What are risk factors for local recurrence of deep high-grade soft-tissue sarcomas?

Local recurrence rates of superficial versus deep soft tissue sarcoma

INTRODUCTION

Soft tissue sarcomas are a group of malignancies that commonly occur in the extremities. As deep lesions may exist within the confines of the muscular fascia, we postulate that local recurrence rates are higher for superficial soft tissue sarcomas managed by the standard of care.

MATERIALS AND METHODS

A retrospective review was performed on 90 patients who underwent surgical resection of soft tissue sarcomas of the extremity from 2007 to 2015. Patients with minimum 2-year follow-up and adequate operative, pathologic, and clinical outcomes data were included.

RESULTS

Mean age was 54 ± 18 years with 49 (54.4%) patients being male. Lesions in 77.8% of cases were deep, and 22.2% were superficial to fascia. Following the index surgical resection, a total of 33 (36.7%) patients had positive margins. A total of 17 (18.9%) patients had a local recurrence. Overall, 3-year survival was 92.7%, and 5-year survival was 79.0%. Five-year recurrence-free survival of deep sarcomas was 91.1% versus 58.2% of superficial lesions (p = 0.006). Patients with higher tumor depth had lower odds of experiencing a local recurrence (HR 0.26 [95% CI 0.09-0.72]). Local recurence rates was also associated with positive surgical margins on initial resection (33.3% versus 12.3%) (p = 0.027).

CONCLUSIONS

In this series, superficial tumor depth was associated with local recurrence of soft tissue sarcomas of the extremity following surgical resection. Positive surgical margins was also associated with local recurrence.

MRI of Soft-Tissue Tumors: What to Include in the Report

MRI serves as a critical step in the workup, local staging, and treatment planning of extremity soft-tissue masses. For the radiologist to meaningfully contribute to the management of soft-tissue masses, they need to provide a detailed list of descriptors of the lesion outlined in an organized report. While it is occasionally possible to use MRI to provide a diagnosis for patients with a mass, it is more often used to help with determining the differential diagnosis and planning of biopsies, surgery, radiation treatment, and chemotherapy (when provided). Each descriptor on the list outlined in this article is specifically aimed to assist in one or more facets of the overall approach to soft-tissue masses. This applies to all masses, but in particular sarcomas. Those descriptors are useful to help narrow the differential diagnosis and ensure concordance with a pathologic diagnosis and its accompanying grade assignment of soft-tissue sarcomas. These include a lesion's borders and shape, signal characteristics, and contrast enhancement pattern; the presence of peritumoral edema and peritumoral enhancement; and the presence of lymph nodes. The items most helpful in assisting surgical planning include a lesion's anatomic location, site of origin, size, location relative to a landmark, relationship to adjacent structures, and vascularity including feeding and draining vessels. The authors provide some background information on soft-tissue sarcomas, including their diagnosis and treatment, for the general radiologist and as a refresher for radiologists who are more experienced in tumor imaging. ©RSNA, 2024 See the invited commentary by Murphey in this issue.

Multiple Flap Transfer for Multiple Local Recurrence of Soft Tissue Sarcoma

Background and Objectives: Surgical management of local recurrence of soft tissue sarcomas (STS) is still challenging. In this article, we report on multiple flap reconstructions for multiple local recurrences of STS. Their feasibility will be validated by examining clinical cases. Materials and Methods: Patients who underwent multiple flap reconstructions for multiple local recurrences of STS between April 1997 and October 2021 were included in this retrospective study. Patient demographics, tumor characteristics, surgical characteristics, and postoperative complications were examined. Results: Twenty operations of eight patients were identified. The location of the defects was the back in two, the buttock in two, the groin in two, and the lower extremities in two. The average total number of wide resections was 4.0 and the average total number of flap reconstructions was 2.5. The average follow-up period was 109.4 months. The average size of the defect was 102.4 cm2 and the average flap size was 15.7 × 10.8 cm. The histological diagnoses were malignant fibrous histocytoma (MFH) in eight operations, osteosarcoma in two operations, myxoid liposarcoma in two operations, undifferentiated pleomorphic sarcoma (UPS) in six operations, and myxofibrosarcoma (MFS) in one operation. Of twelve subsequent operations, the resection of the previously transferred flap was performed in six operations (50%). The occurrence of take back, flap complications, and donor-site complications in the primary operation group was 25%, 25%, and 12.5%, respectively. The occurrence of take back, flap complications, and donor-site complications in the second and subsequent operation group was 0%, 0%, and 16.7%, respectively. Conclusions: Multiple operations including wide resections followed by flap reconstructions for multiple local recurrences are feasible. Reconstructive surgeons should choose the options of the flaps considering the future local recurrence for tumors with a high risk of recurrence.

