Histology-specific nomogram for primary retroperitoneal soft tissue sarcoma

Epidemiology, treatment and outcomes of primary renal sarcomas in adult patients

To assess epidemiology, clinical presentation, treatment and overall survival of adult patients with renal sarcomas, the 2004-2016 SEER and NCDB databases were queried for adult patients diagnosed with renal sarcoma, calculating average annual age-adjusted incidence rates (AAIR) and average annual percentage change (AAPC) as well as overall survival (OS). In n = 1279 included renal sarcoma patients, AAIR remained constant over the study period (average 0.53 cases/1million; AAPC = 0.7, p = 0.6). Leiomyosarcoma (AAIR 0.14 cases/1 million) and malignant rhabdoid tumors (0.06 cases/1 million) were most common. Sarcoma histiotypes demonstrated considerable heterogeneity regarding demographic and cancer-related variables. Patients presented with advanced local extent (T3 33.3%; T4 14.2%) or distant metastases (29.1%) and commonly underwent surgical resection (81.6%). Longer OS was independently associated with younger age, female sex, lower comorbidity index, low T stage, negative surgical margins, absence of tumor necrosis or distant metastases and leiomyosarcoma histiotype (multivariable p < 0.05 each). Treatment efficacy varied according to sarcoma histiotype (interaction p < 0.001). Accounting for 0.25% of renal malignancies, renal sarcomas include 43 histiotypes with distinct epidemiology, clinical presentation, outcomes and sensitivity to systemic therapy, thereby reflecting soft-tissue sarcoma behavior. Renal sarcoma treatment patterns follow recommendations by renal cancer guidelines with surgical resection as the cornerstone of therapy.

Extremity and Truncal Soft Tissue Sarcoma: Risk Assessment and Multidisciplinary Management

Extremity and truncal soft tissue sarcomas are a heterogeneous group of rare cancers that arise from mesenchymal tissues. Hence, the adoption of tailored risk assessment and prognostication tools plays a crucial role in optimizing the decision-making for which of the many possible treatment strategies to select. Management of these tumors requires a multidisciplinary strategy, which has seen significant development in recent decades. Surgery has emerged as the primary treatment approach, with the main goal of achieving microscopic negative tumor margins. To reduce the likelihood of local recurrence, loco-regional treatments such as radiation therapy and isolated limb perfusion are often added to the treatment regimen in combination with surgery. This approach also enables surgeons to perform limb-sparing surgery, particularly in cases where a positive tumor margin is expected. Chemotherapy may also provide a further benefit in decreasing the probability of local recurrence or reducing distant metastasis in selected patients. Selecting the optimal treatment strategy for these rare tumors is best accomplished by an experienced multi-disciplinary team.

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.

Survival nomograms for patients with retroperitoneal soft tissue sarcoma based on the SEER database and an external cohort

BACKGROUND

Retroperitoneal soft tissue sarcoma (RPS) is a quite rare disease,and new nomograms need to be constructed to predict the overall survival (OS) and cancer specific survival (CSS) of RPS patients.

METHODS

The clinical data of patients with RPS were extracted from the Surveillance, Epidemiology, and End Results (SEER) database and authors' hospital. The LASSO method and COX proportional hazard regression were used to screen independent risk factors which were used to develop nomograms. Nomograms was evaluated in terms of discrimination by consistency index (C-index) and calibration curve. Decision curve analysis (DCA) and integrated discrimination index (IDI) were performed to assess net benefit and the improvement of model, respectively. Kaplan-Meier method and log-rank test were applied to compare the survival difference between groups.

RESULTS

A total of 1164 cases were enrolled which were divided into training cohort (n = 814) and internal validation cohort (n = 350) at a 7:3 ratio. The discrimination of nomograms were good with C-index of 0.728 (95%CI = 0.704-0.752, R2 = 0.270), 0.754 (95%CI = 0.729-0.779, R2 = 0.281) for OS and CSS, respectively. Calibration curve showed good predictive accuracy of nomograms both in internal and external validation cohort, and IDI indicated that nomograms perform well than AJCC stage. Kaplan Meier curve and log-rank test uncovered statistically significance survival difference between high- and low-risk groups with P < 0.001 in terms of OS and CSS.

CONCLUSION

Novel nomograms predicting the OS and CSS of RPS patients perform well in discrimination, calibration, clinical benefit and IDI. These nomograms may facilitate risk stratification and making clinical decision.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

TNM classification of malignant tumors: Eighth edition for retroperitoneal liposarcoma. Ways to improve

AIM

This study was aimed at assessing the prognostic significance of the "TNM: Classification of Malignant Tumors" eighth edition (TNM8) in the most common retroperitoneal tumors - liposarcoma.

