Current concepts and future perspectives in retroperitoneal soft-tissue sarcoma management

Soft Tissue Sarcoma, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Soft tissue sarcomas (STS) are rare malignancies of mesenchymal cell origin that display a heterogenous mix of clinical and pathologic characteristics. STS can develop from fat, muscle, nerves, blood vessels, and other connective tissues. The evaluation and treatment of patients with STS requires a multidisciplinary team with demonstrated expertise in the management of these tumors. The complete NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Soft Tissue Sarcoma provide recommendations for the diagnosis, evaluation, and treatment of extremity/superficial trunk/head and neck STS, as well as retroperitoneal/intra-abdominal STS, desmoid tumors, and rhabdomyosarcoma. This portion of the NCCN Guidelines discusses general principles for the diagnosis and treatment of retroperitoneal/intra-abdominal STS, outlines treatment recommendations, and reviews the evidence to support the guidelines recommendations.

Case Report: Retroperitoneal Sarcoma in Six Operations: Our Experience in Operative Management of Blood Vessels

Here we introduce a case of retroperitoneal liposarcoma, which is characterized by repeated recurrences after surgery, and has undergone a total of 6 operations. The diameter of the tumor was about 26 cm at the time of the patient's diagnosis. The imaging examination revealed that the surrounding organs and blood vessels were invaded, which brought great challenges to radical resection. The postoperative pathology of the patient’s first operation was dedifferentiated liposarcoma, and some areas showed myxofibrosarcoma differentiation. With the recurrence of sarcoma, myxofibrosarcoma dedifferentiated into rhabdomyosarcoma, and malignant fibrous histiocytoma appeared in some areas. How to treat this type of patient after recurrence? How to deal with blood vessels wrapped by sarcoma during surgery? The medical community has not yet reached the same conclusion. We describe the process of treating the patient and the experience of dealing with blood vessels during surgery.

The Role of Surgical Expertise and Surgical Access in Retroperitoneal Sarcoma Resection – A Retrospective Study

Background

Retroperitoneal sarcoma (RPS) is a rare disease often requiring multi-visceral and wide margin resections for which a resection in a sarcoma center is advised. Midline incision seems to be the access of choice. However, up to now there is no evidence for the best surgical access. This study aimed to analyze the oncological outcome according to the surgical expertise and also the incision used for the resection.

Methods

All patients treated for RPS between 2007 and 2018 at the Department of Visceral Surgery and Medicine of the University Hospital Bern and receiving a RPS resection in curative intent were included. Patient- and treatment specific factors as well as local recurrence-free, disease-free and overall survival were analyzed in correlation to the hospital type where the resection occurred.

Results

Thirty-five patients were treated for RPS at our center. The majority received their primary RPS resection at a sarcoma center (SC = 23) the rest of the resection were performed in a non-sarcoma center (non-SC = 12). Median tumor size was 24 cm. Resections were performed via a midline laparotomy (ML = 31) or flank incision (FI = 4). All patients with a primary FI (n = 4) were operated in a non-SC (p = 0.003). No patient operated at a non-SC received a multivisceral resection (p = 0.004). Incomplete resection (R2) was observed more often when resection was done in a non-SC (p = 0.013). Resection at a non-SC was significantly associated with worse recurrence-free survival and disease-free survival after R0/1 resection (2 vs 17 months; Log Rank p-value = 0.02 respectively 2 vs 15 months; Log Rank p-value < 0.001).

Conclusions

Resection at a non-SC is associated with more incomplete resection and worse outcome in RPS surgery. Inadequate access, such as FI, may prevent complete resection and multivisceral resection if indicated and demonstrates the importance of surgical expertise in the outcome of RPS resection.

A nationwide cohort study on treatment and survival in patients with malignant peripheral nerve sheath tumours

BACKGROUND

Despite curative intents of treatment in localized malignant peripheral nerve sheath tumours (MPNSTs), prognosis remains poor. This study investigated survival and prognostic factors for overall survival in non-retroperitoneal and retroperitoneal MPNSTs in the Netherlands.