Factors associated with complications after resection of soft tissue sarcomas of the groin

INTRODUCTION

Soft tissue sarcomas (STS) are rare malignant tumors that require regimented treatment at designated cancer centers. The surgical care of groin tumors is difficult because of frequent local complications. Few studies have been done on prognostic factors and complications. This led us to conduct a retrospective study to: (1) identify factors associated with local postoperative complications during the surgical care of primary groin STS; (2) identify the factors associated with delayed adjuvant radiation therapy; (3) define the optimal surgical treatment strategy to allow adjuvant treatments to start as early as possible, if applicable.

HYPOTHESIS

We hypothesized that certain patients presenting with an STS of the groin or inguinal area are at higher risk of complications.

MATERIALS AND METHODS

This retrospective single-center study included all the patients admitted to our referral sarcoma center between 1995 and 2016 for the resection of a primary STS of the groin. Major complications were defined as surgical revision, an invasive procedure, or prolonged dressing use.

RESULTS

Of the 55 included patients, 13 suffered major complications (24%) of which 10 were surgical revisions, two were repeated aspirations and one was prolonged dressing use. Among the 10 surgical revisions, there were two pedicled salvage flaps. The patients who suffered major complications were significantly more likely to be smokers than the patients who did not have major complications (31% vs 2% (p=0.002)). Obesity and surgical bone exposure were most often associated with complications but not significantly (23% vs 5%, p=0.053 and 38% vs 14% (p=0.057), respectively). Of the 39 patients (71%) who needed postoperative radiation therapy, 5 patients (13%) had it delayed, and 3 patients (8%) did not receive any at all due to major complications.

CONCLUSION

In our study, smoking was associated with the occurrence of major complications after groin STS resection and there was a strong trend for obesity and surgical bone exposure. Major complications were associated with a delay in starting postoperative radiation therapy. Thus, we recommend flap coverage after tumor resection in patients who have factors known to contribute to complications.

LEVEL OF EVIDENCE

IV, Retrospective study.

Management of musculoskeletal tumours of the extremity in low-resource settings

BACKGROUND

Management of extremity tumor is particularly challenging in low-resource settings where patients are often referred with late presentations. First, diagnostic means are limited, with CT scan, MRI, and pathology usually not being available. Limitations are also related to therapeutic means, as the absence of adjuvant therapy (chemotherapy and radiotherapy) may preclude any improvement in overall survival despite a curative surgical treatment.

OBJECTIVE

The authors suggest a kind of "toolbox" combining a diagnostic guide, based on clinical examination and X-rays, and therapeutic advice adapted to this context of care. The objective is to help the surgeon to better categorize the tumor to decide whether or not to operate or act in a relevant way.

CONCLUSION

The authors do not aim to provide recommendations but rather an inventory of what the isolated surgeon should know to decide on the best treatment strategy which, however, can only be symptomatic.

Margin Assessment in Soft Tissue Sarcomas: Review of the Literature

Simple Summary

Many classifications to assess margins status for soft tissue sarcomas are reported in the literature. Most of the series are heterogeneous and variable in size, making it difficult to compare results from study to study. Thus, which is the best way to assess margins in order to predict the risk of local recurrence is still debated. The aim of this narrative review is to provide a comprehensive assessment of the literature on margins, and to highlight the need for a uniform description of the margin status for patients with soft tissue sarcomas (STS).

Abstract

Adequacy of margins must take into consideration both the resection margin width (quantity) and anatomic barrier (quality). There are several classification schemes for reporting surgical resection margin status for soft tissue sarcomas (STS). Most of the studies regarding treatment outcomes in STS included all histologic grades and histological subtypes, which include infiltrative and non-infiltrative subtypes and are very heterogeneous in terms of both histologic characteristics and treatment modalities (adjuvant treatments or not). This lack of consistency makes it difficult to compare results from study to study. Therefore, there is a great need for evidence-based standardization concerning the width of resection margins. The aim of this narrative review is to provide a comprehensive assessment of the literature on margins, and to highlight the need for a uniform description of the margin status for patients with STS. Patient cases should be discussed at multidisciplinary tumor boards and treatments should be individualized to clinical and demographic characteristics, which must include also a deep knowledge of specific histotypes behaviors, particularly infiltrative ones.

Indications of amputation after limb-salvage surgery of patients with extremity-located bone and soft-tissue sarcomas: A retrospective clinical study

OBJECTIVE

This study aimed to investigate amputation-related factors after limb-salvage surgery (LSS) in patients with extremity-located bone and soft-tissue sarcomas and determine the relationship between these factors and patient survival.

METHODS

In this retrospective study at our institution, patients in whom LSS was first performed because of an extremity-located musculoskeletal sarcoma, and subsequently amputation was carried out for various indications were included. Patient and tumor characteristics, details of surgical procedures, indications of amputation, number of operations, presence of metastasis before amputation, and post-amputation patient survival rates were analyzed.

