Long-term results of two prospective trials of preoperative external beam radiotherapy for localized intermediate- or high-grade retroperitoneal soft tissue sarcoma

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.

Local Control of Soft Tissue and Bone Sarcomas

Sarcomas of soft tissue and bone are mesenchymal malignancies that can arise in any anatomic location, most commonly the extremity, retroperitoneum, and trunk. Even for lower grade histologic subtypes, local recurrence can cause significant morbidity and even disease-related death. Although surgery remains the cornerstone of local control, perioperative radiation and systemic therapy are often important adjuvants. This review will summarize the current therapeutic approaches for local control of soft tissue and bone sarcomas.

Surgical morbidity in retroperitoneal sarcoma resection

Resection of retroperitoneal sarcoma (RPS) typically involves multivisceral resection. The morbidity of RPS resection has decreased over time despite widespread adoption of radical resection. Certain patterns of resection are associated with higher complication rates and elderly patients are at increased risk of morbidity. Administration of preoperative radiotherapy does not increase morbidity, but intraoperative and brachytherapy techniques are associated with heightened toxicities. Long-term functional outcomes and quality of life scores after RPS resection are acceptable.

Long-Term Quality of Life of Retroperitoneal Sarcoma Patients Treated with Pre-Operative Radiotherapy and Surgery

Purpose: Retroperitoneal sarcomas (RPS) are connective tissue cancers that are often large and anatomically in close proximity to critical and radiation-sensitive normal structures and organs within the abdomen and pelvis. The management of RPS may include preoperative radiotherapy (RT) and surgery. We aimed to examine how treatment-related toxicities affect patient quality of life (QOL). 

Methods and materials: Within two prospective cohort studies, 48 RPS patients who were treated with preoperative RT from 1998-2012 were recruited and assessed for QOL (EORTC-QLQ-C30) and to determine toxicities potentially related to RT and surgery (graded using CTCAE V.4). Baseline and prospective QOL was available for 11 patients. In the other 37 patients, prospective data were obtained at different time points during their follow-up. Unless stated otherwise, all scores refer to the global QOL subscale.

Results: The patients' median age was 57 (38-82) and RT was administered to a median dose of 45 Gy (41.4-50.4). The median maximum tumor dimension was 16.0 cm (5.7-28) and the majority (35/48) were liposarcomas. The mean pre-RT QOL was 48.5/100. At one month post-RT, the mean QOL improved to 54.2; however, the mean diarrhea symptom scale worsened from baseline (78.3 vs. 18.2, p<0.001). Correspondingly, 54% of patients had gastrointestinal toxicities (92% G1-2 and 8% G3) by the end of RT. At 36 months post-RT, 88% of patients had chronic toxicities (19% G3). RPS patients who survived and are free of recurrence ≥ 36 months had significantly (mean: 75.0; p=0.001) better QOL than at diagnosis. The number of toxicities was significantly (p=0.001) associated with QOL. RT dose, tumor size, patient age, and patient gender were not associated with 36-month QOL. 

Conclusions: Treatment toxicities seem to contribute to QOL recovery during the first 36 months. QOL at 36 months was better than at diagnosis.

Randomized Controlled Trials in Soft Tissue Sarcoma: We Are Getting There!

Soft tissue sarcoma (STS) is a family of malignancies for which individual management decisions can be complex. There is a paucity of level 1 evidence, as the rarity and heterogeneity of STS pose challenges to the design and execution of randomized controlled trials. Radiotherapy (RT) is routinely used to facilitate function-preserving surgery and to improve local control. Delivery of RT in the preoperative setting can decrease chronic toxicities at the cost of increased wound complications in the short-term. The role of adjuvant systemic therapies remains controversial in adult STS.

Importance of preoperative diagnosis for management of patients with suspected retroperitoneal sarcoma

Soft tissue sarcoma is an umbrella term which encompasses over 60 histological tumour types. Approximately 15% of soft tissue sarcomas arise in the retroperitoneum. This complex group of tumours poses unique management challenges due to their often large size, histological heterogeneity and complexity of anatomical relationships. This review discusses the management of retroperitoneal tumours including the need for preoperative diagnosis, the evidence for neoadjuvant radiotherapy, the role of multivisceral resection and the importance of a multidisciplinary team approach.

Single-center experience with intra-abdominal liposarcoma: Optimal minimum duration for postoperative remnant tumor screening

