Soft-tissue sarcoma in adults: An update on the current state of histiotype-specific management in an era of personalized medicine.

Soft-tissue sarcomas (STS) are rare tumors that account for 1% of all adult malignancies, with over 100 different histologic subtypes occurring predominately in the trunk, extremity, and retroperitoneum. This low incidence is further complicated by their variable presentation, behavior, and long-term outcomes, which emphasize the importance of centralized care in specialized centers with a multidisciplinary team approach. In the last decade, there has been an effort to improve the quality of care for patients with STS based on anatomic site and histology, and multiple ongoing clinical trials are focusing on tailoring therapy to histologic subtype. This report summarizes the latest evidence guiding the histiotype-specific management of extremity/truncal and retroperitoneal STS with regard to surgery, radiation, and chemotherapy.

New Sarculator Prognostic Nomograms for Patients With Primary Retroperitoneal Sarcoma: Case Volume Does Matter.

OBJECTIVE: To update the current Sarculator retroperitoneal sarcoma (RPS) prognostic nomograms considering the improvement in patient prognosis and the case volume effect. BACKGROUND: Survival of patients with primary RPS has been increasing over time, and the volume-outcome relationship has been well recognized. Nevertheless, the specific impact on prognostic nomograms is unknown. METHODS: All consecutive adult patients with primary localized RPS treated at 8 European and North American sarcoma reference centers between 2010 and 2017 were included. Patients were divided into 2 groups: high-volume centers (HVC, ≥13 cases/year) and low-volume centers (LVC, <13 cases/year). Primary end points were overall survival (OS) and disease-free survival (DFS). Multivariable analyses for OS and DFS were performed. The nomograms were updated by recalibration. Nomograms performance was assessed in terms of discrimination (Harrell C index) and calibration (calibration plot). RESULTS: The HVC and LVC groups comprised 857 and 244 patients, respectively. The median annual primary RPS case volume (interquartile range) was 24.0 in HVC (15.0-41.3) and 9.0 in LVC (1.8-10.3). Five-year OS was 71.4% (95% CI: 68.3%-74.7%) in the HVC cohort and 63.3% (56.8%-70.5%) in the LVC cohort ( P =0.012). Case volume was associated with both OS (LVC vs. HVC hazard ratio 1.40, 95% CI: 1.08-1.82, P =0.011) and DFS (hazard ratio 1.93, 95% CI: 1.57-2.37, P <0.001) at multivariable analyses. When applied to the study cohorts, the Sarculator nomograms showed good discrimination (Harrell C index between 0.68 and 0.73). The recalibrated nomograms showed good calibration in the HVC group, whereas the original nomograms showed good calibration in the LVC group. CONCLUSIONS: New nomograms for patients with primary RPS treated with surgery at high-volume versus low-volume sarcoma reference centers are available in the Sarculator app.

Sarculator: how to improve further prognostication of all sarcomas.

PURPOSE OF REVIEW: Prognostication of soft tissue sarcomas is challenging due to the diversity of prognostic factors, compounded by the rarity of these tumors. Nomograms are useful predictive tools that assess multiple variables simultaneously, providing estimates of individual likelihoods of specific outcomes at defined time points. Although these models show promising predictive ability, their use underscores the need for further methodological refinement to address gaps in prognosis accuracy. RECENT FINDINGS: Ongoing efforts focus on improving prognostic tools by either enhancing existing models based on established parameters or integrating novel prognostic markers, such as radiomics, genomic, proteomic, and immunologic factors. Artificial intelligence is a new field that is starting to be explored, as it has the capacity to combine and analyze vast and intricate amounts of relevant data, ranging from multiomics information to real-time patient outcomes. SUMMARY: The integration of these innovative markers and methods could enhance the prognostic ability of nomograms such as Sarculator and ultimately enable more accurate and individualized healthcare. Currently, clinical variables continue to be the most significant and effective factors in terms of predicting outcomes in patients with STS. This review firstly introduces the rationale for developing and employing nomograms such as Sarculator, secondly, reflects on some of the latest and ongoing methodological refinements, and provides future perspectives in the field of prognostication of sarcomas.

A CT-based radiomics classification model for the prediction of histological type and tumour grade in retroperitoneal sarcoma (RADSARC-R): a retrospective multicohort analysis.

