7.34% ± 9.89%) in the carbon (proton) plans (P < .05). The mean value of NTCP for the duodenum was 0.43 ± 0.47 (0.45 ± 0.48) by using carbon (proton) radiation. The value was 0.05 (0.03) lower than the IMRT plans on average, with a reduction of 0.20 (0.13) for the patients with lesions <5 mm away from the duodenum. The mean doses of the contralateral kidney were 0.28 ± 0.37 Gy (RBE) [0.28 ± 0.40 Gy (RBE)] in the IMCT (IMPT) plans, which was 92.43% (92.43%) lower than the value in the IMRT plans respectively (P < .05). Conclusion Compared to the conventional radiation techniques, particle radiotherapy of carbon and proton could significantly spare more OARs in the treatment for RRSTSRM after radical nephrectomy. Patients, especially those whose residuals are close to the duodenum would potentially benefit from the particle radiation therapy for RRSTSRM on the decrease in radiation-related side-effect.

ASO Visual Abstract: National Trends in Treatment for Retroperitoneal Soft Tissue Sarcoma—A Modern Appraisal of Variability in Therapeutic Strategies

ASO Visual Abstract: National Trends in Treatment for Retroperitoneal Soft Tissue Sarcoma—A Modern Appraisal of Variability in Therapeutic Strategies

Incidence, Treatment and Outcome of Patients with Retroperitoneal Soft-Tissue Sarcoma in Switzerland 2005\u20132015: A Population-Based Analysis

BackgroundReports on the epidemiology and mortality of retroperitoneal soft tissue sarcoma (RSTS) in Switzerland are scarce. This study investigates the incidence and outcomes of surgically treated RSTS inpatients in Switzerland depending on the hospital type and size.MethodsData from the Swiss Federal Statistical Office were used to conduct a retrospective analysis of all RSTS inpatients and hospitalizations in Switzerland between 2005 and 2015. RSTS was identified by the code C48.x of the International Classification of Diseases (ICD-10). Sarcoma centers were identified by the annual total number of sarcoma patients (> 50 patients/year). The analysis of yearly incidence, age distribution as well as in-hospital complication and mortality was performed for non- and surgical-treated patients. A centralization of treating sarcoma patients was analyzed by the trend of hospitalizations in sarcoma centers and high-volume hospitals.ResultsDuring 2005–2015, 2.801 hospitalizations (1651 patients) were admitted to Swiss hospitals with the primary diagnosis of a RSTS. The yearly number of RSTS patients and the incidence (1.91/100.000) stayed constant within these 11 years. There were five sarcoma centers. We saw a clear trend of RSTS patients being treated (especially surgically) in centers over the 11 years. The complication rate of surgical-treated patients was higher in sarcoma centers (55% vs. 40%), though the overall mortality rate was lower (3.2% vs. 9.1%).ConclusionCentralization of RSTS treatment to certified sarcoma centers leads to a lower overall mortality rate and thus is highly recommended.

ASO Author Reflections: Retroperitoneal Soft Tissue Sarcoma: A Call for Collaboration and Scientific Inquiry.

ASO Author Reflections: Retroperitoneal Soft Tissue Sarcoma: A Call for Collaboration and Scientific Inquiry.