This study sought to identify factors related to the prognosis of intra-abdominal liposarcoma and to determine the optimal minimum duration for remnant tumor screening. Intra-abdominal liposarcoma is associated with high rates of incomplete resection and recurrence requiring a sophisticated follow-up strategy.Patients who underwent surgery for intra-abdominal liposarcoma were included. Cox analyses were used to analyze factors related to recurrence and survival. To determine the optimal minimum duration for remnant tumor screening, patients with recurrence after surgery despite gross complete resection were grouped by a postoperative detection time of 1, 3, or 6 months. Their survivals were compared to the gross incomplete resection group.A total of 168 patients were included. Kaplan-Meier 5-year disease-free survival was 35.9% and overall survival was 66.5%. Multiplicity (HR=2.528, CI=1.585-4.033, P < .001), organ invasion (HR = 1.628, CI = 1.020-2.598, P = .041), and FNCLCC grades (G2,HR = 1.730, CI = 1.000-2.994; G3, HR = 3.812, CI = 2.112-6.880, P < .001) were related to recurrence. Multiplicity (HR = 2.131, CI = 1.050-4.329, P = .036), organ resection ≥3 (HR = 2.857, CI = 1.322-6.174, P = .008), gross incomplete resection (HR = 4.368, CI = 1.890-10.097, P = .001), positive margin (HR = 2.766, CI = 1.367-5.600, P = .005), FNCLCC grade (G2,HR = 2.044, CI = 0.937-4.459; G3,HR = 4.470, CI = 1.893-10.557; P = .003), and RT (HR = 0.322, CI = 0.160-0.648, P = .001) were related to overall survival. Dividing patients into 1 month (P = .097) and 3 months (P = 0.063) did not yield significant differences in univariate analyses, whereas 6 months showed significant difference (P = .015) compared to the gross incomplete resection group. Patients with tumors detected within 6 months showed similar survival to the gross incomplete resection group (HR = 0.552, CI = 0.241-1.260, P = .158), whereas patients with tumor detection after 6 months showed better survival (HR = 0.325, CI = 0.149-0.708, P = .005).In conclusion, minimum duration of 6 months for remnant tumor screening using CT seems optimal.

Intraoperative radiotherapy: review of techniques and results

Intraoperative radiotherapy (IORT) is a technique that involves precise delivery of a large dose of ionising radiation to the tumour or tumour bed during surgery. Direct visualisation of the tumour bed and ability to space out the normal tissues from the tumour bed allows maximisation of the dose to the tumour while minimising the dose to normal tissues. This results in an improved therapeutic ratio with IORT. Although it was introduced in the 1960s, it has seen a resurgence of popularity with the introduction of self-shielding mobile linear accelerators and low-kV IORT devices, which by eliminating the logistical issues of transport of the patient during surgery for radiotherapy or building a shielded operating room, has enabled its wider use in the community.

Electrons, low-kV X-rays and HDR brachytherapy are all different methods of IORT in current clinical use. Each method has its own unique set of advantages and disadvantages, its own set of indications where one may be better suited than the other, and each requires a specific kind of expertise.

IORT has demonstrated its efficacy in a wide variety of intra-abdominal tumours, recurrent colorectal cancers, recurrent gynaecological cancers, and soft-tissue tumours. Recently, it has emerged as an attractive treatment option for selected, early-stage breast cancer, owing to the ability to complete the entire course of radiotherapy during surgery. IORT has been used in a multitude of roles across these sites, for dose escalation (retroperitoneal sarcoma), EBRT dose de-escalation (paediatric tumours), as sole radiation modality (early breast cancers) and as a re-irradiation modality (recurrent rectal and gynaecological cancers).

This article aims to provide a review of the rationale, techniques, and outcomes for IORT across different sites relevant to current clinical practice.

Postoperative complications following intraoperative radiotherapy in abdominopelvic malignancy: A single institution analysis of 113 consecutive patients

BACKGROUND

Intraoperative radiotherapy (IORT) has advantages over external beam radiation therapy (EBRT). Few studies have described side effects associated with its addition. We evaluated our institution's experience with abdominopelvic IORT to assess safety by postoperative complication rates.

METHODS

Prospectively collected IRB-approved database of all patients receiving abdominopelvic IORT (via high dose rate brachytherapy) at Johns Hopkins Hospital between November 2006 and May 2014 was reviewed. Patients were discussed in multidisciplinary conferences. Those selected for IORT were patients for whom curative intent resection was planned for which IORT could improve margin-negative resection and optimize locoregional control. Perioperative complications were classified via Clavien-Dindo scale for postoperative surgical complications.

RESULTS

A total of 113 patients were evaluated. Most common diagnosis was sarcoma (50/113, 44%) followed by colorectal cancer (45/113, 40%), most of which were recurrent (84%). There were no perioperative deaths. A total of 57% of patients experienced a complication Grade II or higher: 24% (27/113) Grade II; 27% (30/113) Grade III; 7% (8/113) Grade IV. Wound complications were most common (38%), then gastrointestinal (25%). No radiotherapy variables were significantly associated with complications on uni/multi-variate analysis.

CONCLUSIONS

Our institution's experience with IORT demonstrated historically expected postoperative complication rates. IORT is safe, with acceptable perioperative morbidity.

The Role for Radiation Therapy in the Management of Sarcoma

Although there is no consensus regarding the optimal sequencing of external beam radiotherapy and surgery for extremity soft tissue sarcoma, radiation therapy delivered before or after limb-sparing surgery significantly improves local control, particularly for high-grade tumors. Large database analyses suggest that improved local control may translate into an overall survival benefit. Best practices require ample communication between the radiation and surgical teams to ensure appropriate tissues are targeted, unnecessary radiation is avoided, and patients are afforded the best opportunity for cure while maintaining function. Modern experiences with intensity-modulated radiotherapy/image-guided radiation therapy suggest toxicity is reduced through field size reduction and precise targeting, improving the therapeutic ratio.