BACKGROUND: Retroperitoneal sarcomas are tumours with a poor prognosis. Upfront characterisation of the tumour is difficult, and under-grading is common. Radiomics has the potential to non-invasively characterise the so-called radiological phenotype of tumours. We aimed to develop and independently validate a CT-based radiomics classification model for the prediction of histological type and grade in retroperitoneal leiomyosarcoma and liposarcoma. METHODS: A retrospective discovery cohort was collated at our centre (Royal Marsden Hospital, London, UK) and an independent validation cohort comprising patients recruited in the phase 3 STRASS study of neoadjuvant radiotherapy in retroperitoneal sarcoma. Patients aged older than 18 years with confirmed primary leiomyosarcoma or liposarcoma proceeding to surgical resection with available contrast-enhanced CT scans were included. Using the discovery dataset, a CT-based radiomics workflow was developed, including manual delineation, sub-segmentation, feature extraction, and predictive model building. Separate probabilistic classifiers for the prediction of histological type and low versus intermediate or high grade tumour types were built and tested. Independent validation was then performed. The primary objective of the study was to develop radiomic classification models for the prediction of retroperitoneal leiomyosarcoma and liposarcoma type and histological grade. FINDINGS: 170 patients recruited between Oct 30, 2016, and Dec 23, 2020, were eligible in the discovery cohort and 89 patients recruited between Jan 18, 2012, and April 10, 2017, were eligible in the validation cohort. In the discovery cohort, the median age was 63 years (range 27-89), with 83 (49%) female and 87 (51%) male patients. In the validation cohort, median age was 59 years (range 33-77), with 46 (52%) female and 43 (48%) male patients. The highest performing model for the prediction of histological type had an area under the receiver operator curve (AUROC) of 0·928 on validation, based on a feature set of radiomics and approximate radiomic volume fraction. The highest performing model for the prediction of histological grade had an AUROC of 0·882 on validation, based on a radiomics feature set. INTERPRETATION: Our validated radiomics model can predict the histological type and grade of retroperitoneal sarcomas with excellent performance. This could have important implications for improving diagnosis and risk stratification in retroperitoneal sarcomas. FUNDING: Wellcome Trust, European Organisation for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group, the National Institutes for Health, and the National Institute for Health and Care Research Biomedical Research Centre at The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research.

Pathological and radiological response following neoadjuvant treatments in primary localized resectable myxofibrosarcoma and undifferentiated pleomorphic sarcoma of the extremities and trunk wall.

BACKGROUND: To explore the correlation between pathological and radiological response to preoperative treatments and outcome in surgically treated patients with myxofibrosarcoma (MFS) and undifferentiated pleomorphic sarcoma (UPS). METHODS: All consecutive patients with primary localized MFS and UPS of the extremities and trunk wall surgically treated with curative intent at our center (2005-2021) were included. Clinical data including residual visible tumor (VT%) on surgical specimen and Response Evaluation Criteria in Solid Tumor (RECIST) were retrieved. Kaplan-Meier curves for overall survival and disease-free survival, and cumulative incidence of local relapse and distant metastasis were estimated in a competing risk framework according to RECIST and VT%, overall and by treatment group. Cox and Fine and Gray multivariable models were performed. RESULTS: Of 693 patients affected by primary MFS and UPS, 233 (66 MFS and 167 UPS) were treated by neoadjuvant chemotherapy (naChT), radiotherapy (naRT), or both (naChT-RT). VT% was ≤5% in 13/46 (28.2%), 24/99 (24.2%), and 40/88 (45.4%) patients, respectively. There were 11/46 (29.7%), 22/99 (22.7%), and 23/88 (26.1%) RECIST partial responses and 18/46 (48.6%), 59/99 (60.8%), and 60/88 (68.2%) RECIST stable disease, respectively. In naChT, a trend for a better survival was observed when VT% ≤5% (p = .09), whereas RECIST partial responses and stable disease had the same outcome. VT% was not associated with outcome in naRT or naChT-RT, whereas RECIST response was. CONCLUSION: In primary localized MFS and UPS treated with neoadjuvant therapies, VT% seems more relevant than size reduction after naChT, whereas the opposite is true when naRT is administered alone or concurrent to ChT.

