Effect of radiation therapy on survival in surgically resected retroperitoneal sarcoma: a propensity score-adjusted SEER analysis

Orbital Liposarcoma: A Surveillance, Epidemiology and End Results Database Study

PURPOSE

Orbital liposarcoma is a challenging tumor to treat due to its rarity and high rate of local recurrence, and the role of radiotherapy and chemotherapy remain unclear. Analysis of big data may improve our overall understanding of orbital disease and role of adjuvant therapies.

METHODS

Data were extracted from the Surveillance, Epidemiology and End Results (SEER) Research Plus database from 1975 to 2017. All patients with a diagnosis of liposarcoma (ICD-O3 codes 8850-8858, 8869-8862, 8870, 8880, 8881) were included. Cases were divided into 4 groups by primary site: orbit, retroperitoneum, soft tissue, and other.

RESULTS

A total of 16,958 patients were included. Patients with orbital involvement were younger and more likely to be female ( p  < 0.05). Among orbital lesions, myxoid liposarcoma was the most common histologic subtype (6/19; 31.6%) followed by well differentiated (5/19; 26.3%). This differed from the distribution of histologic subtypes encountered elsewhere, for which well-differentiated liposarcoma was the most common (retroperitoneum 979/3,136; 31%, soft tissue 3,493/11,671; 30%, and other sites 497/2,132; 23%, p  < 0.05). Dedifferentiated histologic subtype was the second most common subtype found in the retroperitoneum (946/3,136; 30%), whereas it was less common in the orbit (2/19; 11%) and soft tissue (1,396/11,671; 12%) ( p  < 0.001). Patients with orbital liposarcoma had similar disease-specific mortality compared with soft-tissue location ( p  = 0.825) and lower disease-specific mortality compared with retroperitoneal location ( p  < 0.001). When all locations were combined, patients with well-differentiated liposarcoma had the lowest disease-specific mortality.

CONCLUSIONS

Patients with orbital liposarcoma tend to be younger, female, and have a better prognosis than those with retroperitoneal disease, likely due to the lower incidence of dedifferentiated histologic subtype.

The role of radiation therapy in the management of primary retroperitoneal sarcoma: A systematic review and clinical practice guidelines from the Australia and New Zealand Sarcoma Association

While surgery is the mainstay of treatment for localised retroperitoneal sarcoma, the use of radiotherapy (RT) remains controversial. This systematic review aimed to evaluate the role of RT for retroperitoneal sarcoma. A systematic review using the population, intervention, comparison, and outcome model from 1990 to 2022 identified 66 studies (a mixture of preoperative and postoperative RT); one randomised controlled trial (RCT) with two publications, 18 registry studies, and 46 retrospective studies. In the RCT of preoperative RT, there was no difference in local/abdominal recurrence. The pooled analysis of this RCT and a retrospective study showed a significant abdominal recurrence free survival benefit with preoperative RT in low grade liposarcoma. The RCT and the majority of retrospective series found RT did not improve recurrence free survival (11 of 16 no difference in combined local and distant RFS, 11 of 13 no difference in distant metastasis free survival), disease specific survival (9 of 12 studies) or overall survival (33 of 49 studies). The majority of studies found no association between RT and perioperative morbidity. In summary, preoperative RT may improve local control for low grade (well-differentiated or grades 1-2 dedifferentiated) liposarcoma, but not other histological subtypes. There is no strong evidence that perioperative RT provides an overall survival benefit. Patients with low grade retroperitoneal liposarcoma can be considered for preoperative RT to improve abdominal recurrence free survival. The rationale and level of evidence in this scenario should be carefully discussed by the multidisciplinary team with patients. RT should not be routinely recommended for other histological subtypes.

Web-based nomogram to predict postresection risk of distant metastasis in patients with leiomyosarcoma: retrospective analysis of the SEER database and a Chinese cohort

OBJECTIVES

This study investigated risk factors and constructed an online tool to predict distant metastasis (DM) risk in patients with leiomyosarcoma (LMS) after surgical resection.

METHODS

Data regarding patients with LMS who underwent surgical resection between 2010 and 2018 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Data were collected regarding patients with LMS who underwent surgical resection at Tianjin Medical University Cancer Hospital and Institute (TJMUCH) between October 2010 and July 2018. Patients were randomly divided into training and validation sets. Logistic regression analyses were performed; a nomogram was established. The area under the curve (AUC) and calibration curve were used to evaluate the nomogram, which served as the basis for a web-based nomogram.