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.

Intraoperative radiation therapy (IORT) in soft-tissue sarcoma

Soft-tissue sarcoma (STS) represent a rare tumor entity, accounting for less than 1% of adult malignancies. The cornerstone of curative intent treatment is surgery with free margins, although the extent of the surgical approach has been subject to change in the last decades. Multimodal approaches usually including radiation therapy have replaced extensive surgical procedures in order to preserve functionality while maintaining adequate local control. However, the possibility to apply adequate radiation doses by external beam radiation therapy (EBRT) can be limited in some situation especially in case of directly adjacent organs at risk with low radiation tolerance. Application of at least a part of the total dose via intraoperative radiation therapy (IORT) with a single fraction during the surgical procedure may overcome those limitations, because radiosensitive structures can be moved out of the radiation field resulting in reduced toxicity while the enhanced biological effectivity of the high single dose improves local control. The current review summarizes rationale, techniques, oncological and functional outcomes including possible pitfalls and associated toxicities based on the published literature for IORT focusing on extremity and retroperitoneal STS. In extremity STS, combination of limb-sparing surgery, IORT and pre- or postoperative EBRT with moderate doses consistently achieved excellent local control rates at least comparable to approaches using EBRT alone but usually including patient cohorts with higher proportions of unfavourable prognostic factors. Further on, IORT containing approaches resulted in very high limb preservation rates and good functional outcome, probably related to the smaller high dose volume. In retroperitoneal STS, the combination of preoperative EBRT, surgery and IORT consistently achieved high local control rates which seem superior to surgery alone or surgery with EBRT at least with regard to local control and in some reports even to overall survival. Further on, preoperative EBRT in combination with IORT seems to be superior to the opposite combination with regard to local control and toxicity. No major differences in wound healing disturbances or postoperative complication rates can be observed with IORT compared to non-IORT containing approaches. Neuropathy of major nerves remains a dose limiting toxicity requiring dose restrictions or exclusion from target volume. Gastrointestinal structures and ureters should be excluded from the IORT area whenever possible and the IORT volume should be restricted to the available minimum. Nevertheless, IORT represents an ideal boosting method if combined with EBRT and properly executed by experiences users which should be further evaluated preferably in prospective randomized trials.

Effect of intraoperative radiotherapy in the treatment of retroperitoneal sarcoma

BACKGROUND

Current National Comprehensive Cancer Network guidelines for the treatment of retroperitoneal sarcomas (RPS) endorse surgical resection, but the role of radiotherapy (RT) is less clear. We investigate the utilization and benefits of intraoperative RT (IORT) in the treatment of RPS.

METHODS

We queried the Surveillance, Epidemiology and End Results (SEER) database (1988-2013) for the utilization of IORT and perioperative external beam RT (EBRT) in patients who underwent surgical resection of RPS. Groups were defined as any IORT (aIORT), IORT alone (IORT-), IORT with EBRT (IORT+) and preoperative and/or postoperative EBRT without IORT (EBRT). Demographics, tumor characteristics, extent of disease, and survival were compared between groups.

RESULTS

We identified 908 patients with RPS who underwent surgical resection with perioperative RT. Demographics of age, sex, and race were similar between groups. There was no difference in baseline tumor characteristics of mean size, tumor grade, or histological subtype between groups. A higher percentage of patients receiving aIORT had tumors >20 cm in size, and extension beyond local tissues. Liposarcoma and leiomyosarcoma were the most common subtypes overall and in each subgroup. Patients with liposarcoma undergoing IORT and EBRT (IORT+) demonstrated a survival benefit over both IORT alone (IORT-) and EBRT alone.

CONCLUSION

IORT was used infrequently for RPS but generated equivalent outcomes compared to EBRT, despite being utilized more often for larger tumors and those with peri-tumoral soft-tissue invasion. Patients with the most common subtype (liposarcoma) may benefit from combination IORT with adjuvant EBRT versus other regimens.

Recent advances in the management of liposarcoma

Liposarcoma is the most common soft tissue sarcoma. With its various subtypes, the natural history of this disease can vary significantly from a locally recurrent tumor to a highly malignant one carrying a poor prognosis. Progress in the understanding of the specific molecular abnormalities in liposarcoma provides greater opportunity for new treatment modalities. Although surgical resection and radiation therapy remain the keystones for the management of primary liposarcoma, the inclusion of novel agents that target known abnormalities in advanced liposarcoma enhances the potential for improved outcomes.

Primary retroperitoneal soft tissue sarcoma: Imaging appearances, pitfalls and diagnostic algorithm

Although retroperitoneal sarcomas are rare tumours, they can be encountered by a wide variety of clinicians as they can be incidental findings on imaging or present with non specific symptoms and signs. Surgical resection can offer hope of cure and patient outcomes are improved when patients are managed in high-volume specialist centers. Failure to recognize retroperitoneal sarcomas on imaging can lead to inappropriate management in inexperienced centers. Therefore it is critical that a diagnosis of retroperitoneal sarcoma should be considered in the differential diagnosis of a retroperitoneal mass with prompt referral to a soft tissue sarcoma unit. In particular, the most common retroperitoneal sarcoma subtypes, liposarcoma and leiomyosarcoma, have characteristic imaging appearances which are discussed. This review therefore aims to set the context and guide clinicians through a diagnostic pathway for retroperitoneal masses in adults which arise extrinsic to the solid abdominal viscera.