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.

Next questions in the management of retroperitoneal sarcoma.

PURPOSE OF REVIEW: Retroperitoneal soft-tissue sarcomas (RPS) are a group of rare, histologically distinct tumours with variable recurrence patterns depending on histological type. This review will discuss the growing body of evidence supporting histology-specific, multidisciplinary management and highlight areas of future research for patients with RPS. RECENT FINDINGS: Histology-tailored surgery is the cornerstone of management in patients with localized RPS. Further efforts to develop resectability criteria and identify patients who will benefit from neoadjuvant treatment strategies will help standardize the treatment of patients with localized RPS. Surgery for local recurrence is well tolerated in selected patients and re-iterative surgery in liposarcoma (LPS) may be beneficial at the time of local recurrence. The management of advanced RPS holds promise with several trials currently investigating systemic treatment beyond conventional chemotherapy. SUMMARY: The management of RPS has made significant progress over the past decade owing to international collaboration. Ongoing efforts to identify patients who will derive the most benefit from all treatment strategies will continue to advance the field of RPS.

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

BACKGROUND: Surgery is the treatment mainstay in retroperitoneal sarcoma (RPS), a frontline comprehensive approach based on tumor removal en bloc with adherent viscera is mandatory especially for liposarcoma, where the normal retroperitoneal fat is undistinguishable from the well-differentiated tumor component.1-5 In this video, a reproducible and standardized six-stage approach to a primary right retroperitoneal liposarcoma is presented. PATIENT AND METHODS: A 23-cm right retroperitoneal, well-differentiated liposarcoma was diagnosed in a 68-year-old female patient in December 2021. The tumor involved the right kidney and adrenal gland; displacing anteriorly the right colon, the duodenum, and the pancreatic head; and invading part of the ipsilateral psoas muscle. After the publication of the STRASS trial and STREXIT results,6,7 neoadjuvant radiotherapy was delivered to a total dose of 50.4 Gy in 28 fractions with stable disease. Virtual 3D reconstruction of regional anatomy by Visible Patient was performed preoperatively. RESULTS: The patient underwent right retroperitoneal mass resection en bloc with ipsilateral kidney and adrenal gland, colon, psoas muscle, and portion of ipsilateral diaphragm. Of note, the resection of the psoas muscle was performed to obtain a safe posterior margin and accomplish a better clearance of fat of the posterior abdominal wall. This can be limited to the psoas fascia whenever the tumor is not adherent to it. A six-stage approach was performed, as described in the supplementary video file. CONCLUSIONS: RPS resection is complex and requires a broad range of surgical expertise. A staged approach that can be followed in virtually all cases is highly recommended to achieve an optimal tumor resection.

Organ Infiltration and Patient Risk After Multivisceral Surgery for Primary Retroperitoneal Liposarcomas.

BACKGROUND: The extent of histological organ involvement (HOI) to organs and structures of a retroperitoneal liposarcoma may have prognostic implications. This study investigated incidence, characteristics, and risk association of HOI in these patients. PATIENTS AND METHODS: Data of patients who underwent multivisceral resection for primary liposarcoma (2009-2014) were retrospectively analyzed. HOI was the variable of interest and was classified into four degrees: absent (HOI-0), perivisceral (HOI-1), initial (HOI-2), and advanced (HOI-3). Primary endpoint was overall survival (OS). Secondary endpoint was disease-free survival (DFS). The prognostic value of HOI was adjusted for preoperative treatment and the Sarculator nomogram score. RESULTS: A total of 109 patients were included. HOI-0, HOI-1, HOI-2, and HOI-3 were detected in 9 (8.3%), 11 (10.1%), 43 (39.4%), and 46 (42.2%) patients. Median follow-up was 8.4 years [interquartile range (IQR) 7.2-9.6 years]. There were 68 recurrences and 50 patient deaths observed, resulting in a 10-year OS and DFS of 51.1% [95% confidence interval (CI) 41.9-62.1%] and 34.1% (95% CI 25.2-46.1%), respectively. Clinically relevant HOIs (HOI-2 and HOI-3) were found in 35/45 (77.8%) and 54/64 (84.4%) cases of well- and de-differentiated liposarcomas, respectively. On multivariable survival analysis, patients with HOI-3 had significantly shorter OS (HOI-3 vs HOI-0/HOI-1 HR 2.92; p = 0.012) and DFS (HOI-3 vs HOI-0/HOI-1 HR 2.23; p = 0.045), independently of the nomogram score (OS: HR 2.93; p < 0.001; DFS: HR 1.78; p = 0.003). CONCLUSIONS: Initial and advanced HOIs are frequently detected in both well-differentiated and de-differentiated liposarcomas, supporting that multivisceral resection may be needed. HOI stratifies the risk of patients with primary retroperitoneal liposarcoma.

