Evaluation of a Clinically Applicable Post-Surgical Classification System for Primary Retroperitoneal Soft-Tissue Sarcoma

Primary Tumor Resection in Leiomyosarcoma Patients With Synchronous Isolated Lung Metastases: A National Cancer Database Study

INTRODUCTION

Up to half of patients with leiomyosarcoma (LMS) present with distant metastases, most commonly in the lungs. Despite guidelines around managing metachronous oligometastatic disease, limited evidence exists for synchronous isolated lung metastases (SILMs). Our histology-specific study describes management patterns and outcomes for patients with LMS and SILM across disease sites.

METHODS

We used the National Cancer Database to analyze patients with LMS of the retroperitoneum, extremity, trunk/chest/abdominal wall, and pelvis with SILM. Patients with extra-pulmonary metastases were excluded. We identified factors associated with primary tumor resection and receipt of metastasectomy. Outcomes included median, 1-year, and 5-year overall survival (OS) across treatment approaches using log-rank tests, Kaplan-Meier curves, and Cox proportional hazard models.

RESULTS

We identified 629 LMS patients with SILM from 2004 to 2017. Patients were more likely to have resection of their primary tumor or lung metastases if treated at an academic center compared to a community cancer center. Five year OS for patients undergoing both primary tumor resection and metastasectomy was 20.9% versus 9.2% for primary tumor resection alone, and 2.6% for nonsurgical patients. Median OS for all-comers was 15.5 mo. Community treatment site, comorbidity score, and larger primary tumors were associated with worse survival. Chemotherapy, primary resection, and curative intent surgery predicted improved survival on multivariate Cox regression.

CONCLUSIONS

An aggressive surgical approach to primary LMS with SILM was undertaken for select patients in our population and found to be associated with improved OS. This approach should be considered for suitable patients at high-volume centers.

Surgically treated pelvic liposarcoma and leiomyosarcoma: The effect of tumor size on cancer-specific survival

INTRODUCTION

In soft tissue pelvic liposarcoma and leiomyosarcoma, it is unknown whether a specific tumor size cut-off may help to better predict prognosis, defined as cancer-specific survival (CSS). We tested whether different tumor size cut-offs, could improve CSS prediction.

MATERIALS AND METHODS

Surgically treated non-metastatic soft tissue pelvic sarcoma patients were identified (Surveillance, Epidemiology, and End Results 2004-2019). Kaplan-Meier plots, univariable and multivariable Cox-regression models and receiver operating characteristic-derived area under the curve (AUC) estimates were used.

RESULTS

Overall, 672 (65 %) liposarcoma (median tumor size 11 cm, interquartile range [IQR] 7-16) and 367 (35 %) leiomyosarcoma (median tumor size 8 cm, IQR 5-12) patients were identified. The p-value derived ideal tumor size cut-off was 17.1 cm, in liposarcoma and 7.0 cm, in leiomyosarcoma. In liposarcoma, according to p-value derived cut-off, five-year CSS rates were 92 vs 83 % (≤17.1 vs > 17.1 cm). This cut-off represented an independent predictor of CSS and improved prognostic ability from 83.8 to 86.8 % (Δ = 3 %). Similarly, among previously established cut-offs (5 vs 10 vs 15 cm), also 15 cm represented an independent predictor of CSS and improved prognostic ability from 83.8 to 87.0 % (Δ = 3.2 %). In leiomyosarcoma, according to p-value derived cut-off, five-year CSS rates were 86 vs 55 % (≤7.0 vs > 7.0 cm). This cut-off represented an independent predictor of CSS and improved prognostic ability from 68.6 to 76.5 % (Δ = 7.9 %).

CONCLUSIONS

In liposarcoma, the p-value derived tumor size cut-off was 17.1 cm vs 7.0 cm, in leiomyosarcoma. In both histologic subtypes, these cut-offs exhibited the optimal statistical characteristics (univariable, multivariable and AUC analyses). In liposarcoma, the 15 cm cut-off represented a valuable alternative.

Influence of nutritional status and body composition on postoperative events and outcome in patients treated for primary localized retroperitoneal sarcoma

BACKGROUND

Retroperitoneal sarcomas (RPS) are rare tumours of mesenchymal origin, commonly presented as a large tumour mass at time of diagnosis. We investigated the impact of body composition on outcome in patients operated on for primary localized RPS.

PATIENTS AND METHODS

We retrospectively analysed data for all patients operated on for primary RPS at our institution between 1999 and 2020. Preoperative skeletal muscle area (SMA), visceral and subcutaneous adipose tissue area (VAT and SAT) and muscle radiation attenuation (MRA) were calculated using computed tomography scans at the level of third lumbar vertebra. European Working Group on Sarcopenia in Older People (EWGSOP2) criteria were applied to define myopenia. Using maximum log-rank statistic method we determined the optimal cut-off values of body composition parameters. Myosteatosis was defined based on determined MRA cut-offs.