Preoperative radiotherapy in the management of retroperitoneal liposarcoma

BACKGROUND

Histological subtype influences both prognosis and patterns of treatment failure in retroperitoneal sarcoma. Previous studies on the efficacy of neoadjuvant radiotherapy (NRT) have incorporated multiple histological types with heterogeneous tumour biology. The survival impact of NRT specifically for patients with retroperitoneal liposarcoma is poorly defined.

METHODS

Patients who underwent resection with curative intent for retroperitoneal liposarcoma and who received NRT or surgery alone were identified in the US National Cancer Data Base (2004-2013). Cox regression was used to identify co-variables associated with overall survival. NRT and surgery-alone cohorts were matched 1 : 1 by propensity scores based on the survival hazard on Cox modelling. Overall survival was compared by Kaplan-Meier estimates.

RESULTS

A total of 2082 patients with retroperitoneal liposarcoma were identified; 1908 underwent surgery alone and 174 received NRT before surgical resection. Median tumour size was 22·0 cm and 34·9 per cent of tumours were high grade. In the unmatched cohort, NRT was not associated with improved overall survival (χ²  = 3·49, P = 0·062). In the propensity score-matched cohort, NRT was associated with an improvement in survival (median overall survival 129·2 versus 84·3 months; P = 0·046; hazard ratio (HR) 1·54, 95 per cent c.i. 1·01 to 2·36). This effect appeared most pronounced for tumours with adjacent organ invasion (median overall survival not reached versus 63·8 months; P = 0·044; HR 1·79, 1·01 to 3·19).

CONCLUSION

NRT improved survival in patients undergoing surgery for retroperitoneal liposarcoma, particularly those with high-risk pathological features.

Preoperative radiation therapy combined with radical surgical resection is associated with a lower rate of local recurrence when treating unifocal, primary retroperitoneal liposarcoma

BACKGROUND AND OBJECTIVES

Local recurrence (LR) is the primary cause of death in patients with retroperitoneal liposarcoma (RP-LPS). The purpose of this study was to evaluate if the addition of preoperative radiation therapy (XRT) to radical resection for RP-LPS at a single institution was associated with improved LR.

METHODS

This retrospective analysis included patients with unifocal, primary RP-LPS who underwent complete R0/R1 resection at a single institution between 1991 and 2013. Multiple patient, tumor, and surgeon characteristics were tested to evaluate their association to LR (recurrence in the retroperitoneal space). We used competing risk hazards regression to evaluate the effect of preoperative XRT on the probability of LR.

RESULTS

There were 41 patients with liposarcoma histology whose tumors included entirely well-differentiated (N = 13), de-differentiated components (n = 26), myxoid (n = 1), and NOS (n = 1). Preoperative XRT was significantly associated with a lower probability of LR (HR 0.11, 95%CI 0.01-0.91, P = 0.04) and a higher 5-year local recurrence-free survival (95.6%, 95%CI 72.4-99.4%, vs. 75.0%, 95%CI 40.8-91.2%; P = 0.0213), but not with 5-year distant recurrence-free survival or disease-specific survival.

CONCLUSIONS

Preoperative XRT combined with complete R0/R1 resection for unifocal, primary RP-LPS was associated with improved LR and it should be considered in the multimodality treatment of RP-LPS. J. Surg. Oncol. 2016;114:814-820. © 2016 2016 Wiley Periodicals, Inc.

Predictors of improved survival for patients with retroperitoneal sarcoma

BACKGROUND

Retroperitoneal sarcomas are rare tumors that can be locally aggressive with high rates of recurrence. Given that data on survival in patients with retroperitoneal sarcomas are conflicting, we sought to use a nationwide cancer database to identify factors associated with survival in patients with retroperitoneal sarcomas.

METHODS

The Surveillance, Epidemiology, and End Results database was utilized to identify patients with retroperitoneal sarcomas from 2002 to 2012. Univariable and multivariable survival analysis was performed using a generalized gamma parametric survival function.

RESULTS

A total of 2,920 patients were included; overall 5- and 10-year survivals were 58.4% and 45.3%, respectively. On multivariable survival analysis, age, histologic type, grade, size, local extension, lymph node, and distant metastasis were associated with decreased survival (all P < .05). Patients undergoing operative resection survived 2.5 times longer (95% confidence interval: 2.0-3.0, P < .001) and those receiving radiation therapy 1.3 times longer (95% confidence interval: 1.1-1.6, P = .001), respectively.

CONCLUSION

During the past decade, retroperitoneal sarcoma patients treated with radiation demonstrate longer survival compared with patients who did not receive radiation. Further study is needed to fully elucidate the mechanisms that underlie the radiation-related survival benefit observed in this study.