Datasets for reporting of soft-tissue sarcoma: recommendations from the International Collaboration on Cancer Reporting (ICCR).

AIMS: Soft-tissue tumours are rare and both accurate diagnosis and proper treatment represent a global challenge. Current treatment guidelines also recommend review by specialised pathologists. Here we report on international consensus-based datasets for the pathology reporting of biopsy and resection specimens of soft-tissue sarcomas. The datasets were produced under the auspices of the International Collaboration on Cancer Reporting (ICCR), a global alliance of international pathology and cancer organisations. METHODS AND RESULTS: According to the ICCR's guidelines for dataset development, an international expert panel consisting of pathologists, a surgical oncologist, and a medical oncologist produced a set of core and noncore data items for biopsy and resection specimens based on a critical review and discussion of current evidence. All professionals involved were subspecialised soft-tissue sarcoma experts and affiliated with tertiary referral centres. Commentary was provided for each data item to explain the rationale for selecting it as a core or noncore element, its clinical relevance, and to highlight potential areas of disagreement or lack of evidence, in which case a consensus position was formulated. Following international public consultation, the documents were finalised and ratified, and the datasets, which included a synoptic reporting guide, were published on the ICCR website. CONCLUSION: These first international datasets for soft-tissue sarcomas are aimed to promote high-quality, standardised pathology reporting. Their adoption will improve consistency of reporting, facilitate multidisciplinary communication, and enhance comparability of data, all of which will help to improve patient's management.

First-line chemotherapy in advanced intra-abdominal well-differentiated/dedifferentiated liposarcoma: An EORTC Soft Tissue and Bone Sarcoma Group retrospective analysis.

BACKGROUND: No prospective trial with anthracycline-based chemotherapy has individually assessed response in a well-differentiated (WD)/dedifferentiated (DD) liposarcoma patient cohort. We conducted a retrospective analysis of first-line chemotherapy in liposarcoma of intra-abdominal origin (IA-LPS) in patients who had entered the European Organisation for Research and Treatment of Cancer (EORTC)/Soft Tissue and Bone Sarcoma Group (STBSG) trials. METHODS: We searched for all adult patients treated with first-line chemotherapy for advanced IA-LPS in the EORTC STBSG phase 2 and 3 trials from 1978. Treatment was aggregated into 5 groups: anthracycline alone, ifosfamide alone, doxorubicin plus ifosfamide (D+IFO), doxorubicin/cyclophosphamide/vincristine/dacarbazine, and "other" (brostallicin, trabectedin). Response was assessed prospectively by Response Evaluation Criteria in Solid Tumors or World Health Organization criteria. Progression-free survival (PFS) and overall survival (OS) were computed by Kaplan-Meier method. RESULTS: A total of 109 patients with IA-LPS from 13 trials were identified (104 evaluable for response). Overall, there were 10/109 (9.2%) responders: 3/48 (6.3%) in the anthracycline alone group, 2/15 (13%) in the ifosfamide alone group, and 4/18 (22%) in the D+IFO group. At the 10-month median follow-up (interquartile range, 6-24), the median OS was 19 months (95% CI, 15-21) and median PFS 4 months (95% CI, 3-6). D+IFO achieved a not statistically significant longer median PFS (12 months) and median OS (31 months) than observed with other regimens. Univariate/multivariate analysis did not identify prognostic factors. CONCLUSIONS: Cytotoxic chemotherapy, in particular anthracycline alone, had marginal activity in advanced IA-LPS. Ifosfamide-containing regimens showed higher activity, although it was not statistically significant and in a small number of cases, with the combination of doxorubicin and ifosfamide appearing to be the more active regimen available in fit patients. This series provides a benchmark for future trials on new drugs in WD/DD liposarcoma.