RESULTS

In total 58 patient were eligible for the study. With a median follow-up of 116 months, the estimated 5-year overall survival (OS) and local-recurrence free survival (LRFS) were 66.8% and 77.6%, respectively. Patients with myopenia had significantly lower 5-year OS compared to non-myopenic (p = 0.009). Skeletal muscle index and subcutaneous adipose tissue index predicted LRFS on univariate analysis (p = 0.052 and p = 0.039, respectively). In multivariate analysis high visceral-to-subcutaneous adipose tissue area ratio (VSR) independently predicted higher postoperative complication rate (89.2% vs. 10.8%, p = 0.008). Myosteatosis was associated with higher postoperative morbidity.

CONCLUSIONS

Myopenia affected survival, but not postoperative outcome in RPS. Visceral obesity, VSR (> 0.26) and myosteatosis were associated with higher postoperative morbidity. VSR was better prognostic factor than VAT in RPS.

Deep Learning Networks for Automatic Retroperitoneal Sarcoma Segmentation in Computerized Tomography

The volume estimation of retroperitoneal sarcoma (RPS) is often difficult due to its huge dimensions and irregular shape; thus, it often requires manual segmentation, which is time-consuming and operator-dependent. This study aimed to evaluate two fully automated deep learning networks (ENet and ERFNet) for RPS segmentation. This retrospective study included 20 patients with RPS who received an abdominal computed tomography (CT) examination. Forty-nine CT examinations, with a total of 72 lesions, were included. Manual segmentation was performed by two radiologists in consensus, and automatic segmentation was performed using ENet and ERFNet. Significant differences between manual and automatic segmentation were tested using the analysis of variance (ANOVA). A set of performance indicators for the shape comparison (namely sensitivity), positive predictive value (PPV), dice similarity coefficient (DSC), volume overlap error (VOE), and volumetric differences (VD) were calculated. There were no significant differences found between the RPS volumes obtained using manual segmentation and ENet (p-value = 0.935), manual segmentation and ERFNet (p-value = 0.544), or ENet and ERFNet (p-value = 0.119). The sensitivity, PPV, DSC, VOE, and VD for ENet and ERFNet were 91.54% and 72.21%, 89.85% and 87.00%, 90.52% and 74.85%, 16.87% and 36.85%, and 2.11% and -14.80%, respectively. By using a dedicated GPU, ENet took around 15 s for segmentation versus 13 s for ERFNet. In the case of CPU, ENet took around 2 min versus 1 min for ERFNet. The manual approach required approximately one hour per segmentation. In conclusion, fully automatic deep learning networks are reliable methods for RPS volume assessment. ENet performs better than ERFNet for automatic segmentation, though it requires more time.

Multidisciplinary Management of Retroperitoneal Sarcoma: Diagnosis, Prognostic Factors and Treatment

Simple Summary

The management of retroperitoneal sarcomas can be challenging due to the variety of their presentation, histopathological types, and behaviours. This literature review provides a comprehensive and practical overview of the management of retroperitoneal sarcomas, focusing on diagnostic challenges, prognostic factors, multidisciplinary aspects of treatment and new research perspectives.

Abstract

Retroperitoneal sarcomas (RPS) are rare cancers whose management can be challenging due to various presentation patterns, multiple organ involvement, and a high local and distant recurrence rate. Histopathology and prognostic factors analysis are essential to predict the behaviour of the disease and plan the best therapeutic strategy. To date, surgery is still the main therapeutic option that guarantees a chance of cure from the primary disease. While chemotherapy and radiotherapy seem to be good options for controlling metastatic and recurrent irresectable disease, their role in the treatment of primary RPS remains unclear. This literature review aims to provide a comprehensive overview of the multidisciplinary aspects of RPS management in high-volume centres, summarising the diagnostic path, the prognostic factors, and the most suitable therapeutic options.

Retroperitoneal tumors: Review of diagnosis and management

Retroperitoneal tumors are extremely rare tumors occurring in the retroperitoneum. Retroperitoneal tumors are divided into benign tumors and malignant tumors, including retroperitoneal sarcoma. Approximately 70-80% of primary retroperitoneal soft-tissue tumors are malignant; however, these only account for 0.1-0.2% of all malignancies. Retroperitoneal sarcoma is an orphan malignant disease with a low incidence. The information on benign retroperitoneal tumors is limited. The American Joint Committee on Cancer/TNM classification updated to the 8th edition in 2017. In 2010, three new drugs for soft tissue sarcoma were approved based on the results of phase III trials, but the histological subtypes of the patients enrolled in the trials of each drug differed. Recently, in addition to surgery for retroperitoneal sarcoma, the effectiveness of perioperative radiation therapy has become interesting. For malignant retroperitoneal tumors and retroperitoneal sarcoma, survival improvement and locoregional recurrence prevention can be undertaken by carrying out surgery to secure negative margins with wide and combined resection of some adjacent organs, and cooperation with a trained medical team comprising of radiologists, pathologists and medical oncologists in centralized hospitals. Some clinical trials aimed at further improving treatment results by adding preoperative chemotherapy and radiation therapy based on histological confirmation using a correct needle biopsy are in progress. In recent years, molecular profiling has been used to select eligible patients for chemotherapy. In the future, precision medicine with next-generation sequencing technology will be expected among the diverse and potential future treatments for retroperitoneal sarcoma. In this review, we summarized the current state of retroperitoneal tumors and retroperitoneal sarcoma.