RESULTS

A total of 25 patients (10 men, 15 women; mean age=41.96±21.88 years), in whom amputation was performed after LSS as initial resection of an extremity sarcoma or re-resection(s) of a local recurrence, were included in the study. The leading oncological indication for amputation was local recurrence that occurred in 18 (72%) patients. Non-oncological indications included prosthetic infection in 5 (20%), mechanical failure in 1 (4%), and skin necrosis in 1 (4%) patient. The patients underwent a median of 2 (range, 1-4) limb-salvage procedures before amputation. Distant organ metastasis was detected in 22 (88%) patients during follow-up; in 13 (52%) of these patients, metastasis was present before amputation. A total of 11 (44%) patients were alive at the time of study with no evidence of the disease (n=3) or with disease (n=8), and 14 (56%) patients died of disease. The mean overall and post-amputation survival were 47±20.519 (range, 11-204) months and 22±4.303 (range, 2-78) months, respectively. The median follow-up was 27 (range, 6-125) months.

CONCLUSION

The most common causes of amputation after LSS were local recurrence and prosthetic infection. Patients who underwent amputation after LSS developed a high rate of distant organ metastasis during follow-up and had reduced survival.

LEVEL OF EVIDENCE

Level IV, Therapeutic Study.

Soft Tissue Sarcoma Follow-up Imaging: Strategies to Distinguish Post-treatment Changes from Recurrence

Soft tissue sarcomas encompass multiple entities with differing recurrence rates and follow-up intervals. The detection of recurrences and their differentiation from post-therapeutic changes is therefore complex, with a central role for the clinical radiologist. This article describes approved recommendations. Prerequisite is a precise knowledge of the current clinical management and surgical techniques. We review recurrence rates and treatment modalities. An adequate imaging technique is paramount, and comparison with previous imaging is highly recommended. We describe time-dependent therapy-related complications on magnetic resonance imaging compared with the spectrum of regular post-therapeutic changes. Early complications such as seromas, hematomas, and infections, late complications such as edema and fibrosis, and inflammatory pseudotumors are elucidated. The appearance of recurrences and radiation-associated sarcomas is contrasted with these changes. This systematic approach in follow-up imaging of soft tissue sarcoma patients will facilitate the differentiation of post-therapeutic changes from recurrences.

The role of surgical margin quality in myxofibrosarcoma and undifferentiated pleomorphic sarcoma

OBJECTIVES

The effect of margin quality as a barrier against infiltration of soft-tissue sarcomas (STSs) has been unclear. We aimed to investigate the effect of margin quantity and quality on local control for myxofibrosarcoma (MFS) and undifferentiated pleomorphic sarcoma (UPS).

METHODS

278 patients with a localised MFS and UPS were studied. Margin quality was categorized into five types; type 1, pseudocapsule/reactive zone; type 2, fat/fibrofatty tissue; type 3, muscle; type 4, fascia; type 5, periosteum.

RESULTS

The 5-year cumulative LR incidence was 22% and 13% in patients with positive and 0.1-9.9 mm margins, respectively, but decreased to 3% with ≥10.0 mm margins (p = 0.009); the cumulative LR incidence was significantly lower in patients with ≥10.0 mm margins than those with positive margins (p = 0.033) but was not significantly different in those with 0.1-9.9 mm margins (p = 0.183). In patients with 0.1-9.9 mm margins, the cumulative LR incidence was affected by margin quality; type 4 and 5 provided an LR risk less than 5% (p < 0.001), which was similar to those with margins ≥10.0 mm. Combining these two factors together, the LR risk in patients with positive or 0.1-9.9 mm margins without fascia/periosteum was approximately 11 × higher than patients with 0.1-9.9 mm margins with fascia/periosteum or margins ≥10.0 mm (p = 0.002).

CONCLUSIONS

A resection margin of 0.1-9.9 mm with fascia or periosteum provided a similar LR risk profile to ≥10 mm margins with any margin quality, which provided the lowest LR risk. The quality of fascial or periosteal tissue margins may be equivalent to a margin quantity of 10 mm as a barrier to LR.

The Effect of Resection Margin on Local Recurrence and Survival in High Grade Soft Tissue Sarcoma of the Extremities: How Far Is Far Enough?

Simple Summary

In soft tissue sarcomas the width of surgical margins after resection determines the extent of surgery and the function after resection. But how far is really necessary? 305 patients with deep-seated, G2/3 soft tissue sarcomas of the extremity, the trunk wall, or the pelvis were reviewed. The 5-year local recurrence-free survival (LRFS) was 82%. Overall survival (OS) at 5 years was 66%. Positive (contaminated) margins worsened LRFS and OS. A margin of >10 mm did not improve LRFS and OS as compared to one of >5 mm. A resection margin of <1 mm showed a trend but not significantly better LRFS or OS compared to a contaminated margin. In conclusion the margin should at least be free of tumor, in sound tissue. A margin of >5 mm sound tissue seems to be sufficient. Resecting more tissue does not benefit the patient.