Critical impact of radiotherapy protocol compliance and quality in the treatment of retroperitoneal sarcomas: Results from the EORTC 62092-22092 STRASS trial.

BACKGROUND: The European Organization for Research and Treatment of Cancer 22092-62092 STRASS trial failed to demonstrate the superiority of neoadjuvant radiotherapy (RT) over surgery alone in patients with retroperitoneal sarcoma. Therefore, an RT quality-assurance program was added to the study protocol to detect and correct RT deviations. The authors report results from the trial RT quality-assurance program and its potential effect on patient outcomes. METHODS: To evaluate the effect of RT compliance on survival outcomes, a composite end point was created. It combined the information related to planning target volume coverage, target delineation, total dose received, and overall treatment time into 2 groups: non-RT-compliant (NRC) for patients who had unacceptable deviation(s) in any of the previous categories and RT-compliant (RC) otherwise. Abdominal recurrence-free survival (ARFS) and overall survival were compared between the 2 groups using a Cox proportional hazard model adjusted for known prognostic factors. RESULTS: Thirty-six of 125 patients (28.8%) were classified as NRC, and the remaining 89 patients (71.2%) were classified as RC. The 3-year ARFS rate was 66.8% (95% confidence interval [CI], 55.8%-75.7%) and 49.8% (95% CI, 32.7%-64.8%) for the RC and NRC groups, respectively (adjusted hazard ratio, 2.32; 95% CI, 1.25-4.32; P = .008). Local recurrence after macroscopic complete resection occurred in 13 of 89 patients (14.6%) versus 2 of 36 patients (5.6%) in the RC and NRC groups, respectively. CONCLUSIONS: The current analysis suggests a significant benefit in terms of ARFS in favor of the RC group. This association did not translate into less local relapses after complete resection in the RC group. Multidisciplinary collaboration and review of cases are critical to avoid geographic misses, especially for rare tumors like retroperitoneal sarcoma.

Neoadjuvant chemotherapy in high-risk soft tissue sarcomas: A Sarculator-based risk stratification analysis of the ISG-STS 1001 randomized trial.

BACKGROUND: The value of neoadjuvant chemotherapy in soft tissue sarcoma (STS) is not completely understood. This study investigated the benefit of neoadjuvant chemotherapy according to prognostic stratification based on the Sarculator nomogram for STS. METHODS: This study analyzed data from ISG-STS 1001, a randomized study that tested 3 cycles of neoadjuvant anthracycline plus ifosfamide (AI) or histology-tailored (HT) chemotherapy in adult patients with STS. The 10-year predicted overall survival (pr-OS) was estimated with the Sarculator and was stratified into higher (10-year pr-OS < 60%) and lower risk subgroups (10-year pr-OS ≥ 60%). RESULTS: The median pr-OS was 0.63 (interquartile range [IQR], 0.51-0.72) for the entire study population, 0.62 (IQR, 0.51-0.70) for the AI arm, and 0.64 (IQR, 0.51-0.73) for the HT arm. Three- and 5-year overall survival (OS) were 0.86 (95% confidence interval [CI], 0.82-0.93) and 0.81 (95% CI, 0.71-0.86) in lower risk patients and 0.69 (95% CI, 0.70-0.85) and 0.59 (95% CI, 0.51-0.72) in the higher risk patients (log-rank test, P = .004). In higher risk patients, the 3- and 5-year Sarculator-predicted and study-observed OS rates were 0.68 and 0.58, respectively, and 0.85 and 0.66, respectively, in the AI arm (P = .04); the corresponding figures in the HT arm were 0.69 and 0.60, respectively, and 0.69 and 0.55, respectively (P > .99). In lower risk patients, the 3- and 5-year Sarculator-predicted and study-observed OS rates were 0.85 and 0.80, respectively, and 0.89 and 0.82, respectively, in the AI arm (P = .507); the corresponding figures in the HT arm were 0.87 and 0.81, respectively, and 0.86 and 0.74, respectively (P = .105). CONCLUSIONS: High-risk patients treated with AI performed better than predicted, and this adds to the evidence for the efficacy of neoadjuvant AI in STS. LAY SUMMARY: People affected by soft tissue sarcomas of the extremities and trunk wall are at some risk of developing metastasis after surgery. Preoperative or postoperative chemotherapy has been tested in clinical trials to reduce the chances of distant metastasis. However, study findings have not been conclusive. This study stratified the risk of metastasis for people affected by sarcomas who were included in a clinical trial testing neoadjuvant chemotherapy. Exploiting the prognostic nomogram Sarculator, it found a benefit for chemotherapy when the predicted risk, based on patient and tumor characteristics, was high.