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.

Surgically Treated Retroperitoneal Sarcoma: A Population-based Competing Risks Analysis

BACKGROUND

Data regarding the relationship between non-disease-specific (NDSM) and disease-specific mortality (DSM) in patients with surgically treated nonmetastatic retroperitoneal sarcoma (nmRPS) are lacking.

OBJECTIVE

To examine the rates of NDSM and DSM among patients with surgically treated nmRPS.

DESIGN, SETTING AND PARTICIPANTS

We used the Surveillance, Epidemiology and End Results (SEER) database (2004-2014) to obtain data for patients with surgically treated nonmetastatic RPS.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

The 5-yr DSM and NDSM rates were generated via competing risks regression (CRR) methodologies. Multivariable CRR models were used to test the effects of age, histologic subtype, grade, size, and radiotherapy (RT) status on NDSM and DSM.

RESULTS AND LIMITATIONS

Overall, 231 (26.8%) and 57 patients (6.7%) died from DSM and NDSM, respectively. Following stratification according to age, histologic subtype, grade, size, and RT status, the proportion of patients who succumbed to NDSM was higher for patients with age above the median, liposarcoma histologic subtype, low grade, and tumor size ≥17cm. DSM rates were also higher among patients with age above the median, leiomyosarcoma histologic subtype, high grade, and tumor size ≥17cm. Multivariable CRR models revealed that age above the median was associated with higher NDSM (hazard ratio [HR]1.7, 95% confidence interval [CI] 1.1-2.7; p=0.019). Conversely, leiomyosarcoma (HR 1.9, 95% CI 1.4-2.6; p<0.0001), sarcoma not otherwise specified (HR 2.4, 95% CI 1.5-3.8; p<0.0001) and other RPS (HR 2, 95% CI 1.2-3.4; p=0.01) histologic subtypes, high grade (HR 3, 95% CI 2.3-4; p<0.0001), and tumor size above the median (HR 1.4, 95% CI 1.1-3.8; p=0.012) were associated with higher DSM. This is a retrospective study and misclassification bias may be present because of the reliability of the distinction between DSM and NDSM.

CONCLUSIONS

The impact of NDSM in surgically treated nmRPS is not trivial, particularly among patients with favorable characteristics such as liposarcoma histologic subtype and low-grade tumors.

PATIENT SUMMARY

Mortality from causes not related to the specific disease is important in patients with retroperitoneal sarcoma (RPS) treated surgically. In particular, patients with good tumor characteristics, namely liposarcoma histologic subtype and low grade, most often do not die from their cancer but succumb to causes other than RPS. Unfortunately, tumor characteristics and radiotherapy administration shed relatively little light on predicting mortality from causes other than cancer in patients with surgically treated RPS. Our report compares the risk of dying from RPS with that of dying from other causes according to the type of surgically treated sarcoma.

Improved survival for extremity soft tissue sarcoma treated in high-volume facilities

BACKGROUND AND OBJECTIVES

The purpose of this investigation was to determine the effect of hospital volume on treatment decisions, treatment results, and overall patient survival in extremity soft tissue sarcoma.

METHODS

The National Cancer Database was used to identify patients ≥18 years of age with non-metastatic soft tissue sarcoma of the extremity treated with surgery. Patients in high- and low-volume centers were matched by propensity score and placed into two equal comparative groups of 2437 patients each.

RESULTS

Chemotherapy was used at a higher rate in high-volume centers (22% vs 17%, P < 0.001) and external beam radiation usage was similar (55% vs 52%, P = 0.108). There was a lower incidence of positive margins in high-volume centers (12% vs 17%, P < 0.001). There was no significant difference in the rates of limb salvage surgery or readmissions at high-volume hospitals compared to low-volume. In a multivariate Cox proportional hazards model, low-volume facilities demonstrated diminished overall survival at all time points (hazard ratio at 5 years = 1.24, 95%CI 1.10-1.39).

CONCLUSIONS

Treatment at high-volume hospitals was associated with fewer positive margins and increased overall survival at 2, 5, and 10 years. Continued efforts should focus on optimizing the balance between patient access to specialty care and experience of the treating center.

Retroperitoneal Soft Tissue Sarcoma: Prognostic Factors and Therapeutic Approaches

Aims and Background

Retroperitoneal sarcomas are a rare group of malignant soft tissue tumors with a generally poor prognosis. The aim of the study was to assess clinical, pathological and treatment-related factors affecting prognosis in patients with retroperitoneal sarcomas.

Methods and Study Design

The hospital records of 73 patients who underwent surgical exploration at our unit for primary retroperitoneal sarcomas between 1984 and 2003 were reviewed. Factors influencing overall and disease-free survival were analyzed for all patients and for those who underwent complete surgical resection.