METHODS

Data were obtained from the Netherlands Cancer Registry and the Dutch Pathology Database. All primary MPNSTs were collected. Paediatric cases (age ≤18 years) and synchronous metastases were excluded from analyses. Separate Cox proportional hazard models were made for retroperitoneal and non-retroperitoneal MPNSTs.

RESULTS

A total of 629 localized adult MPNSTs (35 retroperitoneal cases, 5.5%) were included for analysis. In surgically resected patients (88.1%), radiotherapy and chemotherapy were administered in 44.2% and 6.7%, respectively. In retroperitoneal cases, significantly less radiotherapy and more chemotherapy were applied. In non-retroperitoneal MPNSTs, older age (60+), presence of NF1, size >5 cm, and deep-seated tumours were independently associated with worse survival. In retroperitoneal MPNSTs, male sex and age of 60+ years were independently associated with worse survival. Survival of R1 and that of R0 resections were similar for any location, whereas R2 resections were associated with worse outcomes. Radiotherapy and chemotherapy administrations were not associated with survival.

CONCLUSION

In localized MPNSTs, risk stratification for survival can be done using several patient- and tumour-specific characteristics. Resectability is the most important predictor for survival in MPNSTs. No difference is present between R1 and R0 resections in both retroperitoneal and non-retroperitoneal MPNSTs. The added value of radiotherapy and chemotherapy is unclear.

Neoadjuvant and adjuvant strategies in retroperitoneal sarcoma

Extended surgery remains the mainstay of treatment in retroperitoneal sarcoma, although conflicting data exist on the benefit of neoadjuvant and adjuvant therapies, particularly with regard to tumour grade and histological type. Experience of radiotherapy and chemotherapy in extremity soft tissue sarcoma can inform treatment strategies, however these data cannot be universally extrapolated to the retroperitoneum where disease biology and anatomical considerations are different. The present review sets a historical context before discussing recent evidence and on-going multi-centre trials in retroperitoneal sarcoma. Promising data on histologically- and molecularly-targeted chemotherapy are discussed and the need for centralisation of retroperitoneal sarcoma services in order to facilitate large international collaborative trials is emphasised.

Can Abdominal Computed Tomography Imaging Help Accurately Identify a Dedifferentiated Component in a Well-Differentiated Liposarcoma?

PURPOSE

To assess the ability of computed tomography (CT) to differentiate an atypical lipomatous tumor/well-differentiated liposarcoma (WDLPS) from a WDLPS with a dedifferentiated component (DDLPS) within it.

MATERIALS AND METHODS

Forty-nine untreated patients with abdominal atypical lipomatous tumors/well-differentiated liposarcomas who had undergone contrast-enhanced CT were identified using an institutional database. Three radiologists who were blinded to the pathology findings evaluated all the images independently to determine whether a dedifferentiated component was present within the WDLPS. The CT images were evaluated for fat content (≤25% or >25%); presence of ground-glass density, enhancing and/or necrotic nodules; presence of a capsule surrounding the mass; septations; and presence and pattern of calcifications. A multivariate logistic regression model with generalized estimating equations was used to correlate imaging features with pathology findings. Kappa statistics were calculated to assess agreement between the three radiologists.

RESULTS

On the basis of pathological findings, 12 patients had been diagnosed with DDLPS within a WDLPS and 37 had been diagnosed with WDLPS. The presence of an enhancing or a centrally necrotic nodule within the atypical lipomatous tumor was associated with dedifferentiated liposarcoma (P = 0.02 and P = 0.0003, respectively). The three readers showed almost perfect agreement in overall diagnosis (κ r = 0.83; 95% confidence interval, 0.67-0.99).

CONCLUSIONS

An enhancing or centrally necrotic nodule may be indicative of a dedifferentiated component in well-differentiated liposarcoma. Ground-glass density nodules may not be indicative of dedifferentiation.