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.

Sarculator is a Good Model to Predict Survival in Resected Extremity and Trunk Sarcomas in US Patients.

BACKGROUND: Sarculator is an online validated nomogram that predicts overall survival of patients with resected, primary extremity sarcomas. However, its ability to accurately predict outcomes in US patients with sarcoma is unknown. PATIENTS AND METHODS: Patients from the National Cancer Data Base (NCDB) (2006-2016) with resected stage I-III primary extremity or trunk sarcoma were included. Predicted overall survival (pOS) was calculated using the Sarculator algorithm, which includes patient age, tumor size (cm), grade (1-3), and histology, and compared with actual overall survival (aOS). Harrell's C-index was calculated to determine the discriminatory ability of Sarculator (0.7 = good, 0.8 = strong, 1.0 = perfect model), and calibration plots were created. RESULTS: In total, 9738 patients were included. Five-year pOS was 73.7% compared with aOS of 68.9%. The C-index for the entire cohort was 0.726. By stage, the C-index was 0.730 for stage I, 0.708 for stage II, and 0.679 for stage III. By histology, C-indices were highest for leiomyosarcoma (0.745), myxofibrosarcoma (0.722), and other histologies (0.721). By sociodemographic variables, Sarculator performed better for patients < 50 years (C-index 0.722), of other/unknown race (C-index 0.781), with private insurance (C-index 0.715), treated at a center other than a community cancer programs (C-index > 0.7), and with no comorbidities (C-index 0.716). Outcomes by zip code educational attainment and income were not markedly different (all C-indices > 0.7). CONCLUSIONS: Sarculator is overall a good predictor of aOS and useful tool for clinicians to aid in survival prognostication. However, clinicians should be aware of populations for whom Sarculator's predictions may be less accurate. Future work could focus on enhancing the Sarculator algorithm specifically for US patients by including demographic variables.

Effect of Preoperative Treatment on the Performance of Predictive Nomograms in Primary Retroperitoneal Sarcoma.

BACKGROUND: Retroperitoneal sarcoma (RPS)-specific nomograms provide estimates of survival and recurrence risk following resection in the individual patient. The effect of preoperative treatment on nomogram performance has not been previously examined. Our aim was to evaluate the predictive accuracy of existing RPS-specific nomograms in patients managed at our center, where the majority of patients received preoperative radiation. PATIENTS AND METHODS: All patients who underwent curative treatment for primary RPS at Mount Sinai Hospital/Princess Margaret Hospital between 1996 and 2016 were identified. The performance of four previously published nomograms was assessed by measuring the agreement between nomogram-predicted and observed outcomes using Harrell's C-Index and level of calibration. Outcomes included in each of the nomograms [overall survival (OS), disease-free survival (DFS), disease-specific death (DSD), local recurrence (LR), distant recurrence (DR)] at each of the specified post-resection timepoints were examined. RESULTS: In total, 253 patients were included. When observed outcomes were compared with those predicted by each of the four nomograms, the C-Index ranged from 0.60 to 0.81, representing a wide range of predictive accuracy. The lowest C-Index was for prediction of LR. Calibration plots revealed that the Memorial Sloan Kettering Cancer Center (MSKCC) nomogram predicted a 5-year LR of 45%, whereas the observed LR was 24%. Overprediction of LR was detected in patients who had undergone preoperative radiotherapy, but not in patients treated with surgery alone. CONCLUSIONS: Preoperative radiotherapy appeared to preclude the use of the LR component of existing nomograms for primary RPS. Updated nomograms should be created to reflect this variable, particularly in light of the recently published STRASS trial results.