Results

The complete resectability rate was 69.8% (51/73). Operative mortality and morbidity rates were 2.7% and 21.9%, respectively. For patients who underwent complete resection, the 5-year survival rate was 58.3%, whereas it was 0% in cases of incomplete or no resection (P <0.001). Local recurrence rate was 37.2%. Incomplete gross surgical resection and microscopic infiltration of margins were the most important independent predictors of a poor prognosis.

Conclusions

The present study confirmed the importance of an aggressive surgical management for retroperitoneal sarcomas to offer these patients the best chance for long-term survival.

Treatment of retroperitoneal sarcoma: current standards and new developments

PURPOSE OF REVIEW

Retroperitoneal sarcomas are rare tumors and with complex treatment. In this manuscript we give an overview of current standards in treatment of this disease and discuss new developments.

RECENT FINDINGS

Surgery with complete resection of the primary tumor is still the only curative modality. The role of preoperative radiotherapy is not clear and is currently being investigated in a clinical trial. Neo-adjuvant chemotherapy is not the standard of care but can be considered occasionally when complete resection is uncertain. Local and distant recurrent disease carries a dismal prognosis, although long-term survival can be achieved. Liposarcomas tend to recur locally, whereas distant recurrences are more often seen in leiomyosarcoma and other subtypes. Outcome improves when patients are treated in high volume sarcoma centers. In the metastatic setting, newer systemic agents have recently been approved.

SUMMARY

Treatment of retroperitoneal sarcomas is complex and all patients should be treated in multidisciplinary sarcoma centers. Increasing international collaboration of expert centers in sharing expertise and performing clinical trials might lead to better treatment and improved survival.

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.

Soft tissue sarcoma nomograms and their incorporation into practice

The accurate prediction of prognosis in patients with soft tissue sarcoma (STS) is a challenging issue. Extreme variability in the clinical and pathological characteristics of this family of tumors hinders the simple stratification of patients into meaningful prognostic cohorts. Precision medicine tools for the prediction of prognosis, such as nomograms, enable personalized computation of outcome based on clinical and pathological characteristics of both patient and tumor. The eighth edition of the American Joint Committee on Cancer staging manual moved from a "population-based" to a "personalized" approach endorsing high-quality nomograms to improve clinician prediction ability in definite patient subgroups. The first nomogram for STS was published in 2002, and this was followed by several prognostic predictors offered to clinicians. Focusing on a specific STS subgroup or site, nomograms can take into consideration highly specific factors relevant only in that particular scenario, thereby maximizing prognostic ability. The objective of this review was to critically evaluate available nomograms for patients with STS to provide clinicians and researchers with a choice of the most optimal tool for each specific patient. Cancer 2017;123:2802-20. © 2017 American Cancer Society.

Tumor biology remains the main determinant of prognosis in retroperitoneal sarcomas: a 14-year single-center experience

AIM

To review our experience in the management of retroperitoneal sarcomas (RPSs) in a single institution, with a predominantly Asian population, and identify associated prognostic factors for overall survival (OS), disease-free survival (DFS) and local recurrence.

MATERIALS AND METHODS

All RPSs diagnosed and managed at our center between January 2000 and March 2014 were included. Exclusion criteria included patients whose medical records were untraceable and patients who underwent biopsy but did not undergo resection. The variables studied were age, gender, histological subtype, tumor size, tumor grade, surgical margins, type of presentation of tumor (primary or recurrent) and presence of contiguous organ resection. The primary outcome measured was OS.

RESULTS

Eighty-five patients underwent resection of RPS with curative intent. Eight patients underwent adjuvant chemotherapy and 15 patients underwent radiotherapy. The median DFS was 21 months (range: 0-146) and median OS was 45 months (range: 1-233). On univariate analysis, resection margin (P = 0.04), tumor grade (P = 0.011) and type of presentation of tumor (P = 0.007) were found to significantly affect OS. Patients with tumor adherent to contiguous organs had a greater OS as compared to patients with tumor invasive into the contiguous organs (P = 0.02).

CONCLUSION

An aggressive surgical approach in primary and recurrent RPS is associated with good OS. Complete resection, with contiguous organ resection if necessary should be performed to achieve microscopically negative surgical margins to allow for long-term survival. However, tumor biology remains the main determinant for OS.

Significant benefits in survival by the use of surgery combined with radiotherapy for retroperitoneal soft tissue sarcoma

BACKGROUND

To report the effect of intraoperative electron beam radiotherapy (IOERT) and external beam radiotherapy (EBRT) in addition to surgery as well as to evaluate the role of resectable local recurrence for long-term prognosis.

METHODS

In 53 patients who underwent surgery for retroperitoneal soft tissue sarcoma (RSTS) from 2001 to 2014 prognostic and epidemiologic factors were reviewed retrospectively to analyze their impact on survival and recurrence.