Abstract

Background: The significance of surgical margins after resection of soft tissue sarcomas in respect to local-recurrence-free survival and overall survival is evaluated. Methods: A total of 305 patients with deep-seated, G2/3 soft tissue sarcomas (STS) of the extremity, the trunk wall, or the pelvis were reviewed. The margin was defined according to the Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) classification system (R0-2), the Union Internationale Contre le Cancer (UICC) classification (R + 1 mm) for which a margin <1 mm is included into the R1 group, and in groups of <1 mm, 1–5 mm, >5 mm, or >10 mm. Results: Of these patients, 31 (10.2%) had a contaminated margin, 64 (21%) a margin of <1 mm, 123 (40.3%) a margin of 1–5 mm, 47 (15.4%) a margin of >5 mm, and 40 (13.1%) a margin of >10 mm. The 5-year local recurrence-free survival (LRFS) was 81.6%. Overall survival (OS) at 5 years was 65.9%. Positive margins worsened LRFS and OS. A margin of >10 mm did not improve LRFS and OS as compared to one of >5 mm. Conclusions: A resection margin of <1 mm showed a trend but not significantly better LRFS or OS compared to a contaminated margin. This finding supports use of the UICC classification. A margin of more than 10 mm did not improve LRFS or OS.

Oncologic safety of propeller flap and free flap in reconstruction after soft tissue sarcoma resection

BACKGROUND AND OBJECTIVES

The propeller flap is a reliable option for reconstruction after soft tissue sarcoma resection. However, some parts of the resection margin may move away from its original position during flap rotation and thus can be excluded from the clinical target volume of adjuvant radiotherapy. This study aimed to evaluate local recurrence after soft tissue sarcoma resection with propeller flap or free flap reconstruction.

METHODS

Patients who underwent resection of soft tissue sarcoma followed by a free flap or propeller flap reconstruction and adjuvant radiotherapy at a single institution were retrospectively reviewed.

RESULTS

The 1- and 3-year local control rates were 94.6% and 88.6% in the free flap group vs 90.6% and 87.5% in the propeller flap group, without statistical significance. There were no statistically significant differences in 5-year local recurrence-free survival (88.6% vs 87.5%) and disease-free survival (82.5% vs 74.8%) between the groups.

CONCLUSIONS

Although there was no significant difference in local control and disease-free survival rates between propeller flap and free flap reconstruction after soft tissue sarcoma resection, a multidisciplinary approach is needed to obtain surgical information for determining the accurate clinical target volume of adjuvant radiotherapy and the area for meticulous follow-up postoperatively.

Low-grade soft-tissue sarcomas: What is an adequate margin for local disease control?

BACKGROUND

Whilst the resection margin is an established factor predictive of local control of soft-tissue sarcomas (STSs), the adequacy of margin width for low-grade STSs has been rarely described. We aimed to investigate the margin adequacy and its prognostic relevance in low-grade STSs.

METHODS

109 patients who underwent surgical treatment for a low-grade STS were studied. The prognostic value of margin status was evaluated according to the R-, R+1-classification, and width in millimetres.

RESULTS

The 10-year local recurrence (LR) rates were 6%, 27%, 54% in R0, R1, and R2, respectively (p < 0.001), according to the R-classification. The R+1-classification resulted in a decreased LR rate in R1, but no major differences in LR rates in R0 and R2; 7%, 14%, 54% in R0, R1, and R2, respectively (p < 0.001). When classified by metric distance, 10-year LR rates were 0%, 8%, and 38% by ≥ 2.0 mm, 0.1-1.9 mm, and 0 mm margins, respectively (p < 0.001). Patients with close margins (0.1-1.9 mm) who received adjuvant radiotherapy had a trend toward lower LR risk than those without radiotherapy (10-year, 4% vs. 12%; p = 0.406). The 5 and 10-year disease-specific mortality was 9% and 13%, respectively; margin width was not associated with disease-specific mortality but LR was a poor prognostic factor for survival (p = 0.003).

CONCLUSION

Whilst negative margin provided local control over 90%, excellent local control was achieved with microscopic margins ≥2 mm. The role of margins is more important than radiotherapy in local control. Margins do not determine survival, but LR is associated with a poor prognosis.

The adequacy of resection margin for non-infiltrative soft-tissue sarcomas

OBJECTIVES

There remains no consensus on what constitutes an adequate margin of resection for non-infiltrative soft-tissue sarcomas (STSs). We aimed to investigate the role of resection margins in millimetres for non-infiltrative STSs.

METHODS

502 patients who underwent surgical resection for a localized, non-infiltrative, high-grade STSs were studied. The prognostic significance of margin width was analysed and compared with the conventional R- and R+1-classification of surgical margins.