(Neo)adjuvant treatment in localised soft tissue sarcoma: The unsolved affair

Soft tissue sarcomas (STS) are rare and heterogeneous tumours. A correct definition of STS is imperative from the very beginning of disease management, to guide the diagnostic and imaging work-up, and help to establish the prognosis on which the therapeutic strategy will be based. Over the last few years, many efforts have been made to identify characteristics that could predict disease behaviour and to enrich the therapeutic armamentarium against the advanced disease, that is still characterised by poor prognosis. Surgery remains the milestone of treatment for localised STS, whereas many uncertainties regarding the role of adjuvant and neoadjuvant treatment persist. Some controlled evidence is available, but often conflicting and insufficient to make chemotherapy (CT) a standard practice and, currently, a common and shared strategy does not exist. The biggest question concerns the prospective identification of the subgroup of patients who would benefit the most from (neo)adjuvant therapies. In light of the growing understanding of different biologies and sensitivities of the various sarcoma subtypes, the value of histology in the selection of peri-operative treatments is one of the most intriguing topics under discussion. In this perspective, a new generation of neoadjuvant trials have been planned and are currently ongoing. The aim of this review was to rekindle interest in the long-standing topic of (neo)adjuvant CT in localised STS, providing an update on its role in sarcomas' management and highlighting future directions and consequential factors needed to further improve outcomes in this disease.

Percutaneous computed tomography-guided cryoablation for recurrent retroperitoneal soft tissue sarcoma: a study of safety and efficacy

AIMS

To evaluate the use of computed tomography image-guided percutaneous cryoablation for recurrent retroperitoneal soft tissue sarcomas (RPSs).

RESULTS

Adverse events were limited to grades 1 and 2, included fever (n = 19), local pain (n = 11), emesis (n = 10), frostbite (n = 6), and nerve injury (n = 1). Fever was more frequent in the large tumor group (15.8%) than in small tumor group (1.9%) (P = 0.008). Median PFS and OS were 37.0 ± 7.7 months (range, 4-39 months) and 43.0 ± 5.9 months (range, 6-54 months), respectively. PFS and OS were significantly longer in the small tumor group than in the large tumor group (P = 0.011 and P = 0.015, respectively), but the response rate (82.7% vs. 72.8%, P = 0.240) did not differ significantly. On univariate analysis, tumor size, tumor invasion grade, and distant metastasis were significant prognostic factors for PFS and OS. On multivariate analysis, a tumor size ≥10 cm was an independent negative prognostic factor for PFS and OS after cryoablation (HR: 3.98, 95% CI: 1.27-12.50, P = 0.018 and HR: 4.33, 95% CI: 1.41-13.26, P = 0.010, respectively).

MATERIALS AND METHODS

Data from 72 patients with recurrent RPSs who underwent percutaneous cryoablation were reviewed retrospectively. The prognostic factors for progression-free survival (PFS), overall survival (OS), and efficacy based on mRECIST criteria were analysis. Adverse events were compared according to tumor size (<10 and ≥10 cm).

CONCLUSION

Minimally invasive percutaneous cryoablation was safe and efficacious for recurrent RPSs.

Practical Issues for Retroperitoneal Sarcoma

Background

Retroperitoneal sarcoma is rare. Using initial specimens on biopsy, a definitive diagnosis of histological subtypes is ideal but not always achievable.

Methods

A retrospective institutional review was performed for all cases of adult retroperitoneal sarcoma from 1996 to 2015. A review of the literature was also performed related to the distribution of retroperitoneal sarcoma subtypes. A meta-analysis was performed.

Results

Liposarcoma is the most common subtype (45%), followed by leiomyosarcoma (21%), not otherwise specified (8%), and undifferentiated pleomorphic sarcoma (6%) by literature review. Data from Moffitt Cancer Center demonstrate the same general distribution for subtypes of retroperitoneal sarcoma. A pathology-based algorithm for the diagnosis of retroperitoneal sarcoma is illustrated, and common pitfalls in the pathology of retroperitoneal sarcoma are discussed.

Conclusions

An informative diagnosis of retroperitoneal sarcoma via specimens on biopsy is achievable and meaningful to guide effective therapy. A practical and multidisciplinary algorithm focused on the histopathology is helpful for the management of retroperitoneal sarcoma.