RESULTS

This study included 4461 and 76 patients from the SEER database and TJMUCH, respectively. Age, ethnicity, grade, T stage, N stage, radiotherapy, and chemotherapy were associated with DM incidence. C-index values were 0.815 and 0.782 in the SEER and Chinese datasets, respectively; corresponding AUC values were 0.814 and 0.773, respectively. A web-based nomogram (https://weijunqiang-leimyosarcoma-seer.shinyapps.io/dynnomapp/) was established.

CONCLUSIONS

Our web-based nomogram is an accurate and user-friendly tool to predict DM risk in patients with LMS; it can aid clinical decision-making.

Risk and outcome of second primary malignancy in patients with classical Hodgkin lymphoma

BACKGROUND

Hodgkin lymphoma survivors demonstrated increased risk of secondary primary malignancies (SPMs), but comprehensive analysis of the risk and outcome of SPMs in classical Hodgkin lymphoma (cHL) patients has not yet been reported.

METHODS

Patients with cHL from 1975 to 2017 were identified from the Surveillance, Epidemiology and End Results (SEER) database. Standardized incidence ratios were calculated for the risk of solid and hematologic SPMs in cHL patients compared to the general population. The outcome of cHL patients developing SPMs were assessed by performing survival, competing risks regression, and cox proportional regression analyses.

RESULTS

In a follow-up of 26,493 cHL survivors for 365,156 person years, 3866 (14.59%) secondary cancers were identified, with an standardized incidence ratio of 2.09 (95% CI: 2.02-2.15). The increased risk was still notable after follow-up of 10 years or more, and the risk is more pronounced for patients with female gender, younger age, advanced stage, chemotherapy, and radiation therapy. The overall survival is worse for cHL patients with SPMs after 11 years of follow-up (P < .0001). The main cause of death for cHL patients with SPMs is not cHL but other causes including SPMs. Multivariate Cox regression analysis confirmed SPMs as an independently adverse prognostic factor for cHL survivors (hazard ratio, 1.13; 95% CI, 1.05-1.21, P = .001).

CONCLUSIONS

There is a significantly increased risk of developing SPMs for cHL survivors. The overall survival is worse for cHL patients and SPMs is an independent prognostic factor for cHL.

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

BACKGROUND

Little level 1 evidence exists to guide multimodality treatment in retroperitoneal soft tissue sarcoma (RPS), which may lead to significant variation in therapeutic approaches. This analysis aimed to describe national RPS treatment trends and explore potential variability among low-/high-volume hospitals (LVH/HVHs).

PATIENTS AND METHODS

In total, 5992 patients who underwent resection for primary RPS were retrospectively identified in the National Cancer Database (2004-2017). Time trend analyses examined rates of multivisceral resection (MVR), radiation, and chemotherapy use. LVHs were defined as those carrying out fewer than ten resections per year (N = 5433), whereas HVHs were defined as those carrying out ten or more (N = 559). Descriptive statistics and logistic regression models compared trends between groups.

RESULTS

MVR was more frequent at HVHs (63.7% versus 43.5%, p < 0.001). Use of radiation varied widely by hospital volume. HVHs more frequently employed preoperative radiation as compared with LVHs (14.7% versus 8.1%, p < 0.001). Throughout the study period, LVHs increased utilization of preoperative radiation (2.6% to 12.0%, p < 0.001) whereas rates at HVHs remained stable. Overall, LVHs utilized postoperative radiation significantly more frequently as compared with HVHs (14.7% versus 2.7%, respectively, p < 0.001). Postoperative radiation at LVHs remained stable until 2013 and sharply declined thereafter (16.7% to 6.9%, p < 0.001). Rates of postoperative radiation use at HVHs remained lower than those at LVHs at all time points.

CONCLUSIONS

Strategies for resection and radiation use at LVHs have trended towards those of HVHs. Current national implementation of preoperative radiation, MVR, and chemotherapy remains heterogeneous. These findings inform future trial design and support standardization of care.