RESULTS

The overall local recurrence (LR) rate was 13%; 9% and 27% with negative and positive margins, respectively (p < 0.001). In patients with negative margins, the LR rates were greater than 10% in patients with margins ≤5.0 mm but reduced to less than 4% with margins >5.0 mm. When classified by the R- (or R+1)-classification, the 5-year cumulative LR incidence was 8%, 23% (16%), and 31% for R0, R1, and R2, respectively, which did not stratify the LR risk with negative margins. On the other hand, an accurate risk stratification was possible by metric distance; the 5-year cumulative incidence of LR was 29%, 10%, and 1% with 0 mm, 0.1-5.0 mm, and >5.0 mm, respectively (p < 0.001). This classification also stratified the LR risk in patients with or without adjuvant radiotherapy.

CONCLUSION

While a negative margin is essential to optimize local control in patients with non-infiltrative STSs, surgical margin width greater than 5 mm minimises the risk of local failure regardless of the use of adjuvant radiotherapy.

Desmoid tumor mimics local recurrence of extremity sarcoma on MRI

BACKGROUND AND OBJECTIVES

The development of desmoid fibromatosis after tumor resection may mimic local recurrence. To our knowledge, this phenomenon has not been reported after extremity sarcoma resection. We report four cases of desmoid-type fibromatosis ("desmoid tumors") mimicking local recurrence after extremity sarcoma resection.

METHODS

We retrospectively reviewed the records of patients treated for extremity sarcoma by our orthopedic oncology service from 2014 to 2019 and identified four patients with biopsy-proven desmoid tumors. We extracted clinical, pathologic, radiographic, and operative data for the primary neoplasms and desmoid tumors.

RESULTS

Four patients with postresection surveillance magnetic resonance imaging suspicious for local recurrence underwent further analysis showing desmoid tumors. Patients underwent image-guided needle biopsy, with specimens demonstrating fibromatosis-type histologic characteristics. Two cases were β-catenin positive. Desmoid tumors were managed with observation. No patient had experienced local or distant recurrence of the primary tumor at a mean follow-up of 30 months after resection (range, 23-34 months); none underwent surgery for symptoms of desmoid tumors.

CONCLUSIONS

Desmoid tumors should be considered part of the differential diagnosis when assessing patients with radiographic concern for postresection local recurrence of extremity bone and soft-tissue sarcoma. An image-guided needle biopsy can inform diagnosis and management.

Prediction of Soft Tissue Sarcoma from Clinical Characteristics and Laboratory Data

The accurate diagnosis of soft tissue tumors may be difficult. Simple clinical characteristics or laboratory data that can predict tumor malignancy can be useful tools for diagnosing soft tissue tumors. Between 2003 and 2018, 588 patients with primary soft tissue tumors were retrospectively reviewed. Their clinical characteristics and laboratory data were evaluated to determine their association with the diagnosis of benign, intermediate, or malignant tumor. Multivariable analysis revealed that tumor size ≥ 5.6 cm (odds ratio (OR), 6.15; p < 0.001), white blood cell (WBC) count ≥ 5700/µL (OR, 2.49; p = 0.002), hemoglobin (Hb) count ≤ 12.4 g/dL (OR, 2.56; p = 0.004), C-reactive protein (CRP) level ≥ 0.17 mg/dL (OR, 2.64; p < 0.001), and lactate dehydrogenase (LDH) level ≥ 240 IU/L (OR, 4.94; p < 0.001) were significant predictive factors for sarcoma. The sensitivity and specificity in the presence of three or more predictive factors for detecting malignant tumors were 0.58 and 0.90 respectively, and it was an appropriate threshold with the maximum Youden's index of 0.49. Simple clinical and laboratory data were useful tools for predicting whether the tumor is malignant. Patients with soft tissue tumors that meet any three or more predictive factors should be referred to a specialist.

Designing a Rational Follow-Up Schedule for Patients with Extremity Soft Tissue Sarcoma

PURPOSE

The risk of tumor recurrence after resection of soft tissue sarcoma (STS) necessitates surveillance in follow-up. The objective of this study was to determine the frequency/timing of metastasis and local recurrence following treatment for soft tissue sarcoma, and to use these data to justify an evidence-based follow-up schedule.

METHODS

Utilizing a prospective database, a retrospective single center review was performed of all patients with minimum 2-year follow-up after resection of a localized extremity STS. Kaplan-Meier estimates were used to calculate the incidence of local recurrence and metastases on an annual basis for 10 years.

RESULTS

We identified a total of 230 low-grade, 626 intermediate-grade and 940 high-grade extremity STS and a total of 721 events, 150 local recurrences and 571 metastases. Based on tumor size and grade, follow-up cohorts were developed that had similar metastatic risk. Using pre-determined thresholds for metastatic event, a follow-up schedule was established for each cohort.