Liposarcoma: Multimodality Management and Future Targeted Therapies

There are 3 biologic groups of liposarcoma: well-differentiated and dedifferentiated liposarcoma, myxoid/round cell liposarcoma, and pleomorphic liposarcoma. In all 3 groups, complete surgical resection is central in treatment aimed at cure and is based on grade. Radiation can reduce risk of local recurrence in high-grade lesions or minimize surgical morbidity in the myxoid/round cell liposarcoma group. The groups differ in chemosensitivity, so adjuvant chemotherapy is selectively used in histologies with metastatic potential but not in the resistant subtype dedifferentiated liposarcoma. Improved understanding of the genetic aberrations that lead to liposarcoma initiation is allowing for the rapid development of targeted therapies for liposarcoma.

Combined sunitinib and radiation therapy for preoperative treatment of soft tissue sarcoma: results of a phase I trial of the German interdisciplinary sarcoma group (GISG-03)

Background

Experimental data demonstrated that concurrent anti-angiogenic treatment with sunitinib may improve the efficacy of radiation therapy (RT). Here we report the results of a phase I trial performed within the German Interdisciplinary Sarcoma Group (GISG-03) of combined sunitinib and RT for neoadjuvant treatment of locally advanced soft tissue sarcoma (STS).

Methods

The primary endpoint of the study was to explore the recommended dose of sunitinib combined with RT for subsequent trials. Treatment response, postoperative complications after tumor resection and toxicity according to CTCAE 4.0 were secondary endpoints. The study used a 3 + 3 design. Patients received either 25 mg (dose level 1) or 37.5 mg (dose level 2) sunitinib two weeks prior to and throughout RT (28 × 1.8 Gy). Surgery was scheduled 5–8 weeks after completion of neoadjuvant treatment. Study registration: NCT01498835.

Results

Six patients were enrolled in dose level 1 and three patients in dose level 2. Median tumor size was 11 cm. Tumors were located in the retroperitoneum (4/9), lower leg (3/9) or trunk (2/9). At dose level 1, 1/6 patients developed dose limiting lymphopenia. At dose level 2, no patient developed dose limiting toxicity. Most frequent toxicities were hematological (8/9) and oral (5/9). Dose adjustments of sunitinib were necessary in 5/9 patients. All patients received full dose RT and underwent tumor resection (8/9 R0 and 1/9 R1). Local toxicity of RT did not exceed Grade 2. 2/9 patients had postoperative complications requiring re-intervention. Treatment response according to RECIST was as follows: partial response 1/9, stable disease 7/9, and progressive disease 1/9. Pathological examination revealed ≥ 95 % tumor necrosis in 3/9 resected specimens.

Conclusions

Combined sunitinib and RT was tolerable as neoadjuvant treatment for locally advanced STS patients regardless of tumor localization. The recommended sunitinib dose for subsequent trials is 37.5 mg.

Long-term outcomes in treatment of retroperitoneal sarcomas: A 15 year single-institution evaluation of prognostic features

BACKGROUND

Retroperitoneal sarcomas are connective tissue tumors arising in the retroperitoneum. Surgical resection is the mainstay of treatment. Debate has arisen over extent of resection, changes in histological classification/grading, and interest in incorporating radiotherapy. Therefore, we reviewed our institution's experience to evaluate prognostic factors.

METHODS

Retrospective chart review of all primary RPS patients at Johns Hopkins Hospital from 1994 to 2010. Histologic diagnosis and grading were re-evaluated with current criteria. Prognostic factors for survival, and recurrence were assessed.

RESULTS

One hundred thirty-one primary RPS patients met inclusion criteria. Median survival for patients who undergo en-bloc resection to negative margins (R0/R1) is 81.7 months. Surgical margins and grade were the most important factors for survival along with age, gender, presence of metastases and resection of ≥5 organs. Five-year survival for R0/R1 resection was 60%, similar to compartmental resection. Radiotherapy significantly decreased local recurrence (P = 0.026) on multivariate analysis. Grade in leiomyosarcomas and dedifferentiation in liposarcomas dictated patterns of local versus distal recurrence.

CONCLUSIONS

En bloc surgical resection to R0/R1 margins remains the cornerstone of therapy and provides comparable outcomes to compartmental resections. Grade remains important for prognosis, and histology dictates recurrence patterns. Radiotherapy appears promising for local control and warrants further investigation. J. Surg. Oncol. 2016;114:56-64. © 2016 Wiley Periodicals, Inc.

Is long-term survival possible after margin-positive resection of retroperitoneal sarcoma (RPS)?

BACKGROUND/OBJECTIVES

For various reasons, some patients undergo a gross margin positive resection (R2) leading to a dilemma in care. We hypothesized that there is a subset of patients who have long-term survival (LTS, ≥5 years) after R2 resection for retroperitoneal sarcoma (RPS).

METHODS

National Cancer Database data from 1998 to 2011 were reviewed to identify patients with RPS who had R2 resections. Logistic and Cox regression models were used to compare LTS with short-term survival.