METHODS

The study included 192 patients with retroperitoneal liposarcoma (RLPS). The distribution of patients by stages and survival in accordance with the TNM8 were studied.

RESULTS

In the TNM8, only the degree of malignancy of the tumor has a prognostic value. The T-category does not reflect the actual size of the RLPS and is considered as T4 in 93%, which leads to inadequate staging. During the 15-year period, there were no cases with stages II and IIIA, and the survival rate was estimated only in patients with stages I and IIIB. The tumor node metastasis (TNM) classification with new values of the T-category was proposed by us, which demonstrated a more adequate distribution of patients by stages and the reliability of intergroup differences in the survival rate.

CONCLUSION

It is advisable to create a special TNM classification for RLPS, which makes up more than half of all retroperitoneal sarcomas. The TNM8 does not accurately reflect the prevalence of the tumor and the prognosis in RLPS. Revision of the T-staging is necessary to improve the accuracy of the prognosis in RLPS. The modified by us TNM classification demonstrated a more adequate distribution of patients by stages.

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

Objective

This 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.

Methods

In 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.

Results

With 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.

Conclusions

For 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.

Prognostic Factor Analysis and Nomogram Construction of Primary Retroperitoneal Liposarcoma: A Review of 10 Years of Treatment Experience in a Single Asian Cohort of 211 Cases

Objective

This study intended to retrospectively analyze the data of patients with primary retroperitoneal liposarcoma in a single Asian large-volume sarcoma center and to establish nomograms focused on PRLPS for predicting progression-free survival (PFS) and overall survival (OS).

Methods

A total of 211 patients treated surgically for primary, non-metastatic retroperitoneal liposarcoma during 2009–2021 were identified, and clinicopathologic variables were analyzed. PFS and OS nomograms were built based on variables selected by multivariable analysis. The discriminative and predictive ability of the nomogram was assessed by concordance index and calibration curve.

Results

The median follow-up time was 25 months. A total of 117 (56%) were well-differentiated, 78 (37%) were dedifferentiated, 13 (6%) were myxoid, and 3 (1%) were pleomorphic morphology. Compared to the western population cohort reported by the Memorial Sloan-Kettering Cancer Center, the median age of patients in this cohort was younger (57 vs. 63 years), the tumor burden was lower (20 vs. 26 cm), and the proportion of patients with R0 or R1 resection was higher (97% vs. 81%). The 5-year PFS rate was 49%, and factors independently associated with PFS were symptoms at visit, preoperative needle biopsy, histologic subtypes, and postoperative hospital stay. The 5-year OS rate was 72%. American Society of Anesthesiologists Physical Status and Clavien-Dindo classification were independently associated with OS. The concordance indexes for PFS and OS nomograms were 0.702 and 0.757, respectively. The calibration plots were excellent.

Conclusions

The proposed nomogram provided a favorable reference for the treatment of primary retroperitoneal liposarcoma patients.

[Active surgical approach for retroperitoneal liposarcoma]

OBJECTIVE

To assess the influence of active surgical approach on the long-term postoperative outcomes in patients with retroperitoneal liposarcoma.

MATERIAL AND METHODS

A retrospective study included 190 patients with retroperitoneal liposarcoma. The effect of malignancy grade, adjuvant chemotherapy, number of separate tumor nodes in primary neoplasm and the first relapse, as well as the number of previous total resections on survival rate was analyzed.

RESULTS

Overall and relapse-free survival is significantly worse in patients with high-grade retroperitoneal liposarcoma (G2-3) compared to low-grade (G1) tumor (p_log-rank=0.000). Multifocal growth of primary tumor (p=0.869; p_log-rank=0.607) and multiple (>1) separately located nodes in abdominal cavity and retroperitoneal space at the first relapse (p_log-rank=0.158 to 0.985) did not significantly impair prognosis after total resection of all types of retroperitoneal liposarcoma regardless malignancy grade. Adjuvant chemotherapy does not significantly improve relapse-free survival. Overall survival was significantly higher in patients who underwent ≥4 previous total resections compared to 1 surgical treatment for all types of retroperitoneal liposarcoma regardless malignancy grade (p=0.000; p_log-rank=0.001).

CONCLUSION

The only potentially radical treatment for patients with retroperitoneal liposarcoma is surgery. We reported the advantages of active surgical approach for improvement of long-term outcomes in patients with retroperitoneal liposarcoma.

Prognostic Nomogram and a Risk Classification System for Predicting Overall Survival of Elderly Patients with Fibrosarcoma: A Population-Based Study

Background

The objective of this study was to develop a nomogram model and risk classification system to predict overall survival in elderly patients with fibrosarcoma.