CONCLUSION

Based on our results we recommend that patients with small low-grade tumors undergo annual follow-up for 5 years following definitive local treatment. Patients with large low-grade tumors, small intermediate-grade and small high-grade tumors should have follow-up every 6 months for the first 2 years, then yearly to 10 years. Only patients with large intermediate- or high-grade tumors require follow-up every 3 months for the first 2 years, then every 6 months for years 3-5, followed by annually until 10 years.

Sarcoma Surveillance: A Review of Current Evidence and Guidelines

After initial treatment of sarcoma, disease progression may occur in the form of local recurrence, pulmonary metastases, or extrapulmonary metastases. As such, surveillance is an important aspect of management, but no universally accepted practice standards are found. In the absence of strong evidence, and to allow for individualized care, existing guidelines contain flexibility in terms of both the frequency and modality of surveillance. In general, they agree that follow-up should be more intense in the early years after treatment, especially for high-grade sarcomas, and continue for at least 10 years. For local recurrence, data suggest that physical examination is usually sufficient for monitoring; in addition, some guidelines endorse imaging routinely, whereas others only as clinically indicated. For pulmonary metastasis, either radiograph or CT is recommended, with the latter having theoretical advantages but no proven survival benefit to date. Extrapulmonary metastases are rare in most sarcoma types, so the literature only supports extrapulmonary surveillance for certain diagnoses. This topic is complicated by the diversity of sarcomas, the limited evidence, and the indefinite, often conflicting recommendations; therefore, it is critical for providers to understand the existing research and guidelines to determine optimal surveillance strategies for their patients.

Optimization of the Therapeutic Approach to Patients with Sarcoma: Delphi Consensus

Soft tissue sarcomas (STS) constitute a heterogeneous group of rare solid tumors associated with significant morbidity and mortality. The evaluation and treatment of STS require a multidisciplinary team with extensive experience in the management of these types of tumors. National and international clinical practice guidelines for STS do not always provide answers to a great many situations that specialists have to contend with in their everyday practice. This consensus provides a series of specific recommendations based on available scientific evidence and the experience of a group of experts to assist in decision-making by all the specialists involved in the management of STS.

Local recurrence of soft-tissue sarcoma: issues in imaging surveillance strategy

Soft-tissue sarcomas pose diagnostic and therapeutic challenges to physicians, owing to the large number of subtypes, aggressive tumor biology, lack of consensus on management, and controversy surrounding interval and duration of surveillance scans. Advances in multidisciplinary management have improved the care of sarcoma patients, but controversy remains regarding strategies for surveillance following definitive local control. This review provides an updated, comprehensive overview of the current understanding of the risk of local recurrence of soft-tissue sarcoma, by examining the literature based on features such as histological type and grade, tumor size, and resection margin status, with the aim of helping clinicians, surgeons, and radiologists to develop a tailored approach to local imaging surveillance.

Preoperative Ultrasonographic Evaluation for Malignancy of Soft-Tissue Sarcoma: A Retrospective Study

Background:

Ultrasonography is useful for distinguishing between benign and malignant soft-tissue tumors. However, no study has focused on its usefulness in the differential diagnosis between low-grade and high-grade soft-tissue sarcomas. We conducted a retrospective study to determine the usefulness of the parameters of ultrasonograph and to develop a practical scoring system for distinguishing between high-grade and low-grade sarcomas.

Methods:

Twenty-two cases of low-grade and 43 cases of high-grade malignant soft-tissue sarcoma were enrolled. Ultrasonography parameters including the longest diameter, depth of the tumor, echogenicity, tumor margin, and vascularity defined according to Giovagnorio’s criteria were analyzed as factors to distinguish between the two types of sarcoma. Significant factors were entered into a multivariate model to define the scores for distinction according to the odds ratio. The usefulness of the score was analyzed via receiver operating characteristic analyses.

Results:

In univariate analysis, tumor margin, echogenicity, and vascularity were significantly different between low- and high-grade sarcomas. In the multivariate regression model, the odds ratio for high-grade vs. low-grade sarcoma was 8.8 for tumor margin, 69 for echogenicity, and 8.3 for vascularity. Scores for the risk factors were defined as follows: 1, ill-defined margin; 2, hypoechoic echogenicity; and 1, type IV in Giovagnorio’s criteria. The sum of each score was confirmed by receiver operating characteristic analysis. The area under the curve was 0.95, with a cut-off score of 3, indicating that the scoring system was useful.

Conclusion:

The ultrasonography parameters of tumor margin, echogenicity, and vascularity are useful for distinguishing between low- and high-grade sarcomas.

Does an Algorithmic Approach to Using Brachytherapy and External Beam Radiation Result in Good Function, Local Control Rates, and Low Morbidity in Patients With Extremity Soft Tissue Sarcoma?