Adjuvant therapy for retroperitoneal sarcoma: a meta-analysis

Background

Adjuvant therapy is a promising treatment to improve the prognosis of cancer patients, however, the evidence base driving recommendations for adjuvant radiotherapy (ART) or chemotherapy (ACT) in retroperitoneal sarcomas (RPS) primarily hinges on observational data. The aim of this study was to evaluate the effectiveness of adjuvant therapy in the management of RPS patients.

Methods

We searched PubMed, Web of Science, Embase, ASCO Abstracts, and Cochrane Library for comparative studies (until December 2020) of adjuvant therapy versus surgery alone. Data on the following endpoints were evaluated: overall survival (OS), local recurrence (LR), recurrence-free survival (RFS), and metastasis-free survival (MFS). Data were summarized as hazard ratios (HR) with 95% confidence intervals (CI). Risk of bias of studies was assessed with Begg’s and Egger’s tests.

Results

A total of 15 trials were eligible, including 9281 adjuvant therapy and 21,583 surgery alone cases (20 studies for OS, six studies for RFS, two studies for LR, and two studies for MFS). Meta-analysis showed that ART was associated with distinct advantages as compared to surgery alone, including a longer OS (HR = 0.80, P < 0.0001), a longer RFS (HR = 0.61, P = 0.0002), and a lower LR (HR = 0.31, P = 0.005). However, this meta-analysis failed to demonstrate a benefit of ACT for RPS patients, including OS (HR = 1.11, P = 0.19), RFS (HR = 1.30, P = 0.09) and MFS (HR = 0.69, P = 0.09). In the sensitivity analysis, ACT was associated with a worse OS (HR = 1.19, P = 0.0002). No evidence of publication bias was observed.

Conclusions

Overall, the quality of the evidence was moderate for most outcomes. The evidence supports that ART achieved a generally better outcome as compared to surgery alone.

Supplementary information

The online version contains supplementary material available at 10.1186/s13014-021-01774-w.

Role of Radiation Therapy for Newly Diagnosed Retroperitoneal Sarcoma

OPINION STATEMENT

Soft tissue sarcomas (STS) are rare, aggressive, and heterogenous tumors, comprising approximately 1% of adult cancers with over 50 different subtypes. The mainstay of treatment for retroperitoneal sarcomas (RPS) includes surgical resection. The addition of radiation therapy (RT), either preoperatively or postoperatively, has been used to potentially decrease the risk of local recurrence. The recently published results from STRASS (EORTC-STBSG 62092-22092), which randomized patients to receive or not receive preoperative radiation, indicate no abdominal recurrence-free survival benefit (primary endpoint) nor overall survival benefit to date from the addition of preoperative RT prior to surgical resection in patients with RPS. Keeping in mind caveats of subgroup analyses, the data show a significant reduction in local recurrence with radiation therapy in resected patients and non-significant trends toward improved abdominal recurrence-free survival in all patients and improved local control and abdominal recurrence-free survival in patients with liposarcoma and low-grade sarcoma. Given the high rate of local failure with surgery alone, it is possible that higher RT dose and/or selective RT dose painting may improve outcomes. Prior to treatment, the authors encourage multidisciplinary review and discussion of management options at a sarcoma center for patients with RPS. Selective use of RT may be considered for patients at high risk of local recurrence.

Giant retroperitoneal liposarcoma with a maximum diameter of 37 cm: a case report and review of literature

Retroperitoneal liposarcoma is a rare malignancy derived from adipocytes. They can grow to large sizes before inducing clinical symptoms. Giant retroperitoneal liposarcoma with a diameter over 30 centimeters is extremely rare. So far, only 13 cases of giant retroperitoneal liposarcoma with a diameter greater than 30 cm have been reported. There is very little experience in the treatment of these bulky tumors. Herein, we report a 65-year-old male patient diagnosed with giant retroperitoneal liposarcoma. The patient underwent successful complete surgical resection. The tumor was found to occupy almost the entire abdominal cavity, measuring 37.0 cm × 32.0 cm × 26.5 cm in size and 21.0 kg in weight. Histopathological analysis indicated a grade I, well-differentiated liposarcoma. The patient was discharged uneventfully, and no sign of recurrence was observed at 12-month follow-up. Moreover, we reviewed 13 literatures in English published on PubMed database regarding retroperitoneal liposarcoma greater than 30 cm in diameter. The analysis suggests that size alone should not be considered as a contraindication to surgical resection. Combined resection of adjacent organs is necessary if local invasion is confirmed. The role of adjuvant radio or chemotherapy remains controversial. Thorough evaluation on the extent of resection should be made to minimize post-surgery decline in quality of life.