Histology-based Classification Predicts Pattern of Recurrence and Improves Risk Stratification in Primary Retroperitoneal Sarcoma

OBJECTIVE

To determine the prognostic significance of histologic type/subtype in a large series of patients with primary resected retroperitoneal sarcoma.

BACKGROUND

The histologic diversity and rarity of retroperitoneal sarcoma has hampered the ability to predict patient outcome.

METHODS

From a single-institution, prospective database, 675 patients treated surgically for primary, nonmetastatic retroperitoneal sarcoma during 1982 to 2010 were identified and histologic type/subtype was reviewed. Clinicopathologic variables were analyzed for association with disease-specific death (DSD), local recurrence (LR), and distant recurrence (DR).

RESULTS

Median follow-up for survivors was 7.5 years. The predominant histologies were well-differentiated liposarcoma, dedifferentiated liposarcoma, and leiomyosarcoma. Five-year cumulative incidence of DSD was 31%, and factors independently associated with DSD were R2 resection, resection of 3 or more contiguous organs, and histologic type. Five-year cumulative incidence for LR was 39% and for DR was 24%. R1 resection, age, tumor size, and histologic type were independently associated with LR; size, resection of 3 or more organs, and histologic type were independently associated with DR. Liposarcoma and leiomyosarcoma were associated with late recurrence and DSD (as long as 15 years from diagnosis). For solitary fibrous tumor, LR was uncommon (<10%), but early distant recurrence was common (36% at 5 years). Nomograms were developed to predict DSD, LR, and DR.

CONCLUSIONS

Histologic type/subtype is the most important independent predictor of DSD, LR, and DR in primary retroperitoneal sarcoma. Histology predicts the pattern and incidence of LR and DR and will aid in more accurate patient counseling and selection of patients for adjuvant therapy trials.

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.

Modified simultaneous integrated boost radiotherapy for large retroperitoneal malignant tumor: A case report

The current study reports the case of a large retroperitoneal tumor treated with modified simultaneous integrated boost (SIB) radiotherapy. A 45-year-old female presented to the emergency department complaining of left abdominal pain and fever. A computed tomography scan detected a retroperitoneal tumor of 12×16×16 cm, and a biopsy revealed a poorly-differentiated adenocarcinoma. The patient was diagnosed with a large adenocarcinoma originating from the left ureter, with no distant metastasis. Due to the patient's poor physical condition, surgery was not recommended, and the patient was referred to the Department of Radiation Oncology (Yamagata University Hospital, Yamagata, Japan). Modified SIB radiotherapy was administered following the acquisition of written consent from the patient. The total irradiation dose to the center of the tumor and to the surrounding healthy tissue was ∼96 Gy/33 fractions and <60 Gy/33 fractions, respectively. At the end of the radiotherapeutic course, the tumor volume was reduced by ≥80%, and the residual tumor was surgically resected. As a result of the resection, a complete pathological response was confirmed; the patient has been recurrence-free for >3 years with no complications. Modified SIB radiotherapy may be safely administered, with favorable outcomes. Complete recovery can be achieved with this technique, even in a patient with a large radioresistant tumor.

Delayed primary excision with subsequent modification of radiotherapy dose for intermediate-risk rhabdomyosarcoma: a report from the Children's Oncology Group Soft Tissue Sarcoma Committee

The majority of intermediate-risk rhabdomyosarcoma (RMS) patients have gross residual disease (Group III) after their first operative procedure. It is currently not known if local control rates can be maintained when, following induction chemotherapy, the radiation therapy (RT) dose is decreased after a delayed primary excision (DPE). To answer this question we evaluated patients enrolled on COG D9803 (1999-2005) who had Group III tumors of the bladder dome, extremity or trunk (thorax, abdomen and pelvis) were candidates for DPE at Week 12 if the primary tumor appeared resectable. RT dose was then adjusted by the completeness of DPE: no evidence of disease 36 Gy, microscopic residual 41.4 Gy and gross residual disease (GRD) 50.4 Gy. A total of 161 Group III patients were evaluated (24 bladder dome, 63 extremity and 74 trunk). Seventy-three patients (45%) underwent DPE which achieved removal of all gross disease in 61 (84%) who were then eligible for reduced RT dose (43/73 received 36 Gy, 19/73 received 41.4 Gy). The local 5-year failure rate (0% for bladder dome, 7% for extremity and 20% for trunk) was similar to IRS-IV, which did not encourage DPE and did not allow for DPE adapted RT dose reduction. In conclusion, DPE was performed in 45% of Group III RMS patients with tumors at select anatomic sites (bladder dome, extremity and trunk) and 84% of those who had DPE were eligible for RT dose reduction. Local control outcomes were similar to historic results with RT alone.