RESULTS

Of 12,028 patients, R2 resection rate was 3.28% (4.9% in 1998; 2.5% in 2011). Median survival for RPS with R2 resection was 21 months versus 69 months for those with R0/R1 resections (P < 0.001). Of 272 patients with available survival, 24% (n = 64) survived ≥5 years with 64% alive at follow-up. LTS was most often seen in younger patients (<65 years) with well-differentiated liposarcoma. Chemotherapy appeared to improve survival in the first 3 postoperative years, but paradoxical effects were seen in LTS (Hazards Ratio [HR] 0.69, 95%CI: 0.50-0.95, P = 0.024) in first 3 years versus (HR 2.15, 95%CI: 1.21-3.81, P = 0.009).

CONCLUSION

Long-term survival is possible for a subset of patients after an R2 resection for RPS, especially with favorable histology characteristics. Benefits of chemotherapy in margin positive settings need to be investigated. J. Surg. Oncol. 2016;113:823-827. © 2016 Wiley Periodicals, Inc.

Neoadjuvant radiotherapy for retroperitoneal sarcoma: A systematic review

BACKGROUND AND OBJECTIVES

The multi-modal treatment of retroperitoneal sarcoma has seen increased use of neoadjuvant radiation. However, its effect on local recurrence and survival remain controversial. We aimed to synthesize and evaluate the literature.

METHODS

The review was conducted according the recommendation of the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) group with pre-specified inclusion and exclusion criteria.

RESULTS

Of 8,701 citations collected, 15 articles reported on 464 patients. The median age was 56 years (45-64). The predominant histological subtypes were liposarcoma (51.54%) and leiomyosarcoma (23.26%). Tumor differentiation composed of 37.1% well-, 12.8% moderate-, 46.0% poorly-, and 4.1% undifferentiated. Most studies featured external beam radiation therapy (EBRT) treatment regimen with some who included patients treated with IMRT instead. Median follow-up averaged 41.4 months (19-106 months). Median 5-year OS, PFS, and LRR rates were 58%, 71.5%, and 25%. Using the NCI CTCAE, toxicities from Grade 1 (Mild) through Grade 5 (death) were experienced by 18.8%, 10.2%, 16.3%, 0.7%, and 1.6% of patients.

CONCLUSIONS

NART is a safe to use for RPS, but its effect toward survival and local control remains unclear. Without randomized control trials, common reporting criteria for pro- and retrospective studies are needed to allow comparison between studies. J. Surg. Oncol. 2016;113:628-634. © 2016 Wiley Periodicals, Inc.

The role of radiotherapy in the management of localized soft tissue sarcomas

The combination of radiotherapy (RT) and function-preserving surgery is the most usual contemporary approach in the management of soft tissue sarcomas (STS). Pre- and postoperative RT result in similar local control rates, as shown by a landmark trial in extremity STS. In this review, the role of RT in the management of extremity STS will be discussed, but STS in other sites, including retroperitoneal STS, will also be addressed. The focus will consider various aspects of RT including strategies to reduce the volume of tissue being irradiated, dose, scheduling, and the possible of omission of RT in selected cases. Finally, technology advances through the use of intensity-modulated radiotherapy (IMRT), image-guided IMRT, intraoperative radiotherapy (IORT) and particle therapy will also be discussed.

The importance of surgical margins in retroperitoneal sarcoma

Surgery is the "gold-standard" treatment for retroperitoneal sarcomas, but local recurrence is common, and can cause disease-related death. Complete gross resection is associated with improved survival, but debate exists as to whether resection of adjacent organs to improve margins or prescription of neoadjuvant radiation leads to better outcomes. This review summarizes data addressing prognostic value of margin, extent of surgery necessary to optimize treatment of retroperitoneal sarcomas, and role of histology in optimizing therapy.

Texture Analysis of Non-Contrast-Enhanced Computed Tomography for Assessing Angiogenesis and Survival of Soft Tissue Sarcoma

OBJECTIVE

To evaluate the role of computed tomographic (CT) texture analysis in assessing tumor angiogenesis and survival of soft tissue sarcoma (STS).

METHODS

In 20 patients with STSs, tumor texture parameters, which were measured on pretherapeutic CT using CT texture analysis software with the spatial scale filter extracting fine to coarse texture, were compared with microvessel density, plasma vascular endothelial growth factor (VEGF), soluble VEGF receptor-1, and overall survival (OS).

RESULTS

Mean of positive pixels (MPP) showed a positive correlation with microvessel density (P = 0.02). Entropy at medium texture scales (spatial scale filter = 3, 4, 5) showed positive correlations with VEGF (P = 0.03, P = 0.009, and P = 0.02, respectively), and entropy without filtration showed a positive correlation with soluble VEGF receptor-1 (P = 0.02). In the univariate analysis, kurtosis at a medium texture scale and MPP showed significant correlations with OS (P = 0.04 and P = 0.007), and multivariate analysis demonstrated that MPP was an independent prognostic factor (P = 0.01).

CONCLUSION

Texture parameters are associated with tumor angiogenesis and OS in STS.

Comparison of Perioperative Radiation Therapy and Surgery Versus Surgery Alone in 204 Patients With Primary Retroperitoneal Sarcoma: A Retrospective 2-Institution Study

OBJECTIVE

To compare outcomes of patients with retroperitoneal or pelvic sarcoma treated with perioperative radiation therapy (RT) versus those treated without perioperative RT.