Methods

The study retrospectively collected data from the Surveillance, Epidemiology, and End Results (SEER) database relating to elderly patients diagnosed with fibrosarcoma between 1975 and 2015. Independent prognostic factors were identified using univariate and multivariate Cox regression analyses on the training set to construct a nomogram model for predicting the overall survival of patients at 3, 5, and 10 years. The receiver operating characteristic (ROC) curves and calibration curves were used to evaluate the discrimination and predictive accuracy of the model. Decision curve analysis was used for assessing the clinical utility of the model.

Result

A total of 357 elderly fibrosarcoma patients from the SEER database were included in our analysis, randomly classified into a training set (252) and a validation set (105). The multivariate Cox regression analysis of the training set demonstrated that age, surgery, grade, chemotherapy, and tumor stage were independent prognostic factors. The ROC showed good model discrimination, with AUC values of 0.837, 0.808, and 0.806 for 3, 5, and 10 years in the training set and 0.769, 0.779, and 0.770 for 3, 5, and 10 years in the validation set, respectively. The calibration curves and decision curve analysis showed that the model has high predictive accuracy and a high clinical application. In addition, a risk classification system was constructed to differentiate patients into three different mortality risk groups accurately.

Conclusion

The nomogram model and risk classification system constructed by us help optimize patients' treatment decisions to improve prognosis.

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.

Development and Validation of a Nomogram for Predicting Recurrence-Free Survival of Surgical Resected Retroperitoneal Liposarcoma

Background and Objectives

Surgical treatment is still the mainstay of curative therapy for retroperitoneal liposarcoma (RLPS), but often recurs after surgical resection. We aimed to establish a nomogram for postoperative recurrence of RLPS based on the Asian population.

Methods

Patients after surgical resection at the South Hospital of Zhongshan Hospital/Shanghai Public Health Clinical Center between August 2011 and December 2020 were included. The enrolled patients are randomly divided into training set and test set according to the ratio of 7:3. Prognostic factors were chosen based on Akaike Information Criterion, and the nomogram was built based on Cox regression and then internally validated through calibration plots and concordance index (C-index).

Results

A total of 447 patients were included. Gender, age, presentation status, organ invasion and FNCLCC grade were used to build nomogram. The calibration plots showed that RFS predicted probabilities are identical to the actual RFS rates. The C-index of the nomogram was 0.703 (95% CI 0.623–0.783) in the training set and 0.695 (95% CI 0.565–0.825) in test set.

Conclusion

The nomogram we established can accurately predict postoperative recurrence of RLPS patients for Asian population.

A multi-institutional validation study of prognostic nomograms for retroperitoneal sarcoma

BACKGROUND AND OBJECTIVES

Prognostic nomograms for patients undergoing resection of retroperitoneal sarcoma (RPS) include the Sarculator and Memorial Sloan Kettering (MSK) sarcoma nomograms. We sought to validate the Sarculator and MSK nomograms within a large, modern multi-institutional cohort of patients with primary RPS undergoing resection.

METHODS

Patients who underwent resection of primary RPS between 2000 and 2017 across nine high-volume US institutions were identified. Predicted 7-year disease-free (DFS) and overall survival (OS) and 4-, 8-, and 12-year disease-specific survival (DSS) were calculated from the Sarculator and MSK nomograms, respectively. Nomogram-predicted survival probabilities were stratified in quintiles and compared in calibration plots to observed survival outcomes assessed by Kaplan-Meier estimates. Discriminative ability of nomograms was quantified by Harrell's concordance index (C-index).

RESULTS

Five hundred and two patients underwent resection of primary RPS. Histologies included leiomyosarcoma (30%), dedifferentiated liposarcoma (23%), and well-differentiated liposarcoma (15%). Median tumor size was 14.0 cm (interquartile range [IQR], 8.5-21.0 cm). Tumor grade distribution was: Grade 1 (27%), Grade 2 (17%), and Grade 3 (56%). Median DFS was 31.5 months; 7-year DFS was 29%. Median OS was 93.8 months; 7-year OS was 51%. C-indices for 7-year DFS, and OS by the Sarculator nomogram were 0.65 (95% confidence interval [CI]: 0.62-0.69) and 0.69 (95%CI: 0.65-0.73); plots demonstrated good calibration for predicting 7-year outcomes. The C-index for 4-, 8-, and 12-year DSS by the MSK nomogram was 0.71 (95%CI: 0.67-0.75); plots demonstrated similarly good calibration ability.

CONCLUSIONS

In a diverse, modern validation cohort of patients with resected primary RPS, both Sarculator and MSK nomograms demonstrated good prognostic ability, supporting their ongoing adoption into clinical practice.