RESULTS

Twenty three patients (50%) had surgery plus radiotherapy, 23 (50%) had surgery only. Histology showed 73.9% liposarcoma, 15.2% leiomyosarcoma and 6.5% pleomorphic undifferentiated sarcoma respectively. Low grade sarcoma were observed in 52.2%, high grade sarcoma in 47.8%. The latter showed a trend towards a decreased 5-year survival rate (p = 0.125). Margin status was: R0: 60.9%, R1: 23.9%, R2: 15.2%; leading to significant changes in 5-year survival rate (R0: 77.6%; R1: 70.0%; R2: 42.9%; p = 0.03). Age younger than 55 years significantly improved 5-year survival rate (p = 0.039). Patients receiving resection of multiple sarcoma recurrence showed an almost identical improved 5-year survival rate compared to patients without recurrence (no recurrence: 100.0%; single recurrence: 35.0%; multiple recurrence: 91.7%; p = 0.001). Surgery plus radiotherapy led to significantly improved survival (p = 0.04).

CONCLUSIONS

There is a significant benefit in terms of 5-year survival after surgery plus some form of radiotherapy and a good prognosis for patients when the recurrence from RSTS was resected. Age older than 55 years and incomplete resection lowered 5-year survival rate significantly.

Safety and efficacy of intensity-modulated radiotherapy in the management of spermatic cord sarcoma

PURPOSE

Spermatic cord sarcoma is a rare disease, which management remains controversial due to the lack of guidelines. The standard therapeutic approach is surgical: wide soft-tissue resection with radical inguinal orchidectomy, The diagnosis is made during the analysis of the specimen. The high rate of local recurrence indicates adjuvant radiotherapy of the tumor bed. The aim of this series is to determine the efficacy and safety of postoperative intensity-modulated radiotherapy for spermatic cord sarcomas.

PATIENTS AND METHODS

Our series included five consecutive cases of spermatic cord sarcoma treated between 2011 and 2014. The indications for radiotherapy were: R1 status after initial surgery, R1 status after wide en bloc resection and orchiectomy, high French federation of cancer centers (FNCLCC) grade, tumor size over 5cm, tumor resection during surgery.

RESULTS

Median age at diagnosis was 66years (range 46-84years). Median follow-up was 18months (range 6-28months). Four patients had repeat surgery after incomplete removal. All surgeries were orchidectomy with primary ligation of testicular vessels. One patient did not have an in sano margin after the second surgical procedure. The median tumor size was 60mm (range 30-150mm). No recurrence was observed during the follow-up.

CONCLUSION

No grade 4 toxicities were reported and the most frequent acute toxicity was dermatitis. No recurrence was reported after adjuvant intensity-modulated radiotherapy. The treatment is feasible and well tolerated and seems to provide encouraging results regarding locoregional control of the disease. Dynamic or rotational intensity-modulated radiotherapy is now recommended to decrease acute toxicities while improving the efficacy of this approach.

Prognostic factors in patients with recurrent or metastatic retroperitoneal leiomyosarcoma

AIMS

Factors that predict the prognosis of patients with recurrent or metastatic retroperitoneal leiomyosarcomas after treatment are uncertain.

MATERIALS & METHODS

Clinical and pathological data on 22 patients with retroperitoneal leiomyosarcomas who were treated by a multidisciplinary abdominal soft-tissue tumor group were analyzed retrospectively to identify prognostic factors for their progression-free survival (PFS).

RESULTS & CONCLUSION

The median PFS in the 22 patients was 9 months. Microvessel density in tumor tissues, which was evaluated via CD34 expression in 16 cases, and the presence of metastasis on admission were both found to be correlated with PFS in a Kaplan-Meier analysis, but not in a multivariate analysis. The multivariate analysis did, however, show that complete resection of tumors and the FNCLCC (Fédération Nationale des Centres de Lutte Contre Le Cancer) disease grade were independent factors predicting PFS.

Long-term morbidity after multivisceral resection for retroperitoneal sarcoma

Background

More than 60 per cent of patients treated surgically for primary retroperitoneal sarcoma survive for at least 5 years. Extended surgical resection has been proposed for primary disease, but long-term morbidity data are lacking. A cross-sectional study was conducted to assess the long-term morbidity of patients undergoing surgery for retroperitoneal sarcoma.

Methods

Patients operated on between January 2002 and December 2011 were eligible for the study. Long-term morbidity was evaluated based on a semistructured clinical interview. Lower limb function was assessed by means of the Lower Extremity Functional Scale (LEFS), a self-report questionnaire with a total score ranging from 0 (low functioning) to 80 (high functioning). Pain was investigated by means of the Brief Pain Inventory – Short Form, with pain intensity scores reported on a scale from 0 (no pain) to 10 (worst pain).

Results

Some 243 patients underwent surgery, and 101 of 160 patients who were alive at the time of the investigation responded to the study invitation letter. Finally, 95 patients were enrolled in the study. Sensory impairment of the limbs was reported in 72 patients (76 per cent). The median LEFS score was 60 (i.q.r. 43–73). Mean scores for the pain intensity items varied from 1·23 to 2·68. In multivariable analysis, there was no difference in median levels of creatinine at survey between patients who did or did not undergo nephrectomy (difference between median values 13 (95 per cent c.i. −4 to 30) µmol/l; P = 0·170).