Refining the Approach to Patients with Primary Soft Tissue Sarcoma of the Extremities and Trunk Wall: Outcome Improvement Over Time at a Single Institution.

BACKGROUND: The improved outcome of extremity soft tissue sarcoma patients surgically treated until 2007 at the authors' institution was previously reported. This study updates the analysis at a later follow-up and extends the patients' cohort to assess changes in outcomes over time for extremity and superficial trunk soft tissue sarcoma (ESTSTS) treated at a single referral center. METHODS: All consecutive patients with primary localized adult-type ESTSTS surgically treated at the authors' institution between 1987 and 2017 were included and divided into group 1 (1987-2002) and group 2 (2003-2017) according to primary surgery year. Crude cumulative incidence (CCI) of sarcoma-specific mortality (SSM), local recurrence (LR), and distant metastases (DM) were calculated in a competing-risks framework. DM-free survival (DMFS) and post-DM survival were also assessed. RESULTS: The study identified 2382 patients. The median follow-up was 104 months (range, 63-127 months), and the post-DM follow-up was 76 months (range, 37-126 months). Since 2003, an increased adoption of preoperative treatments was observed: the use of chemotherapy, radiotherapy and combined chemoradiotherapy went from 10.5% to 23.7%, from 1.7% to 17.8%, and from 1% to 11.8% respectively. This change in treatment strategies was associated to an improvement in CCI-SSM (27.8% vs 19.5%; P < 0.001), CCI-LR (14.1 vs 7.5%; P < 0.001), DMFS (57.9% vs 65.8%; P = 0.004), and post-DM (12.2% vs 20.1%; P = 0.012), but not in CCI-DM. CONCLUSIONS: Increased adoption of preoperative treatments and greater availability of medical agents in the recent years were associated to better outcomes. New treatments are eagerly awaited for further improvement of outcome for ESTSTS patients because no major changes have been observed since 2003.

Delayed Gastric Emptying After Multivisceral Resection for Retroperitoneal Sarcoma.

INTRODUCTION: Delayed gastric emptying (DGE) is a common complication in surgery, but incidence and relevance following multivisceral resection are unknown. METHODS: Data from 100 consecutive patients treated for primary retroperitoneal sarcoma (RPS) were analyzed from our institutional prospectively maintained database from January 2019 to April 2020. DGE severity was graded according to the International Study Group of Pancreatic Surgery and classified as primary or secondary to other complications. The primary outcome was incidence and grade of clinically relevant DGE (grades B-C). Secondary outcomes were correlation with patient, tumor, and treatment characteristics, and non-DGE morbidity [Clavien-Dindo (CD) grade ≥ 3]. RESULTS: Forty-two patients developed DGE and 28 had clinically relevant DGE. DGE was primary in 10 patients and secondary in 18 patients; the most common associated complications were: infections (11/18, 61.1%), pancreatic leak (7/18, 38.9%), bleeding (6/18, 33.3%), and bowel leak (6/18, 33.3%). DGE was related to longer length of hospital stay (P < 0.001), ICU admission (P = 0.004), ICU length of stay (P = 0.001), postoperative complications (CD [Formula: see text] 3 in 14/28 in DGE patients vs 11/72 in no-DGE; P = 0.04), and re-operation (P = 0.03). With multivariate analysis, the independent risk factors for DGE were patient comorbidities (OR 1.05; 95% CI 1.01-1.1; P = 0.04) and tumor size (OR 1.05; 95% CI 1.0-1.1; P = 0.02). DISCUSSION: Following multivisceral resection, DGE is a clinically relevant event that can be caused by an underlying complication. Prompt diagnosis and treatment of both DGE and any underlying complications led to full recovery in all cases.

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

BACKGROUND: Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS. METHODS: An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor. RESULTS: Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS. CONCLUSIONS: Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery.

The evolution of adjuvant/neoadjuvant trials for resectable localized sarcoma.

Soft-tissue sarcomas are rare tumors arising from mesenchymal tissues. As a heterogeneous group comprising more than 50 types, the development of clinical trials remains challenging. Decision-making for neoadjuvant or adjuvant chemotherapy and radiation therapy is based on the available evidence of contemporary trials and multidisciplinary clinical judgment.