Gene Expression Changes Associated with Dedifferentiation in Liposarcoma Predict Overall Survival

Simple Summary

Previous studies have performed integrative analyses of genomic aberrations in soft tissue sarcomas. Utilising clinical information, groups have proposed nomograms for prediction of survival and recurrence in retroperitoneal sarcomas. Expanding on clinical nomogram prediction models with molecular classification of tumours may allow us to further identify clinical phenotypes within this heterogeneous group. We showed that a five-gene molecular prognostic panel can provide additional prognostic information in patients with retroperitoneal DDLS, independent of clinical features. A combined clinical and molecular prediction model may offer the best way to prognosticate patients for patient counselling and therapeutic decision making.

Abstract

Up to 10% of well-differentiated liposarcoma (WDLS) progress to dedifferentiated liposarcoma (DDLS). We aimed to identify gene expression changes associated with dedifferentiation and whether these were informative of tumour biology of DDLS. We analysed datasets from the Gene Expression Omnibus (GEO, ID = GSE30929) database to identify differentially expressed genes between WDLS (n = 52) and DDLS (n = 39). We validated the signature on whole and laser-capture microdissected samples from patients with tumours consisting of mixed WDLS and DDLS components. A subset of this signature was applied to an independent dataset from The Cancer Genome Atlas (TCGA, n = 58 DDLS) database to segregate samples based on gene expression and compared for recurrence and overall survival (OS). A 15-gene signature consisting of genes with increased expression in DDLS compared to WDLS was generated. This signature segregated WDLS and DDLS samples from patients with mixed component tumours and across multiple recurrences. A further subset of this signature, consisting of five genes (AQP7, ACACB, FZD4, GPD1, LEP), segregated DDLS in a TCGA cohort with a significant difference in OS (p = 0.019) and recurrence-free survival (RFS) (p = 0.061). The five-gene model stratified DDLS into prognostic groups and outperformed clinical factors in existing models in retroperitoneal DDLS.

A Nomogram Model to Predict Prognosis of Patients With Genitourinary Sarcoma

Objectives

The aim of this study is to evaluate the significant factors influencing the overall survival (OS) and recurrence free survival (RFS) and make an attempt to develop a nomogram for predicting the prognosis of patients with genitourinary sarcoma (GS).

Methods

Data on adult GS from 1985 to 2010 were collected. The impact of clinical factors on OS and RFS were estimated by Kaplan–Meier (KM) analysis, and differences between groups were analyzed by the log-rank test. To establish a nomogram, all patients were randomly divided into a training set (n = 125) and a testing set (n = 63). Cox proportion hazard model was utilized to assess the prognostic effect of variables. Then, a nomogram was established to estimate 1-, 3-, and 5-year OS based on Cox regression model. Subsequently, the nomogram was validated by a training set and a validation set.

Results

A total of 188 patients were enrolled into our study. Male patients with bladder sarcoma had better OS rather than RFS when stratified by gender (P = 0.022). According to histological subtypes, patients with leiomyosarcoma (LMS) undergoing chemotherapy were associated with favorable OS (P = 0.024) and RFS (P = 0.001). Furthermore, LMS in kidney sarcoma were associated with lower recurrence rate in comparison to rhabdomyosarcoma (RMS) (P = 0.043). Margin status after surgical excision markedly influenced the OS and RFS of GS patients and negative margins presented optimal prognosis. Chemotherapy was associated with improved OS for patients without surgery (P = 0.029) and patients with positive margins (P = 0.026). Based on the multivariate analysis of the training cohort, age, gender, surgery status, histological subtype, and chemotherapy were included in our nomogram for prediction of OS. The nomogram had sufficient power with concordance index (C-index) of OS: 0.770, 95%CI: 0.760–0.772 and area under curve (AUC) of OS: 0.759, 95%CI: 0.658–0.859 in the training set and with C-index of OS: 0.741, 95%CI: 0.740–0.765, and AUC of OS: 0.744, 95%CI: 0.576–0.913 in the validation set.

Conclusions

Adults GS is a group of extremely rare tumors with poor prognosis. Of all histological types, LMS is sensitive to chemotherapy. We highlighted the cardinal role of surgical resection and the importance of achieving negative margins. We identified the efficacy of chemotherapy for patients with positive margins and those without surgery as well. A nomogram is validated as an effective tool predicting short-term outcomes.

Conditional survival after surgical resection of primary retroperitoneal tumors: a population-based study

Background

The purpose of this study was to assess conditional survival (CS) after resection of primary retroperitoneal tumors (RPTs).

Methods

The data of 1594 patients with primary RPTs who underwent surgery between 2004 and 2016 were retrieved from the Surveillance Epidemiology and End Results (SEER) database. Multivariate Cox analysis was used to identify prognostic factors affecting overall survival (OS) and cancer-specific survival (CSS). CS was used to calculate the probability of survival for an additional 3 years after the patient had survived x years, according to the formulas: COS3 = OS (x + 3) /OS (x) and CCSS3 = CSS (x + 3)/CSS (x).