BACKGROUND

High-dose-rate brachytherapy (HDR-BT) and external-beam radiation therapy (EBRT) are two modalities used in the treatment of soft tissue sarcoma. Previous work at our institution showed early complications and outcomes for patients treated with HDR-BT, EBRT, or a combination of both radiation therapy modalities. As the general indications for each of these approaches to radiation therapy differ, it is important to evaluate the use of each in an algorithmic way, reflecting how they are used in contemporary practice at sites that use these treatments. QUESTION/PURPOSES: (1) To determine the proportions of intermediate- and long-term complications associated with the use of brachytherapy in the treatment of primary high-grade extremity soft tissue sarcomas; (2), to characterize the long-term morbidity of the three radiation treatment groups using the Radiation Therapy Oncology Group/ European Organization for Research and Treatment of Cancer (RTOG/EORTC) Late Radiation Morbidity Scoring Scheme; (3) to determine whether treatment with HDR-BT, EBRT, and HDR-BT+EBRT therapy, in combination with limb-salvage surgery, results in acceptable local control in this high-risk group of sarcomas.

METHODS

We retrospectively studied data from 171 patients with a diagnosis of high-grade extremity soft tissue sarcoma treated with limb-sparing surgery and radiation therapy between 1990 and 2012 at our institution, with a mean followup of 72 months. Of the 171 patients, 33 (20%) were treated with HDR-BT, 128 (75%) with EBRT, and 10 (6%) with HDR-BT+EBRT. We excluded 265 patients with soft tissue sarcomas owing to axial tumor location, previous radiation to the affected extremity, incomplete patient records, patients receiving primary amputation, recurrent tumors, pediatric patients, low- and intermediate-grade tumors, and rhabdoid histology. Fifteen patients (9%) were lost to followup for any reason including died of disease or other causes during the first 12 months postoperatively. This included four patients who received HDR-BT (12%), 11 who received EBRT (9%), and none who received HDR-BT+EBRT (0%) with less than 12 months followup. Determination of radiation therapy technique for each patient was individualized in a multidisciplinary forum of sarcoma specialists. Anticipated close or positive surgical margins and a low likelihood of complex soft tissue procedures were factors that encouraged use of brachytherapy, whereas the anticipated need for secondary procedures and/or soft tissue coverage encouraged use of EBRT alone. Combination therapy was used when the treatment volume exceeded the treatment field of the brachytherapy catheters or when the catheters were used to boost a close or positive surgical margin. Local recurrence, complications, and morbidity outcomes scores (RTOG) were calculated based on chart review. Between-group comparisons pertaining to the proportion of patients experiencing complications, morbidity outcomes scores, and local recurrence rates were not performed because of dissimilarities among the patients in each group at baseline.

RESULTS

The HDR-BT treatment group showed a high incidence of intermediate-term complications, with the three most common being: deep infection (33%, 11 of 33); dehiscence and delayed wound healing (24%, eight of 33); and seroma and hematoma (21%, seven of 33). The EBRT group showed a high incidence of intermediate- and long-term complications with the three most common being: chronic radiation dermatitis (35%, 45 of 128); fibrosis (27%, 35 of 128); and chronic pain and neuritis (13%, 16 of 128). The RTOG scores for each treatment group were: HDR-BT 0.8 ± SD 1.2; EBRT 1.9 ± 2.0; and HDR-BT+EBRT 1.7 ± 1.7. Overall, 142 of 169 (84%) patients were free from local recurrence: 27 (82%) in the HDR-BT group, 108 (86%) in the EBRT group, and seven (70%) in the combination therapy group.

CONCLUSIONS

In this single-institution study, an algorithmic approach to using HDR-BT and EBRT in the treatment of patients with high-grade soft tissue sarcomas can yield acceptable complication rates, good morbidity outcome scores, and a high degree of local control. Based on these results, we believe HDR-BT is best for patients with an anticipated close margin, a positive surgical margin, and for patients who are unlikely to receive a complex soft tissue procedure. Conversely, if a secondary procedure and/or soft tissue coverage are likely to be used, EBRT alone may be reasonable. Finally, combination therapy might be considered when the treatment volume exceeded the treatment field capacity for HDR-BT or when the catheters were used to boost a close or positive surgical margin.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Use of liquid biopsies to monitor disease progression in a sarcoma patient: a case report

BACKGROUND

Many patients experience local recurrence or metastases after receiving potentially curative treatment, and early detection of these events is important for disease control. Recent technological advances make it possible to use blood plasma containing circulating cell-free tumour DNA (ctDNA) as a liquid biopsy. In this case report we show how serial liquid biopsies can be used to monitor the disease course and detect disease recurrence in a sarcoma patient.