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.

Neoadjuvant radiotherapy followed by surgery compared with surgery alone in the treatment of retroperitoneal sarcoma: a population-based comparison

Introduction

Retroperitoneal sarcoma (rps) encompasses a heterogeneous group of malignancies with a high recurrence rate after resection. Neoadjuvant radiotherapy (nrt) is often used in the hope of sterilizing margins and decreasing local recurrence after excision. We set out to compare local recurrence-free survival (lrfs) and overall survival (os) in patients treated with or without nrt before resection.

Methods

Patients diagnosed with rps from February 1990 to October 2014 were identified in the Alberta Cancer Registry. Patients with complete gross resection of rps and no distant disease were included. Patient, tumour, treatment, and outcomes data were abstracted in a primary chart review. Baseline characteristics were compared using the Wilcoxon nonparametric test for continuous data and the Fisher exact test for dichotomous and categorical data. Survival was analyzed using Kaplan-Meier curves with log-rank test. Cox regression was performed to control for age, sex, tumour size, tumour grade, date of diagnosis, multivisceral resection, and intraoperative rupture.

Results

Resection alone was performed in 62 patients, and resection after nrt, in 40. Use of nrt was associated with multivisceral resection and negative microscopic margins. On univariate analysis, nrt was associated with superior median lrfs (89.3 months vs. 28.4 months, p = 0.04) and os (119.4 months vs. 75.9 months, p = 0.04). On multivariate analysis, nrt, younger age, and lower tumour grade predicted improved lrfs and os; sex, tumour size, date of diagnosis, multivisceral resection, and tumour rupture did not.

Conclusions

In this population-based study, nrt was associated with superior lrfs and os on both univariate and multivariate analysis. When feasible, nrt should be considered until a randomized controlled trial is completed.

Retroperitoneal soft tissue sarcoma: low-dose neoadjuvant radiation therapy followed by surgery with or without intraoperative radiotherapy and adjuvant radiation therapy

BACKGROUND

We describe the clinical history, outcome, and toxicity of five patients with high-grade retroperitoneal soft tissue sarcoma (RSTS) who were treated with neoadjuvant low-dose radiotherapy (RT) followed by resection with or without intraoperative radiotherapy (IORT), followed by adjuvant RT. We aim to provide additional evidence for the various treatment options that exist for this rare tumor entity.

METHODS

Most patients presented with mild abdominal symptoms. Diagnosis was confirmed by biopsy. Additional imaging was done by sonography, magnetic resonance imaging (MRI), and/or positron emission tomography (PET)/computed tomography (CT). All patients were treated with neoadjuvant RT of 19.8 Gy in 1.8-Gy fractions followed by resection and postoperative RT up to 45 Gy with a median interval between resection and start of postoperative RT of 5 weeks. Two patients received additional IORT. Median follow-up was 61 months.

RESULTS

One patient developed a local recurrence that was diagnosed 30 months after the start of the first therapy. He was treated with a salvage resection and had no evidence of disease at the last follow-up. Another patient developed a right-sided RSTS on the contralateral side from the primary radiation field with pelvic bone infiltration 56 months after the start of RT. He was treated again by RT and resection and was without evidence of disease at last follow-up. Radiotherapy was well tolerated without major toxicity.

CONCLUSION

The treatment of RSTS by low-dose neoadjuvant RT, resection with IORT and adjuvant RT seems to be a feasible and effective treatment approach. Further studies comparing neoadjuvant with adjuvant RT are necessary to find the best treatment option.