Results

The 1-, 3-, and 5-year OS rates of all patients were 89.8, 71.8, and 60.8%, while the 1-, 3-, and 5-year CSS rates were 91.9, 77.1, and 67.8%, respectively. Age, sex, FNCLCC grade, size, multifocality, histology, and chemotherapy were independent prognostic factors for OS and CSS. Among patients who survived for 1, 3, and 5 years, the COS3 rates were 72.9, 77.9, and 79.3%, and the CCSS3 rates were 78.1, 82.7, and 85.8%, respectively. Patients with poor clinicopathological characteristics achieved greater improvements in COS3 and CCSS3 rates, and the survival gaps between OS and COS3, as well as CSS and CCSS3 were more obvious.

Conclusion

Postoperative CS of RPTs was dynamic and increased over time. CS increased more significantly in patients with poor clinicopathological characteristics.

A novel nomogram for predicting local recurrence-free survival after surgical resection for retroperitoneal liposarcoma from a Chinese tertiary cancer center

BACKGROUND

Local recurrence is the most difficult postoperative challenge and the leading cause of death in patients with retroperitoneal liposarcoma (RLPS). We aimed to establish a postoperative nomogram exclusively focused on RLPS for predicting local recurrence-free survival (LRFS).

METHODS

A cohort of 124 patients after surgical resection with curative intent in the Peking University Cancer Hospital Sarcoma Center were included in the study. Demographic, clinicopathologic, and treatment variables were analyzed using the Cox regression model. Significant clinically relevant variables in multivariable analysis were incorporated into the RLPS-specific nomogram. The discriminative ability and predictive accuracy of the nomogram were assessed by calculating the concordance index and drawing a calibration plot.

RESULTS

At a median follow-up of 26.5 (interquartile range 10.9-39.4) months, 71 patients had recurrent disease. The 3-year and 5-year LRFS rates were 35.6% (95% confidence interval, 27.0-46.9%) and 28.2% (95% CI 15.8-38.6%), respectively. Multivariate analysis identified the French Federation of Cancer Centers Sarcoma Group (FNCLCC) grade and completeness of resection as independent predictors of LRFS. Variables included in our nomogram were: presentation status, multifocality, completeness of resection, histologic subtypes, and FNCLCC grade. The concordance index of our nomogram was 0.732 (95% CI 0.667-0.797) and the calibration plot was excellent.

CONCLUSIONS

Our novel nomogram for patients with resected RLPS could improve recurrence risk stratification to explore molecular analysis associated with recurrence.

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.

Role of neoadjuvant Radio-Chemotherapy for retroperitoneal Liposarcoma in primary and secondary surgical intervention

Abstract Background: Approximately 30–40 % of all retroperitoneal soft tissue tumors are sarcomas with liposarcoma prevailing in approximately 50% of these cases. Retroperitoneal liposarcomas typically show a high rate of local recurrence and late distant metastases. The aim of our retrospective analysis was to investigate the efficacy of treatment in our patients with liposarcoma. Methods: Thirty-four consecutive patients underwent surgery in our clinic between October 2004 and November 2017. Liposarcomas arising from the mesenteric or abdominal adipose tissue or the pelvis were excluded. In 2011 we had introduced neo-adjuvant therapy according to IAWS-Guidelines in patients younger than seventy without severe comorbidities to pretreatement. Results: Out of 34 patients, 23 (67,6%) presented with primary and 11 (32,4%) with recurrent disease. In 8 of the 27 patients (30 %), a radical resection (R0) could be achieved, and in 17 patients (63%) resection was marginal (R1). Time to recurrence was not affected by neoadjuvant radiotherapy. Patients that underwent systemic chemotherapy followed by radiotherapy developed earlier recurrences (p = 0.016). Overall survival appeared to be better in the neoadjuvant group but was not significant (0.080) Conclusions: Combining surgical resection with neoadjuvant radiation treatment showed survival benefits in primary but not recurrent disease. Repeated surgery stays a valid approach in carefully selected patients but all patients should be referred to a center of expertise in multimodal treatment approaches for retroperitoneal liposarcomas.

Malnutrition and Perioperative Nutritional Support in Retroperitoneal Sarcoma Patients: Results from a Prospective Study

INTRODUCTION

Retroperitoneal soft tissue sarcomas (RPSs) are mesenchymal neoplasms. The prevalence of protein energetic malnutrition (PEM) and its impact in RPS patients who were candidates for surgery is unknown.