Conclusion

Severe chronic pain and lower limb motor impairment after multivisceral resection for retroperitoneal sarcomas are rare. Long-term renal function is not significantly impaired when nephrectomy is performed.

Combined Modality Management of Retroperitoneal Sarcomas: A Single-Institution Series of 121 Patients

PURPOSE

The purpose of this study was to investigate local control, survival outcomes, and complication rates of patients treated with aggressive surgery and radiation therapy (RT) for retroperitoneal sarcomas (RPS).

METHODS AND MATERIALS

We reviewed the medical records of 121 consecutive patients treated for RPS with surgery and RT between 1965 and 2012. The most common histology was liposarcoma (n = 42; 35%). The median follow-up was 100 months (range: 20-467 months). Eighty-six patients (71%) were treated for initial presentation of RPS, and 35 patients (29%) presented with and were treated for RPS recurrence. RT was preoperative in 88 patients (73%; median dose: 50.4 Gy) and postoperative in 33 patients (27%; median dose: 55 Gy).

RESULTS

Five-year local control and overall survival rates were 56% and 57%, respectively. Two factors were associated with higher risk of any intra-abdominal recurrence at 5 years: positive or uncertain margins (58% vs 30% for negative margins, P < .001; hazard ratio [HR]: 2.7; 95% confidence interval [CI]: 1.6-4.8) and disease recurrence after previous resection (76% vs 31% for de novo RPS, P < .001; HR: 4.4; 95% CI: 2.5-7.5). The 10-year complication rate was 5%, and RT-related complications were associated with postoperative RT (P < .001) and RT dose of ≥ 60 Gy (P < .001).

CONCLUSIONS

Intra-abdominal RPS recurrence continues to be a significant challenge despite the use of aggressive surgery and radiation therapy. Given the complications associated with postoperative radiation therapy, we recommend that preoperative radiation therapy is the preferred strategy when combined modality therapy is recommended.

Personalizing surgical margins in retroperitoneal sarcomas

Retroperitoneal sarcomas are a group of diseases that behave differently from one another. Well-differentiated liposarcomas have an indolent biology but show a tendency to recur locally even years after primary resection. Dedifferentiated liposarcomas are characterized by a very high local recurrence risk, while the metastatic risk mainly depends on the histological characteristics of the dedifferentiated component. In leiomyosarcomas, hematogenous spread informs prognosis while local recurrences are far less common. Surgery is the cornerstone of treatment of all retroperitoneal sarcoma subtypes and its quality is the only treatment-related factor able to improve the oncological outcome. A frontline extended surgical approach is all the more critical in subtypes in which local control directly impacts prognosis.

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.

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.

Current concepts in multimodality therapy for retroperitoneal sarcoma

Radical surgical resection currently represents the most effective therapy for patients with retroperitoneal sarcoma. Unfortunately, margin-negative resection often mandates extirpation of multiple retroperitoneal viscera, and such operations are nonetheless fraught with high rates of locoregional recurrence. In an attempt to improve local control and ultimately survival, adjuvant strategies of radiation and chemotherapy have been increasingly employed, with promising results. To date, however, the rarity of the disease has limited large, prospective studies investigating the efficacy of these adjuvant modalities. In this article, we review the current literature pertaining to the diagnosis, staging and treatment of retroperitoneal sarcoma and demonstrate the critical need for future large, multi-institutional studies to advance our knowledge of this uncommon disease.

Management of recurrent retroperitoneal sarcoma

Approximately 15% of soft tissue sarcomas are retroperitoneal. The occult location and anatomic complexity results in local recurrences in the majority of patients. Predictors of recurrence include histological subtype, completeness of resection, and the hospital case volume. The most significant predictor of outcome following local recurrence is the resectability of the recurrent disease. An understanding of the implication of tumor biology on outcomes is essential in determining optimal management for patients with recurrent retroperitoneal sarcoma.

Retroperitoneal sarcomas- a challenging problem

Retroperitoneal sarcomas are relatively rare tumours and usually present in a locally advanced stage. Liposarcoma is the most common histopathology. If operable, surgery is the treatment of choice. The role of adjuvant chemotherapy or radiotherapy is not yet defined. Advanced cases are treated by chemotherapy. The prognosis is poor in patients with positive resection margins, high-grade tumours and recurrent tumours.

Complete and safe resection of challenging retroperitoneal tumors: anticipation of multi-organ and major vascular resection and use of adjunct procedures

BACKGROUND

Retroperitoneal tumors are often massive and can involve adjacent organs and/or vital structures, making them difficult to resect. Completeness of resection is within the surgeon's control and critical for long-term survival, particularly for malignant disease. Few studies directly address strategies for complete and safe resection of challenging retroperitoneal tumors.

METHODS

Fifty-six patients representing 63 cases of primary or recurrent retroperitoneal tumor resection between 2004-2009 were identified and a retrospective chart review was performed. Rates of complete resection, use of adjunct procedures, and perioperative complications were recorded.