Radiation Therapy for Retroperitoneal Sarcomas: Influences of Histology, Grade, and Size

Perioperative radiation therapy (RT) has been associated with reduced local recurrence in patients with retroperitoneal sarcomas (RPS); however, selection criteria remain unclear. We hypothesized that perioperative RT would improve survival in patients with RPS and would be associated with pathological factors. The National Cancer Database (NCDB) from 2004 to 2012 was reviewed for patients with nonmetastatic RPS undergoing curative intent resection. Tumor size was dichotomized at 15 cm based on 8th edition American Joint Committee on Cancer (AJCC) staging. Patients with the highest comorbidity score were excluded. Unadjusted Kaplan–Meier and adjusted Cox proportional hazards modeling analyzed overall survival (OS). Multivariable logistic regression modeled margin positivity. A total of 2,264 patients were included; 727 patients (32.1%) had perioperative radiation in whom 203 (9.0%) had radiation preoperatively. Median (IQR) RPS size was 17.5 [11.0–27.0] cm. Histopathology was high grade in 1048 patients (43.7%). Multivariable analysis revealed that perioperative radiation was independently associated with decreased mortality (HR 0.72, 95% confidence intervals (CIs) 0.62–0.84, p < 0.001), and preoperative RT was associated with reduced margin positivity (HR 0.72, 95% CI 0.53–0.97, p=0.032). Stratified survival analysis showed that radiation was associated with prolonged median OS for RPS that were high-grade (64.3 vs. 43.6 months, p < 0.001), less than 15 cm (104.1 vs. 84.2 months, p=0.007), and leiomyosarcomatous (104.8 vs. 61.8 months, p < 0.001). Perioperative radiation is independently associated with decreased mortality in patients with high-grade, less than 15 cm, and leiomyosarcomatous tumors. Preoperative radiation is independently associated with margin-negative resection. These data support the selective use of perioperative radiation in the multidisciplinary management of RPS.

Efficacy of Postoperative Radiotherapy Using Modern Techniques in Patients with Retroperitoneal Soft Tissue Sarcoma

PURPOSE

Local recurrence is the most common cause of failure in retroperitoneal soft tissue sarcoma patients after surgical resection. Postoperative radiotherapy (PORT) is infrequently used due to its high complication risk. We investigated the efficacy of PORT using modern techniques in patients with retroperitoneal soft tissue sarcoma.

MATERIALS AND METHODS

Eighty patients, who underwent surgical resection for non-metastatic primary retroperitoneal soft tissue sarcoma at the Yonsei Cancer Center between 1994 and 2015, were retrospectively reviewed. Thirty-eight (47.5%) patients received PORT: three-dimensional conformal radiotherapy in 29 and intensity-modulated radiotherapy in nine patients. Local failure-free survival (LFFS), overall survival (OS), and RT-related toxicities were investigated.

RESULTS

Median follow-up was 37.1 months (range, 5.8-207.9). Treatment failure occurred in 47 (58.8%) patients including local recurrence in 33 (41.3%), distant metastasis in eight (10%), and both occurred in six (7.5%) patients. The 2-year and 5-year LFFS rates were 63.9% and 47.9%, respectively. The 2-year and 5-year OS rates were 87.5% and 71.1%. The 5-year LFFS rate was significantly higher in PORT group than in no-PORT group (74.2% vs. 24.3%, p<0.001). In multivariate analysis, PORT was the only independent prognostic factor for LFFS. However, there was no significant correlation between RT dose and LFFS. OS showed no significant difference between the two groups. Grade ≤2 acute toxicities were observed in 63% of patients, but no acute toxicity ≥grade 3 was observed.

CONCLUSION

PORT using modern technique markedly reduced local recurrence in retroperitoneal sarcoma patients, with low toxicity. The optimal RT technique, in terms of RT dose and target volume, should be further investigated.

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.

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.

Contemporary reappraisal of the efficacy of adjuvant chemotherapy in resected retroperitoneal sarcoma: Evidence from a nationwide clinical oncology database and review of the literature

BACKGROUND

While margin-negative resection remains the cornerstone of therapy for retroperitoneal sarcoma (RPS), the impact of adjuvant chemotherapy (AC) on overall survival (OS) remains poorly understood.

METHODS

The National Cancer Data Base was queried for patients undergoing curative-intent resection of primary non-metastatic RPS (2004-2013). Multivariable modeling identified factors associated with AC receipt. Cox regression identified covariates associated with OS, and AC and surgery alone (SA) cohorts were matched 1:1 by propensity scores based on these covariates. In the propensity-score matched cohort, OS was compared by Kaplan-Meier estimates. Results from this analysis were presented in the context of a review of the existing literature on the impact of AC in resected RPS.