MATERIALS AND METHODS

A prospective feasibility study enrolled 35 patients with primary RPS who were candidates for extended multivisceral resection. PEM was screened at enrollment. Preoperative high protein β-hydroxy-β-methyl butyrate oral nutritional support (ONS) was provided according to the degree of PEM. After surgery, nutritional support followed standard practice, targeting at least 1 g/kg/day protein and 20 kcal/kg/day caloric intake within the third postoperative day (POD). PEM was re-evaluated before surgery on POD 10, and at 4 and 12 months after surgery. Primary outcomes were the patient's compliance to preoperative ONS and the physician's compliance to postoperative nutritional targets.

RESULTS

PEM was documented in 46% of patients at baseline; ONS met a 91% adherence (overall well tolerated). After ONS, PEM reduced to 38% (p = 0.45). The postoperative caloric target was reached on day 4.1 (standard error ± 2.7), with a protocol adherence rate of 52%. On POD 10, 91% of patients experienced PEM, the worsening of which was greater after resection of four or more organs (p = 0.06). At 4 and 12 months after surgery, almost all patients had fully recovered. A significant correlation between PEM at surgery and postoperative complications was found (p = 0.04).

CONCLUSIONS

Relevant PEM prevalence in RPS is documented for the first time. PEM correlates with greater morbidity. In this setting, preoperative ONS was feasible and well-tolerated. Disease-related factors for PEM and the ideal perioperative caloric target in the context of extended multivisceral resection need to be further investigated. Nutritional support should be included in enhanced recovery after surgery programs for RPS.

TRIAL REGISTRY

ClinicalTrials.gov identifier: NCT03877588.

An Evaluation of the Eighth Edition of the American Joint Committee on Cancer (AJCC) Staging System for Retroperitoneal Sarcomas Using the National Cancer Data Base (NCDB): Does Size Matter?

OBJECTIVES

Retroperitoneal sarcomas (RPS) are often large at diagnosis calling into question the seventh edition AJCC size classification of <5 cm (T1) or ≥5 cm (T2). The eighth edition expands T stage into 4 categories (T1: ≤5 cm, T2: 5<x≤10 cm, T3: 10<x≤15 cm, T4: >15 cm). We evaluated the prognostic ability of the eighth edition using the National Cancer Database (NCDB).

METHODS

Patients with RPS treated between 1998 and 2011 were identified from the NCDB; overall survival (OS) was compared.

RESULTS

Of the 6427 patients identified, 9% had tumors ≤5 cm (n=580), 19.4% 5<x≤10 cm (n=1246), 20.2% 10<x≤15 cm (n=1298) and 47.4% >15 cm (n=3045). With the eighth edition, stage II patients (G2/3 ≤5 cm) have a similar OS to stage IIIA patients (G2/3 5 cm<x≤10 cm), and patients with larger tumors (stage IIIB, G2/3>10 cm) show a decrease in OS. Tumor size as a continuous variable had a modest effect on survival (HR, 1.004; P=0.04). On multivariate analysis, higher T-stage was associated with decreased OS (T4 HR, 1.3; P<0.001) but high grade and incomplete resection (R2) were stronger prognostic factors. The c-index for both editions were similar (80.13 eighth vs. 80.08 seventh).

CONCLUSIONS

The eighth edition AJCC staging system for retroperitoneal sarcoma incorporates larger tumor size parameters that better characterize most patients, but tumor size alone is only a modest predictor of outcome.

Recurrent Retroperitoneal Liposarcoma: a Case Report and Literature Review

This is a case report of a 61-year-old male patient, presented with fifth recurrence of retroperitoneal liposarcoma and operated for six times. Literature review on retroperitoneal liposarcoma biology, recurrence pattern, role of surgery in primary tumor, and recurrent tumor, adjuvant therapy, role of multivisceral resection, and palliative surgery.

Neoadjuvant chemotherapy in soft tissue sarcomas: latest evidence and clinical implications

Soft tissue sarcomas are a rare and multifaceted group of solid tumours. Neoadjuvant chemotherapy is increasingly used to limit loss of function after wide surgical excision with the ultimate aim of improving patient survival. Recently, advances in the identification of effective treatment strategies and improvements in patient risk stratification have been reached. A randomized trial demonstrated that neoadjuvant epirubicin and ifosfamide improves survival of patients affected by five high-risk soft tissue sarcoma histologies of trunk and extremities, including undifferentiated pleomorphic sarcoma, myxoid liposarcoma, synovial sarcoma, malignant peripheral nerve sheath tumours, and leiomyosarcoma. Selection of patients for these treatments is expected to be improved by the eighth edition of the American Joint Committee on Cancer (AJCC) TNM staging system, as it tailors T-stage categories on primary tumour site and considers a prognostic nomogram for retroperitoneal sarcoma, which also includes soft tissue sarcoma histology and other patient and tumour features not directly included in the TNM staging. Within this framework, this article will present neoadjuvant treatment strategies for high-risk soft tissue sarcoma, emphasizing the most recent advances and discussing the need for further research to improve the effectiveness of neoadjuvant treatments.