Adjuvant radiotherapy in retroperitoneal sarcomas. A Scandinavian Sarcoma Group study of 97 patients

BACKGROUND

Currently there is no consensus on the use of adjuvant radiotherapy (RT) in retroperitoneal sarcoma (RPS). We have analysed clinical outcomes in patients with localised RPS treated at two Scandinavian Sarcoma Group (SSG) centres: Haukeland University Hospital (HUH), Bergen, Norway and Skåne University Hospital (SUH), Lund, Sweden to clarify the effects of adjuvant RT on local control and overall survival (OS).

MATERIAL AND METHODS

Local databases and registers at HUH and SUH as well as the SSG central register were used to identify RPS patients. Patients with localised RPS who underwent surgery in Bergen between 1988 and 2009 and in Lund from 1998 to 2009 were included. Medical records were examined for clinical data, tumour characteristics, treatment factors and follow-up status. Archived tumour sections and tumour tissue were reviewed, and when necessary, restained and reclassified. Cox regression was used to analyse the association of potential prognostic factors with local recurrence-free survival (LRFS), metastasis-free survival (MFS) and OS.

RESULTS

The study included 97 patients: 52 from Norway and 45 from Sweden. The proportion of high-grade tumours was 73%. The five-year LRFS, MFS and OS were 55%, 59% and 60%, respectively. RT was significantly associated with improved local control resulting in a five-year LRFS of 77% compared with 39% without (p < 0.001). Furthermore, five-year OS was 71% in the RT group in contrast to 52% with surgery alone (p = 0.019). In the adjusted analysis RT proved to be a significant factor also for MFS (HR = 0.42, 95% CI 0.20-0.88, p = 0.021). In addition, high-grade malignancy, large tumour and positive surgical margin were risk factors for local recurrence. High malignancy grade was the only significant adverse prognostic factor for metastasis. High age and high-grade malignancy were negative prognostic factors for OS.

CONCLUSION

Adjuvant RT was significantly associated with an improved five-year LRFS and OS.

Challenging dedifferentiated liposarcoma identified by MDM2-amplification, a report of two cases

Background

Liposarcoma is the most frequent soft tissue sarcoma. Well differentiated liposarcoma may progress into dedifferentiated liposarcoma with pleomorphic histology. A minority additionally features myogenic, osteo- or chondrosarcomatous heterologous differentiation. Genomic amplification of the Mouse double minute 2 homolog (MDM2) locus is characteristic for well differentiated and dedifferentiated liposarcomas. Detection of MDM2 amplification may supplement histopathology and aid to distinguish liposarcoma from other soft tissue neoplasia.

Case presentation

Here we present two cases of dedifferentiated liposarcoma with challenging presentation. Case 1 features a myogenic component. As the tumour infiltrated the abdominal muscles and showed immunohistochemical expression of myogenic proteins, rhabdomyosarcoma had to be ruled out. Case 2 has an osteosarcomatous component resembling extraosseous osteosarcoma. The MDM2 status was determined in both cases and helped making the correct diagnosis. Overexpression of MDM2 and co-overexpression of Cyclin-dependent kinase 4 is demonstrated by immunohistochemistry. The underlying MDM2 amplification is shown by fluorescence in situ hybridisation. Since low grade osteosarcoma may also harbour MDM2 amplification it is emphasised that the amplification has to be present in the lipomatous parts of the tumour to distinguish liposarcoma from extraosseous osteosarcoma.