RESULTS

Of 3892 resected RPS patients, 90.0% and 10.0% received SA and AC, respectively. Predictors of AC receipt included younger age, non-Caucasian race, hospital location, histologic grade, adjacent organ invasion, and histologic subtype. The propensity score-matched cohort comprised 767 patients (SA n = 377; AC n = 390); at a median follow-up of 59.2 (IQR 35.0-85.3) months, median OS of the propensity-matched cohort was 53.6 (IQR 22.4-119.5) months. Utilization of AC was associated with significantly worse long-term survival (median OS: 47.8 vs. 68.9 months, p = 0.017; HR 1.30, 95% CI 1.05-1.61). AC was not associated with improved OS in margin-positive (R1/R2) resection, high-grade (G2/G3) and larger (>10 cm) tumors, or in any histologic subtype. Albeit not statistically significant, there was a trend toward improved OS with AC in spindle cell (HR 0.37, 95% CI 0.10-1.38), giant cell (HR 0.82, 95% CI 0.32-2.13), and synovial (HR 0.26, 95% CI 0.05-1.33) sarcoma.

CONCLUSIONS

Data from a large nationwide oncology database and review of the existing literature do not support adjuvant chemotherapy regimens following curative-intent resection of RPS, even in subgroups at high risk of failure (e.g., R1/R2 resection, high-grade or large tumors). The possible benefit of conventional adjuvant regimens in spindle cell, giant cell, and synovial sarcoma should be explored in prospective studies.

Retroperitoneal Sarcomas

Retroperitoneal sarcomas are rare tumors, representing only 15% of all sarcomas. The mainstay of therapy is surgical resection with negative margins. However, this is challenging because of the late presentation of many of these tumors and involvement with adjacent structures. Decisions on radiation therapy and chemotherapy should be made in a multidisciplinary setting at a tertiary referral center.

Proton beams in cancer treatments: Clinical outcomes and dosimetric comparisons with photon therapy

PURPOSE

To review current evidence of the role of proton therapy (PT) in other tumors than skull base, sinusal/parasinusal, spinal and pediatric tumors; to determine medico-economic aspects raised by PT.

MATERIAL AND METHODS

A systematic review on Medline was performed with the following keywords: proton therapy, proton beam, protontherapy, cancer; publications with comparison between PT and photon-therapy were also selected.

RESULTS

In silico studies have shown superiority (better dose delivery to the target and/or to organs at risk) of PT toward photon-therapy in most of thoracic and abdominal malignant tumors. Potential benefits of PT could be: reduction of toxicities (including radiation-induced cancer), increase of tumor control through a dose-escalation approach, hypofractionation. Cost of treatment is always cited as an issue which actually can be managed by a precise patient selection making PT a cost-effective procedure. Comparison plan with photon therapy may be useful to determine the dosimetric and clinical advantages of PT (Normal Tissue Complications Probability).

CONCLUSION

PT may be associated with a great advantage compared to the best photon-therapies in various types of cancers. Accumulation of clinical data is on-going and will challenge the in silico data analysis. Some indications are associated with strong superiority of PT and may be discussed as a new standard within prospective observational studies.

Retroperitoneal liposarcoma: a comprehensive review

Retroperitoneal liposarcomas are rare mesenchymal tumors of the retroperitoneum that typically present with advanced disease and often carry a poor prognosis. Because of their rarity and anatomic location, these malignant tumors can cause a diagnostic dilemma and present several therapeutic challenges. They are usually associated with a high rate of recurrence despite grossly complete resection, thus requiring long-term and often indefinite follow-up. Relevant data on this topic was procured and synthesized with the aid of a comprehensive Medline search in addition to oncologic, pathologic, urologic, radiologic, and surgical literature review on retroperitoneal sarcomas. This article provides an in-depth review into the natural history, pathology, clinical manifestations, and prognostic features of retroperitoneal liposarcomas. It also discusses the reliability of diagnostic procedures and novel curative approaches that are currently being evaluated for the disease.

[Current situation and perspectives of proton therapy]

Proton beam therapy is indicated as a treatment for some rare tumours and paediatric tumours because the technique allows a good local control with minimal toxicity; the growing number of centres that use proton beam therapy is associated with an increase of dosimetric and clinical data for other malignant tumours as well. This paper reviews potential indications of proton beam therapy. A systematic review on Medline was performed with the following keywords proton beam therapy, cancer, heavy particle, charged particle. No phase III trial has been published using proton beam therapy in comparison with the best photon therapy, but numerous retrospective and dosimetric studies have revealed an advantage of proton beam therapy compared to photons, above all in tumours next to parallel organs at risk (thoracic and abdominal tumours). This could be accompanied with a better safety profile and/or a better tumoural control; numerous phase 0, I, II, III and IV studies are ongoing to examine these hypotheses in more common cancers. Use of proton beam therapy is growing for common cancers within clinical trials but some indications could be applied sooner since in silico analysis showed major advantages with this technique.