BACKGROUND

RT for retroperitoneal or pelvic sarcoma is controversial, and few studies have compared outcomes with and without RT.

METHODS

Prospectively maintained databases were reviewed to retrospectively compare patients with primary retroperitoneal or pelvic sarcoma treated during 2003-2011. Multivariate Cox regression models were used to assess associations with the primary endpoints: local recurrence-free survival (LRFS) and disease-specific survival.

RESULTS

At 1 institution, 172 patients were treated with surgery alone, whereas at another institution 32 patients were treated with surgery and perioperative proton beam RT or intensity-modulated RT with or without intraoperative RT. The groups were similar in age, tumor size, grade, and margin status (all P > 0.08). The RT group had a higher percentage of pelvic tumors (P = 0.03) and a different distribution of histologies (P = 0.04). Perioperative morbidity was higher in the RT group (44% vs 16% of patients; P = 0.004). After a median follow-up of 39 months, 5-year LRFS was 91% (95% confidence interval, 79%-100%) in the RT group and 65% (57%-74%) in the surgery-only group (P = 0.02). On multivariate analysis, RT was associated with better LRFS (hazard ratio, 0.26; P = 0.03). Five-year disease-specific survival was 93% (95% confidence interval, 82%-100%) in the RT group and 85% (78%-92%) in the surgery-only group (P = 0.3).

CONCLUSIONS

The addition of advanced-modality RT to surgery for primary retroperitoneal or pelvic sarcoma was associated with improved LRFS, although this did not translate into significantly better disease-specific survival. This treatment strategy warrants further investigation in a randomized trial.

Long-term Oncologic Outcomes After Neoadjuvant Radiation Therapy for Retroperitoneal Sarcomas

OBJECTIVE

To evaluate long-term survival among patients undergoing radiation therapy (RT), followed by surgical resection of retroperitoneal sarcomas (RPS).

BACKGROUND

Despite a lack of level 1 evidence supporting neoadjuvant RT for RPS, its use has increased substantially over the past decade.

METHODS

The 1998-2011 National Cancer Data Base was queried to identify patients who underwent resection of RPS. Subjects were grouped by use of neoadjuvant RT. Perioperative variables and outcomes were compared. Multivariable logistic regression was performed to assess predictors of neoadjuvant RT. Groups were propensity matched using a 2:1 nearest neighbor algorithm and short-term outcomes were compared. Finally, long-term survival was evaluated using the Kaplan-Meier method, with comparisons based on the log-rank test.

RESULTS

A total of 11,324 patients were identified. Neoadjuvant RT was administered to 696 patients (6.1%). During the study period, preoperative RT use increased from 4% to nearly 15%. Male sex, tumor size larger than 5 cm, treatment at an academic/research program, and higher tumor grade all predicted neoadjuvant RT administration. After propensity matching, the only difference in baseline characteristics was the use of neoadjuvant chemotherapy. Although neoadjuvant RT was associated with a higher rate of negative margins (77.5% vs 73.0%; P = 0.014), there was no corresponding improvement in 5-year survival (53.2% vs 54.2%; P = 0.695).

CONCLUSIONS

Despite the increasing use of neoadjuvant RT for patients with RPS, the survival benefit associated with this treatment modality remains unclear. Continued investigation is needed to better define the role of RT among patients with RPS.

Combined radiation therapy and sunitinib for preoperative treatment of soft tissue sarcoma

BACKGROUND

Antiangiogenic substances and radiation therapy (RT) may have synergistic effects and improve irradiation efficacy. We present a cohort study evaluating the toxicity of combined sunitinib and RT as neoadjuvant treatment of extremity and retroperitoneal soft tissue sarcoma (STS).

METHODS

Sixteen patients with locally advanced extremity (6/16) or retroperitoneal (10/16) STS were treated with continuous-dosing sunitinib (15/16: 37.5 mg daily; 1/16: 25 mg daily) and standard RT (45-50.4 Gy) preoperatively. Surgery was scheduled 5-9 weeks following neoadjuvant treatment. The primary goal of the study was to determine combined treatment toxicity according to the Common Terminology Criteria for Adverse Events. Secondary goals were the evaluation of postoperative morbidity and treatment response.

RESULTS

Eight of 16 patients developed grade 3, and one patient developed grade 4, hematological toxicity. One patient experienced grade 3 hand-foot syndrome. The most frequent treatment toxicities of any grade were hematological (15/16) or dermatological (9/16). Three patients had partial response, 11 had stable disease, and 2 had progressive disease according to Response Evaluation Criteria in Solid Tumors (RECIST). Fourteen of 16 patients underwent surgery; tumors were not removed in two patients because of patient refusal or intercurrent metastatic disease. The proportion of tumor necrosis exceeded 90 % in 5 of 14 patients, and 4 patients had postoperative complications requiring reintervention.

CONCLUSIONS

Preoperative treatment with concurrent sunitinib and RT was tolerable, and postoperative morbidity did not increase. Combined treatment with RT and sunitinib was also feasible in patients with retroperitoneal STS, and warrants further investigation.

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.