Retroperitoneal liposarcoma: current insights in diagnosis and treatment

Retroperitoneal liposarcoma (RLS) is a rare, biologically heterogeneous tumor that present considerable challenges due to its size and deep location. As a consequence, the majority of patients with high-grade RLS will develop locally recurrent disease following surgery, and this constitutes the cause of death in most patients. Here, we review current insights and controversies regarding histology, molecular biology, extent of surgery, (neo)adjuvant treatment, and systemic treatment including novel targeted agents in RLS.

Surgical management of retroperitoneal and pelvic sarcomas

Management of retroperitoneal sarcomas presents technical and oncological challenges. Imaging is crucial for diagnosis and to define local tumor extent. Complete gross resection at initial presentation is the best chance for cure, but there is controversy as to how this can be best achieved. There is a long-term risk of local recurrence, which is best treated with repeat resection if feasible. The roles of radiation and chemotherapy remain undefined.

Model-based estimation of measures of association for time-to-event outcomes

Background

Hazard ratios are ubiquitously used in time to event applications to quantify adjusted covariate effects. Although hazard ratios are invaluable for hypothesis testing, other adjusted measures of association, both relative and absolute, should be provided to fully appreciate studies results. The corrected group prognosis method is generally used to estimate the absolute risk reduction and the number needed to be treated for categorical covariates.

Methods

The goal of this paper is to present transformation models for time-to-event outcomes to obtain, directly from estimated coefficients, the measures of association widely used in biostatistics together with their confidence interval. Pseudo-values are used for a practical estimation of transformation models.

Results

Using the regression model estimated through pseudo-values with suitable link functions, relative risks, risk differences and the number needed to treat, are obtained together with their confidence intervals. One example based on literature data and one original application to the study of prognostic factors in primary retroperitoneal soft tissue sarcomas are presented. A simulation study is used to show some properties of the different estimation methods.

Conclusions

Clinically useful measures of treatment or exposure effect are widely available in epidemiology. When time to event outcomes are present, the analysis is performed generally resorting to predicted values from Cox regression model. It is now possible to resort to more general regression models, adopting suitable link functions and pseudo values for estimation, to obtain alternative measures of effect directly from regression coefficients together with their confidence interval. This may be especially useful when, in presence of time dependent covariate effects, it is not straightforward to specify the correct, if any, time dependent functional form. The method can easily be implemented with standard software.

Retroperitoneal sarcomas: patterns of care at diagnosis, prognostic factors and focus on main histological subtypes: a multicenter analysis of the French Sarcoma Group

BACKGROUND

Retroperitoneal sarcomas (RPS) are heterogeneous. No previous study has investigated the impact of specialized surgery, evaluated locoregional relapse (LRR), abdominal sarcomatosis and distant metastatic relapse as separate events, or considered histological subtypes separately. This study addresses these specific points in a homogeneous cohort of patients with completely resected primary RPS.

PATIENTS AND METHODS

We conducted a retrospective analysis of adult patients diagnosed with a RPS between 1 January 1988 and 31 December 2008 and eventually referred to one of 12 centers of the French Sarcoma Group. All cases were centrally reviewed by an expert pathologist.

RESULTS

Five hundred eighty-six patients were included. Median follow-up was 6.5 years [95% confidence interval (CI) 5.9-7.1]. Five hundred thirty-seven patients had localized disease and 389 patients (76%) had macroscopically complete resection of the tumor. In this latter group, the 5-year LRR-free survival rate was 46% [41-52] and the 5-year overall survival (OS) rate was 66% [61-71]. In multivariate analysis, gender, adjacent organ involvement, specialization of the surgeon, piecemeal resection and perioperative radiotherapy were independently associated with LRR. Specialization of the surgeon and piecemeal resection were independently associated with abdominal sarcomatosis whereas histology and adjacent organ involvement were independently associated with distant metastasis. Age, gender, grade, adjacent organ involvement and piecemeal resection were significantly associated with OS. Prognostic factors for LRR and OS were analyzed in well-differentiated and dedifferentiated liposarcomas and leiomyosarcomas. Grade 3 was an independent prognostic factor for OS of dedifferentiated liposarcomas.

CONCLUSION

This study underlines the crucial role of pretherapeutic assessment and meticulous histological examination of RPS as well as the need to consider histological subtypes separately. Surgery in a specialized center and avoidance of piecemeal resection stand out as the two most important prognostic factors for RPS and highlight the importance of treating these patients in specialized centers.

Recurrent abdominal liposarcoma: Analysis of 19 cases and prognostic factors

AIM: To evaluate the clinical outcome of re-operation for recurrent abdominal liposarcoma following multidisciplinary team cooperation.