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.

[Multimodal management in soft tissue sarcoma of the trunk and extremities]

Soft tissue sarcoma (STS) is a rare, extremely heterogeneous group of malignant tumors of mesodermal origin. With an incidence of 1-5 per 100,000/year they account for only 1 % of all human malignancies. The STSs occur predominantly in the lower extremities and the trunk. To date 100 different histopathological subentities can be defined. The prognosis varies substantially depending on the localization and histology. Whereas local recurrence rates and overall survival of sarcomas of the extremities have benefited from the introduction of multimodal therapies, only marginal progress has been made in the management of trunk STSs. This manuscript gives an overview of preoperative diagnostics, pathology and neoadjuvant as well as adjuvant therapeutic options for soft tissue sarcoma.

The role of radiation in retroperitoneal sarcomas

OPINION STATEMENT

Retroperitoneal sarcomas form a group of rare malignancies that require expertise in every aspect of management. Patients benefit from referral to cancer centers that can provide comprehensive, multidisciplinary, oncologic management. The role of radiation in retroperitoneal sarcoma management is, appropriately, the subject of considerable controversy due to the absence of high-level evidence proving its efficacy. Nonetheless, the preponderance of available data suggests that radiation therapy likely improves local control and, in some settings, may favorably impact resectability and survival. These outcome observations coupled with the lower doses (45-54 Gy) and normal tissue displacement characteristic of preoperative radiation therapy leads us to favor preoperative radiotherapy followed by oncologic resection for most retroperitoneal sarcomas. This strategy appears to provide the highest chance of safe and successful delivery of multimodal therapy, which can otherwise be hindered by postoperative complications as a result of technically challenging surgery and normal tissue radiation dose tolerances. Dose-escalation and selective integrative boosts to "at-risk" margins are attractive strategies that merit, and arguably require, further clinical evaluation. We believe that postoperative radiotherapy should be reserved for very high-risk cases and should be treated to a dose of ≥60 Gy respecting normal tissue dose tolerances. An additional approach that we consider in the postoperative setting is close surveillance with consideration of preoperative radiotherapy at recurrence before repeat surgical resection. Highly conformal radiotherapy techniques, such as IMRT with image guidance, should be employed to minimize dose to normal tissues and thereby allow delivery of efficacious radiation doses. If feasible, referral to a treatment facility with proton beam therapy should be discussed with the patient, especially if normal tissue dose constraints cannot be met using IMRT/IGRT. Participation in prospective studies should be highly encouraged.

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.

Should adjuvant radiotherapy be administered in addition to front-line aggressive surgery (FAS) in patients with primary retroperitoneal sarcoma?

BACKGROUND

As most patients with retroperitoneal sarcomas (RPS) die of local recurrence, front-line aggressive surgery (FAS) has been developed, and it seems to achieve better local control. The aim of this study was to evaluate conformal postoperative radiotherapy (PORT) in patients who had enlarged surgery.

PATIENTS AND METHODS

Between 1994 and 2008, 110 patients with primary RPS mainly operated by FAS were analysed. Sixty-two patients underwent surgery and no PORT (group S), and 48 received surgery and PORT (group S + R). The median age was 52. Most patients had 3D conformal PORT (81%) with a median dose of 50 Gy.

RESULTS

Comparing results at 5 years in the S and the S + R group, the cumulative rate of local failure was, respectively, 36% and 22% (NS); relapse-free survival was 47% and 60% (P = 0.02), and overall survival was, respectively, 77% and 71% (NS).

CONCLUSION

Even if patients with adjuvant PORT were at higher risk of recurrence, there was a trend for radiotherapy (RT) to decrease the local relapse rate and improve recurrence-free survival. This study confirms that adjuvant conformal RT should be evaluated in a randomized trial, the control arm being FAS. Adjuvant RT in the preoperative setting is being evaluated in an EORTC trial.