Conclusions

The two cases exemplify challenges in the diagnoses of dedifferentiated liposarcoma. Liposarcoma often has pleomorphic histology and additionally may feature heterologous components that mimic other soft tissue neoplasms. Amplification of MDM2 is characteristic for well differentiated and dedifferentiated liposarcomas. Determination of the MDM2 status by in situ hybridisation may assist histopathology and help to rule out differential diagnoses.

Outcome prediction in primary resected retroperitoneal soft tissue sarcoma: histology-specific overall survival and disease-free survival nomograms built on major sarcoma center data sets

PURPOSE

Integration of numerous prognostic variables not included in the conventional staging of retroperitoneal soft tissue sarcomas (RPS) is essential in providing effective treatment. The purpose of this study was to build a specific nomogram for predicting postoperative overall survival (OS) and disease-free survival (DFS) in patients with primary RPS.

PATIENTS AND METHODS

Data registered in three institutional prospective sarcoma databases were used. We included patients with primary localized RPS resected between 1999 and 2009. Univariate (Kaplan and Meier plots) and multivariate (Cox model) analyses were carried out. The a priori chosen prognostic covariates were age, tumor size, grade, histologic subtype, multifocality, quality of surgery, and radiation therapy. External validation was performed by applying the nomograms to the patients of an external cohort. The model's discriminative ability was estimated by means of the bootstrap-corrected Harrell C statistic.

RESULTS

In all, 523 patients were identified at the three institutions (developing set). At a median follow-up of 45 months (interquartile range, 22 to 72 months), 171 deaths were recorded. Five- and 7-year OS rates were 56.8% (95% CI, 51.4% to 62.6%) and 46.7% (95% CI, 39.9% to 54.6%. Two hundred twenty-one patients had disease recurrence. Five- and 7-year DFS rates were 39.4% (95% CI, 34.5% to 45.0%) and 35.7% (95% CI, 30.3% to 42.1%). The validation set consisted of 135 patients who were identified at the fourth institution for external validation. The bootstrap-corrected Harrell C statistics for OS and DFS were 0.74 and 0.71 in the developing set and 0.68 and 0.69 in the validating set.

CONCLUSION

These nomograms accurately predict OS and DFS. They should be used for patient counseling in clinical practice and stratification in clinical trials.

Primary pancreatic pleomorphic leiomyosarcoma

Primary pancreatic leiomyosarcoma is a rare mesenchymal tumour that is believed to arise from the walls of the pancreatic blood vessels or the pancreatic duct. A 56-year-old female was referred with epigastric pain and abdominal mass. Preoperative computed tomography showed a large soft tissue mass in the pancreatic body and tail. Fine needle aspiration biopsy indicated a spindle cell type tumour. The patient received distal pancreatectomy with no adjuvant treatment. Histology revealed a pleomorphic spindle cell neoplasm with an immunoprofile suggestive of smooth muscle origin. The absence of other lesions in the body was consistent with the diagnosis of primary pleomorphic leiomyosarcoma. The patient was well and tumour-free 14 months after surgery. Detailed immunohistochemical analyses are necessary in the diagnosis of this highly malignant tumour. Radical resection offers the only chance of long-term survival.

Management of high-grade retroperitoneal liposarcomas: personal experience

Sarcomas are uncommon malignant tumors arising from mesenchymal tissue, accounting for approximately 10% of soft-tissue sarcomas and less than 1% of all malignant neoplasms. The most frequent subtypes of retroperitoneal sarcomas are liposarcoma. Total surgical extirpation appears the only chance for patient cure since medical therapies have shown little efficacy. We have analyzed our series of 32 retroperitoneal liposarcoma that undergone surgical resection and with at least 5 years of follow-up. We have included 21 patients who underwent a complete resection (R0) and 6 patients who underwent an incomplete resection (R1). However, the operation's goal was a complete tumor resection with tumor-free resection margins. The 5-year survival was 85.7% when we performed a R0 resection, while it was 33.3% when we performed a R1 resection with a significant statistical difference (p = 0.02). Surgery is the gold standard for treatment of liposarcoma. Despite advances in diagnostic modalities, surgical techniques and the adoption of more aggressive procedure, such disease still has a propensity for local recurrence, even after an apparent complete resection. Therefore, locoregional recurrence remains the main cause of death in patients with a retroperitoneal liposarcoma. Moreover when the tumor recurs locally, the treatment of choice is to remove the recurrence. Our experience shows that a complete resection of primary lesions and further resection of recurrences early detected with CT examination could improve the overall survival of patients with retroperitoneal liposarcoma. Moreover in our series, the patients who undergo R1 resection had a worse prognosis.