Retroperitoneal Sarcoma Target Volume and Organ at Risk Contour Delineation Agreement Among NRG Sarcoma Radiation Oncologists

PURPOSE

The purpose of this study was to evaluate the variability in target volume and organ at risk (OAR) contour delineation for retroperitoneal sarcoma (RPS) among 12 sarcoma radiation oncologists.

METHODS AND MATERIALS

Radiation planning computed tomography (CT) scans for 2 cases of RPS were distributed among 12 sarcoma radiation oncologists with instructions for contouring gross tumor volume (GTV), clinical target volume (CTV), high-risk CTV (HR CTV: area judged to be at high risk of resulting in positive margins after resection), and OARs: bowel bag, small bowel, colon, stomach, and duodenum. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics.

RESULTS

Ten radiation oncologists contoured both RPS cases, 1 contoured only RPS1, and 1 contoured only RPS2 such that each case was contoured by 11 radiation oncologists. The first case (RPS 1) was a patient with a de-differentiated (DD) liposarcoma (LPS) with a predominant well-differentiated (WD) component, and the second case (RPS 2) was a patient with DD LPS made up almost entirely of a DD component. Contouring agreement for GTV and CTV contours was high. However, the agreement for HR CTVs was only moderate. For OARs, agreement for stomach, bowel bag, small bowel, and colon was high, but agreement for duodenum (distorted by tumor in one of these cases) was fair to moderate.

CONCLUSIONS

For preoperative treatment of RPS, sarcoma radiation oncologists contoured GTV, CTV, and most OARs with a high level of agreement. HR CTV contours were more variable. Further clarification of this volume with the help of sarcoma surgical oncologists is necessary to reach consensus. More attention to delineation of the duodenum is also needed.

Management of patients with retroperitoneal tumors and a review of the literature

Background

Retroperitoneal tumors (RTs) develop insidiously and are generally seen as large masses, and 50% of RTs are larger than 20 cm at the time of diagnosis. In this article, we share our experience of 5 years of surgical management of RTs.

Methods

We evaluated 28 RT cases operated on in three education hospitals in Turkey from January 2008 onwards, with regard to patients’ demographic characteristics, complaints, weight loss figures, the location and size of the tumor, blood transfusion, intra-operational time, metastases (in malignant cases), additional organ resection, histological grade, local recurrences, average life expectancy, and post-operative treatment methods.

Results

The mean age of the patients was 49 years (range, 18 to 78 years). Twenty (71.43%) were female, and 8 (28.57%) were male. The primary complaint was abdominal pain in 18 patients (64.28%). CT scans were performed in 17 (61%) patients, 10 (35.4%) underwent abdominal MR imaging, and 1 (3.6%) underwent both abdominal CT and abdominal MR imaging. A mass was palpated in the pelvis (suprapubic region) in seven (25%) of the patients during physical examination. The largest tumors were detected in the left lumbar area. The mean tumor size was 12.78 cm (range, 2 to 30 cm). The mean intra-operational time was 192 min (range, 70 to 380 min). The mean hospitalization period was 11 days (range, 8 to 23 days). Seven (25%) patients were reported to have benign tumors, while 21 (75%) were reported to have malignant tumors. The most frequently seen malignant pathology was liposarcoma (eight cases; 38.09%) followed by leiomyosarcoma (five cases; 23.8%) and malignant fibrous histiocytoma (four cases; 19.04%). The earliest local recurrence was detected in the 12th month and the latest in the 28th month. A total of 11 (52.3%) of the total of 21 malignant cases experienced local recurrence within 3 years. The 3-year average life expectancy was 85.7% in the 18 malignant cases.

Conclusions

Due to the low response rate of all but two types of RT to chemotherapy, the best remaining treatment option is surgery with wide resection margins, whereby all macroscopic traces of tumor are removed.

Giant retroperitoneal liposarcoma: Case report and review of the literature

AIM

Retroperitoneal soft-tissue sarcomas are relatively uncommon diseases, the most frequent histotype, ranging from 20% to 45% of all cases, is represented by liposarcoma, which is a hard-to treat condition for its local aggressiveness and clinical aspecificity.

PRESENTATION OF CASE

We report a case of a 64-years-old woman who underwent surgical resection for a giant pleomorphic retroperitoneal liposarcoma.

DISCUSSION

Currently chemotherapy for retroperitoneal soft-tissue sarcomas is no effective, and radiotherapy has limited efficacy due to the toxicity affecting adjacent intra-abdominal structures, showed validity only in case of high-grade malignancy by reducing local recurrence, but with no advantage in overall survival. Nowadays only, the complete surgical resection remains the most important predictor of local recurrence and overall survival.

CONCLUSION

The removal of a retroperitoneal sarcoma of remarkable size is a challenge for the surgeon owing to the anatomical site, to the absence of an anatomically evident vascular-lymphatic peduncle and to the adhesions contracted with the contiguous organs and with the great vessels. Therefore, we believe that, particularly for large-size diseases associated to high-grade malignancy, a complete surgical resection with removal of the contiguous intra and retroperitoneal organs when infiltrated represents the only therapeutic option to obtain a negative margin and therefore an oncological radicality.