RESULTS

In 95% of cases, complete resection was achieved. Fifty-eight percent of these cases required en bloc multi-organ resection, and 8% required major vascular resection. Complete resection rates were higher for primary versus recurrent disease. Adjunct procedures (ureteral stents, femoral nerve monitoring, posterior laminotomy, etc.) were used in 54% of cases. Major postoperative complications occurred in 16% of cases, and one patient died (2% mortality).

CONCLUSIONS

Complete resection of challenging retroperitoneal tumors is feasible and can be done safely with important pre- and intraoperative considerations in mind.

Significance of microscopic margin status in completely resected retroperitoneal sarcoma

PURPOSE

We determined whether microscopic margin status is an independent prognosticator in patients who underwent complete resection of retroperitoneal sarcoma.

MATERIALS AND METHODS

A total of 99 patients with a median age of 55.4 years (range 26.0 to 81.9) underwent complete surgical resection for primary (79) or recurrent (20) retroperitoneal sarcoma between September 1990 and January 2010. Median followup was 36.0 months (range 1.0 to 221.1).

RESULTS

Microscopic involvement of the margins was detected in 24 patients and local recurrence developed in 69 (69.7%). Univariate analysis showed that pain, recurrent disease and higher Fédération Nationale des Centres de Lutte Contre le Cancer grade were associated with an increased risk of local recurrence. On multivariate Cox analysis presenting symptoms and grade were significantly associated with local recurrence-free survival, including pain vs other symptoms (HR 1.7, p = 0.035) and grade 3 vs 1 (HR 2.4, p = 0.028). A total of 25 patients (25.3%) died of retroperitoneal sarcoma. Histological subtype, grade and tumor margin status were prognostic for disease specific survival. Cox regression analysis revealed that certain factors were significantly associated with disease specific survival, including other sarcomas vs liposarcoma (HR 2.8, p = 0.030) and positive vs negative margins (HR 3.4, p = 0.005).

CONCLUSIONS

Although complete surgical resection is possible in patients with retroperitoneal sarcoma, the procedure is associated with a high recurrence rate even in patients with negative margins. Microscopically clear margins reliably predict disease specific survival but not local control.

Intraabdominal and retroperitoneal soft-tissue sarcomas--outcome of surgical treatment in primary and recurrent tumors

BACKGROUND

Surgery is the only curative treatment for intraabdominal and retroperitoneal sarcoma (IaRS). Little is known about how to treat patients with recurrence. We here report the outcome in primary and recurrent sarcoma treated at the Sarcoma Center in Aarhus, Denmark.

METHODS

All patients evaluated for IaRS from June 1998 to May 2008 were enrolled and data on symptoms, signs, means of diagnosis, extent of surgery, perioperative complications, mortality and long time survival were registered. Primary and first-recurrence sarcomas were analyzed separately.

RESULTS

Sixty-five of 73 primary and 22 of 28 first-recurrence IaRS had surgery. Fifty-three (82%) and 11 (50%) patients achieved radical R0 resection. Age and radicality of surgery were independent predictors of death, while recurrence of sarcoma was not. Perioperative mortality was 2.3%. 5-year survival was 70.2% for primary and 51.8% for first-recurrent sarcomas. However, patients with radical surgery had 5-year survival of over 70% in both the primary and recurrent group.

CONCLUSIONS

The radicality of surgery is the most important prognostic factor. Patients with recurrence have an equally good prognosis as those with primary sarcoma if radicality is achieved and such surgery should not be considered only as a palliative effort.

Surgery combined with brachytherapy in patients with retroperitoneal sarcomas

Purpose

The primary aim of this work was to analyze feasibility of combined treatment of retroperitoneal sarcomas (RS): surgery (S) and intraoperative brachytherapy (IOBRT). The secondary aim was to analyze results and complications after this treatment.

Material and methods

84 patients with retroperitoneal sarcomas were qualified for combined treatment (S and IOBRT) between June 1998 and September 2006. 65 of the patients (77.4%) had local recurrences. Sarcomas with intermediate and high grade of histological malignancy (G2, G3 – 76.2%) were the most frequent within the all surgically treated patients. Resection ability (R0/R1) in analyzed group of patients was estimated as 85% (74 cases). After intraoperative evaluation, 57 (67.8%) patients were qualified for IOBRT. Since 2000, in 34 patients (60%) an adjuvant postoperative external beam radiation therapy (EBRT) in dose of 50 Gy was applied. Median follow-up of the surviving patients was 40 months.

Results

On the basis of the univariate analysis, relevant aspects negatively influencing overall survival rate within the RS group treated with IOBRT were as follows: surgery of sarcoma recurrence (p = 0.002), higher grade of histological malignancy (p = 0.05), histological type different than liposarcoma (p = 0.05) as well as no adjuvant EBRT (p = 0.05). On the basis of multivariate analysis one can ascertain that relevant factors negatively influencing LRFS in RS patients treated with IOBRT were: surgery due to recurrence of sarcoma (p = 0.008) and lack of EBRT (p = 0.01).