METHODS: Nineteen consecutive patients who had recurrent abdominal liposarcoma underwent re-operation by the retroperitoneal sarcoma team at our institution from May 2009 to January 2012. Patient demographic and clinical data were reviewed retrospectively. Multidisciplinary team discussions were held prior to treatment, and re-operation was deemed the best treatment. The categories of the extent of resection were as follows: gross total resection (GTR), palliative resection and partial resection. Surgical techniques were divided into discrete lesion resection and combined contiguous multivisceral resection (CMR). Tumor size was determined as the largest diameter of the specimen. Patients were followed up at approximately 3-monthly intervals. For survival analysis, a univariate analysis was performed using the Kaplan-Meier method, and a multivariate analysis was performed using the Cox proportional hazards model.

RESULTS: Nineteen patients with recurrent abdominal liposarcoma (RAL) underwent 32 re-operations at our institute. A total of 51 operations were reviewed with a total follow-up time ranging from 4 to 120 (47.4 ± 34.2) mo. The GTR rate in the CMR group was higher than that in the non-CMR group (P = 0.034). CMR was positively correlated with intra-operative bleeding (correlation coefficient = 0.514, P = 0.010). Six cases with severe postoperative complications were recorded. Patients with tumor sizes greater than 20 cm carried a significant risk of profuse intra-operative bleeding (P = 0.009). The ratio of a highly malignant subtype (dedifferentiated or pleomorphic) in recurrent cases was higher compared to primary cases (P = 0.027). Both single-factor survival using the Kaplan-Meier model and multivariate analysis using the Cox proportional hazards model showed that overall survival was correlated with resection extent and pathological subtype (P < 0.001 and P = 0.02), however, relapse-free interval (RFI) was only correlated with resection extent (P = 0.002).

CONCLUSION: Close follow-up should be conducted in patients with RAL. Early re-operation for relapse is preferred and gross resection most likely prolongs the RFI.

Toward better soft tissue sarcoma staging: building on american joint committee on cancer staging systems versions 6 and 7

BACKGROUND

Based on review of patient data in case conferences over time, we hypothesized that clinically relevant data are omitted in routine soft tissue sarcoma staging.

METHODS

We examined subsets of a prospectively collected single institution soft tissue sarcoma database with respect to criteria of the AJCC versions 6 (2002) and 7 (2010) staging systems and examined their clinical outcomes.

RESULTS

Relapse-free survival decreases with increasing primary tumor size in four categories, versus two categories used in AJCC 6 and 7 staging. Disease-specific survival decreases over three categories. Conversely, omission of tumor depth as a prognostic factor in version 7 appears supported, since tumor depth is not an independent risk factor for disease-specific survival by multivariate analysis. Patients with nodal disease and no other metastases fare better than patients with other metastases, but have inferior outcomes compared with patients with large high-grade tumors without nodal metastasis. Multivariate analysis identified size, site, grade, age, nodal metastatic disease, and other metastatic disease as independent risk factors for disease-specific survival. Versions 6 and 7 criteria are tacit regarding anatomic site and histology for tumors with identical FNCLCC grade.

CONCLUSIONS

Improved patient risk assessment may be achieved by staging using a larger number of size categories. Staging system refinements come at the cost of a larger number of staging categories. Histology or site-specific staging systems, nomograms or Bayesian belief networks may provide more accurate means to assess clinical outcomes.

Retroperitoneal liposarcomas: the experience of a tertiary Asian center

BACKGROUND

Liposarcoma is the single most common soft tissue sarcoma in the retroperitoneum.

MATERIALS AND METHODS

A retrospective review of patients with primary retroperitoneal liposarcoma treated between June 1990 and June 2005 were conducted to evaluate the clinical results of resection for retroperitoneal liposarcomas (RPLS) and the prognostic factors for disease recurrence and patient survival in an Asian population.

RESULTS

Twenty-one patients operated on for curative intent (12 Males, 9 Females; mean age: 52.4 years) were evaluated. Of these, 13 presented with tumors that were well differentiated (61.9%), 4 (19.0%) with myxoid/round cell, 3 (14.3%) with dedifferentiated and 1(4.8%) with pleomorphic morphology. The median tumor burden was 36 cm (9-83). Median follow-up time was 62 months. There was no peri-operative mortality and morbidity occurred in 6(28.6%) patients. Surgical margins were involved in 10(47.6%) patients. Resection of contiguous organs was required in 15(71.4%) to achieve gross surgical margins. Eleven out of the 21(52%) of the patients had recurrence of the tumor. Median disease-free survival was 19 months and the overall 3- and 5-year survival rate was 87% and 49% respectively.

CONCLUSION

An aggressive surgical approach in both primary and recurrent RPLS in our institution is associated with 3- and 5-year survival rate of 87% and 49% respectively. Contiguous organ resection is often required to achieve local control.