Radiotherapy and surgery-an indispensable duo in the treatment of retroperitoneal sarcoma

The authors undertook a systematic review to designate the role that radiotherapy (RT) might play in the treatment of retroperitoneal sarcomas. Correlating with recent literature, the objective of this review was to evaluate whether there was enough evidence for the authors to develop an institutional treatment protocol concerning the use of RT in the treatment of retroperitoneal sarcoma. Furthermore, this was a call for surgeons to talk to radiation oncologists before performing surgery. The 2 objectives of this review were: 1) to determine the benefit of RT in terms of local control and/or survival in the treatment of retroperitoneal sarcomas and 2) to discover the optimal timing of RT in the treatment sequence. A computerized literature search was performed in the PubMed database, the Cochrane Library database, and reference lists; and journals also were searched by hand to identify all retrospective and prospective reports published since 1998 relating to RT treatment of adult retroperitoneal sarcoma. Mainly, analyses were sought that were based on a 5-year local control rate (LCR), 5-year disease-free survival, and 5-year overall survival (OS). If only 2 years follow-up were available, then the authors also noted this outcome. Toxicity data were collected and analyzed separately. The synthesis of the literature was based on 9 prospectively nonrandomized studies and 10 retrospective studies that, together, reviewed a total of 1426 patients. The 5-year LCR varied from 27% to 62%, and the results from other reports fell in between those values. The 5-year OS rate ranged from 12% to 90%, and complete resection and tumor grade were the most important prognostic factors in most studies. This review resulted in 7 recommendations concerning the use of RT in the treatment of retroperitoneal sarcoma. The authors concluded that there is good evidence from multiple single-institutions studies that RT improves the LCR in patients with retroperitoneal sarcoma. Until now, there has not been a translation of this approach into survival benefit. The current results indicated that preoperative external-beam RT followed by radical surgery seems to be the preferred sequence, and adding intraoperative RT is a safe procedure for dose escalation in the upper abdomen.

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.

Retroperitoneal leiomyosarcoma presenting as lower gastrointestinal bleeding: a case report and review of the literature

We report the first known case of a retroperitoneal leiomyosarcoma that presented with an endoscopically defined source of gastrointestinal bleeding in the colon. A 68-year-old male with a history of diverticulosis, hypertension, and hypercholesterolemia who complained of a 3-month history of abdominal pain, nausea, and intermittent hematochezia presented for evaluation of large volume hematochezia and lightheadedness. Colonoscopy revealed left-sided diverticulosis and rectal varices without stigmata of recent bleed. CT scan showed a 26 × 20 × 13 cm heterogeneous retroperitoneal mass and multiple hypodense hepatic lesions. Liver biopsy revealed leiomyosarcoma. In summary, although surgery is the mainstay of treatment, resectability has not improved significantly. Early recognition and aggressive surgery are keys to long-term survival.

Differentiated posterior cervical liposarcoma with carcinoid: report of a case

Liposarcoma most commonly arises in the retroperitoneum and lower extremities. Liposarcoma of the head and neck region is a rare and potentially life-threatening malignancy. Those originating in the right retrocervical space cause special diagnostic and therapeutic difficulties. In present report, a case of differentiated liposarcoma of the right cervical region with intestinal carcinoid is reported. The tumor continued to grow slowly over 3 years before a definitive diagnosis was established. Extended extirpation of the tumor and modified radical neck dissection, postoperative radiotherapy followed by chemotherapy were performed and proved to be efficacious in that no recurrence was observed for 2 years. Recommendations for earlier and correct diagnosis and treatment of this rare neoplasm are discussed.