Conclusions

Combined treatment (surgery and brachytherapy) was possible to be carried out on 68% of RS patients. The overall number of complications was quite high, however acceptable, taking into consideration the application of extensive, multi-organ treatments in case of sarcoma recurrences in this localization. The results suggest that the method of treatment will improve the final outcome when most of patients will be qualified for treatment of primary sarcomas in experienced centre.

Predictors of survival after resection of retroperitoneal sarcoma: a population-based analysis and critical appraisal of the AJCC staging system

OBJECTIVE

To identify predictors of survival after resection of retroperitoneal sarcoma (RPS) and to evaluate the performance of the American Joint Committee on Cancer (AJCC) staging system for RPS.

SUMMARY BACKGROUND DATA

Previous studies of survival after RPS resection are restricted to at most several institutions, yet the current AJCC staging system for RPS is based entirely on these relatively small studies.

METHODS

Patients undergoing resection of primary RPS from 1988 to 2005 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Cox proportional hazards models were used to analyze survival and evaluate AJCC staging.

RESULTS

In 1365 patient undergoing resection of primary RPS, the most prevalent histologies were liposarcoma (50%), leiomyosarcoma (26%), and malignant fibrous histiocytoma (11%). Median, 5-year, and 10-year survival after resection were 55 months, 47%, and 27%. Histological subtype (P < 0.001), histological grade (grade 3-4 vs. grade 1; HR, 2.42; P < 0.001), and tumor invasion of adjacent structures (HR, 1.37; P < 0.001) were associated with survival on multivariable analysis. However, tumor size had no prognostic value. Consequently, the AJCC T classification system demonstrated poor discriminatory ability (c = 0.50). The AJCC stage grouping system demonstrated moderate discriminatory ability (c = 0.66) but performed no better than a much simpler system that omits information on tumor size and lymph node metastasis (c = 0.67).

CONCLUSIONS

Indicators of tumor aggressiveness (histological grade and invasion of adjacent structures) as well as histological subtype predict survival after RPS resection. Tumor size, however, does not impact survival. The AJCC staging system for RPS is in need of revision.

The value of surgery for retroperitoneal sarcoma

Introduction. Retroperitoneal sarcomas are uncommon large malignant tumors. Methods. Forty-one consecutive patients with localized retroperitoneal sarcoma were retrospectively studied. Results. Median age was 58 years (range 20–91 years). Median tumor size was 17.5 cm (range 4–41 cm). Only 2 tumors were <5 cm. Most were liposarcoma (44%) and high-grade (59%). 59% were stage 3 and the rest was stage 1. Median followup was 10 months (range 1–106 months). Thirty-eight patients had an initial complete resection; 15 (37%) developed recurrent sarcoma and 12 (80%) had a second complete resection. Patients with an initial complete resection had a 5-year survival of 46%. For all patients, tumor grade affected overall survival (P = .006). Complete surgical resection improved overall survival for high-grade tumors (P = .03). Conclusions. Tumor grade/stage and complete surgical resection for high-grade tumors are important prognostic variables. Radiation therapy or chemotherapy had no significant impact on overall or recurrence-free survival. Complete surgical resection is the treatment of choice for patients with initial and locally recurrent retroperitoneal sarcoma.

Postoperative nomogram for survival of patients with retroperitoneal sarcoma treated with curative intent

BACKGROUND

Current American Joint Committee on Cancer retroperitoneal sarcoma (RPS) staging is not representative of patients with RPS specifically and has limited discriminative power. Our objective was to develop a RPS disease-specific nomogram capable of stratifying patients based on probability of overall survival (OS) after resection.

PATIENTS AND METHODS

In all, 1118 RPS patients were evaluated at our institution (1996-2006). Patients with resectable, nonmetastatic disease were selected (n = 343) and baseline, treatment and outcome variables were retrieved. A nomogram was created and its performance was evaluated by calculating its discrimination (concordance index) and calibration and by subsequent internal validation.

RESULTS

Median follow-up and OS were 50 and 59 months, respectively. Independent predictors of OS were included in the nomogram: age (> or = 65), tumor size (> or = 15 cm), type of presentation (primary versus recurrent), multifocality, completeness of resection and histology. The concordance index was 0.73 [95% confidence interval (CI) 0.71-0.75] and the calibration was excellent, with all observed outcomes within the 95% CI of each predicted survival probability.

CONCLUSIONS

A RPS-specific postoperative nomogram was developed. It improves RPS staging by allowing a more dynamic and robust disease-specific risk stratification. This prognostic tool can help in patient counseling and for selection of high-risk patients that may benefit from adjuvant therapies or inclusion into clinical trials.

The role of surgical margin status in retroperitoneal sarcoma

Retroperitoneal sarcomas (RPS) represent approximately 15% of all soft tissue sarcomas (STS). Clinical and prognostic features as well as oncologic outcomes are well known in this group of patients. Post-operative margin status specifically, is a major predictor of local and distant recurrence and survival. The purpose of this review is to define complete resection as it applies to RPS and evaluate its effect on future outcomes in these patients.