CASE PRESENTATION

A 55-year-old male presented with a rapidly growing, painful palpable mass in the left groin region, and a biopsy revealed a high-grade malignant spindle cell sarcoma. No metastases were detected on radiologic imaging scans. Using targeted resequencing with a custom 900 cancer gene panel, eight somatic mutations among them KRAS and NF1, were identified in the primary tumour. Targeted resequencing of plasma cell-free DNA (ctDNA) collected before and after surgery and at disease progression confirmed the presence of six of eight mutations at all three time points. The ctDNA level, estimated from the somatic allele frequencies of these six mutations, was high in plasma taken at the time of surgery, at levels similar to the primary tumour. Detection of low levels of ctDNA three days after surgery indicated persistent microscopic disease. Repeated radiologic imaging six weeks postoperatively showed widespread metastatic disease in the lungs, skeleton and the pelvic region. At this time point there was a dramatic increase in the ctDNA level, reflecting the disease progression of the patient. The patient had an unusually aggressive cancer, and succumbed to the disease 13 weeks after surgery.

CONCLUSIONS

This case report demonstrated that targeted resequencing of ctDNA from longitudinal collected plasma can be used to monitor disease progression in a soft tissue sarcoma patient, including manifestation of metastatic disease. The ctDNA represented the genomic profile of the tumour, supporting clinical use of liquid biopsies to identify tumour-specific mutations as well as recurrent disease.

Extremity Soft Tissue Sarcoma: Tailoring Resection to Histologic Subtype

Soft tissue sarcomas comprise tumors originating from mesenchymal or connective tissue. Histologic grade is integral to prognosis. Because sarcoma management is multimodal, histologic subtype should inform optimum treatment. Appropriate biopsy and communication between surgeon and pathologist can help ensure a correct diagnosis. Treatment often involves surgical excision with wide margins and adjuvant radiotherapy. There is no consensus on what constitutes an adequate margin for histologic subtypes. An appreciation of how histology corresponds with tumor biology and surgical anatomic constraints is needed for management of this disease. Even with the surgical goal of wide resection being obtained, many patients do not outlive their disease.

The width of resection margins influences local recurrence in soft tissue sarcoma patients

BACKGROUND

Patients with soft tissue sarcoma (STS) being treated following the standardized guidelines can still not be guaranteed to remain free from local recurrence (LR). A complete tumour resection has been accepted as a major prognostic factor for LR. This retrospective study was designed to analyse the influence of two different classifications of resection margins (R-classification and UICC-classification) on LR in STS patients.

MATERIALS AND METHODS

Of 411 patients treated at our institution for STS, 265 were eligible for statistical analysis. Kaplan-Meier curves and Cox regression models were used to assess the impact of an R0 resection according to the R-classification (resection margin clear but allowing <1 mm) and according to the UICC-classification (minimal resection margin ≥1 mm) on LR.

RESULTS

Survival curves showed a lower LR rate for R0 resections in the UICC-classification, namely 1.3%, 12% and 12% as compared to 2.1%, 9.5% and 16.5% for the R-classification. In multivariate analysis calculated separately for each classification, R1 resection as defined by the R-classification (HR: 11.214; 95%CI: 2.394-52.517; p = 0.002) as well as by UICC-classification (HR: 15.634; 95%CI: 2.493-98.029; p = 0.003) remained significant.

CONCLUSION

In our study, margin status according to both classifications represents an independent prognostic factor for LR in patients with STS following curative surgery. Local control rates were superior after a minimal resection margin of 1 mm (R0 by UICC-classification) compared to R0 resections after the R-classification.

How long should we follow patients with soft tissue sarcomas?

BACKGROUND

Guidelines suggest that followup for low-grade soft tissue sarcomas should be every 3 to 6 months for 2 to 3 years and then annually, and for high-grade sarcomas every 3 to 6 months for 2 to 5 years, then every 6 months for the next 2 years, and then annually. However, there is only very limited evidence to support these strategies.

QUESTIONS/PURPOSES

In a population of patients treated surgically for soft tissue sarcomas, we evaluated the (1) timing of diagnosis of local recurrences after sarcoma excision; (2) timing of diagnosis of distant metastases; and (3) the difference in those parameters based on tumor size and grade.

METHODS

Patients diagnosed with soft tissue sarcomas and who underwent surgical excision between 1978 and 2008 were retrospectively reviewed. Age, histologic diagnosis, Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade, tumor location, and size were reviewed at a mean of 6 years (range, 1 month to 30 years). We met with patients every 3 months for 5 years, every 6 months for 10 years, and then annually until 15 years after surgery. Eight hundred sixty-seven patients with a median age at diagnosis of 52 years were eligible for analysis. The incidence of local recurrence and metastases was calculated for every 2-year period and presented per 1000 person-years.

RESULTS

Ninety-eight patients (11%) developed local recurrence at a median time of 19 months; 90% of patients who had local recurrences had them within 7.1 years, and 95% occurred by 8.6 years. One hundred ninety-eight patients (23%) developed distant metastases at a median time of 12 months; 90% of patients who developed metastases developed them by 4.2 years and 95% did so by 7.3 years. High-grade tumors had a higher incidence of local recurrence and metastases in first 2 years, whereas low-grade tumors recurred at a constant rate throughout the followup period.

CONCLUSIONS

Followup beyond 10 years does not yield a sufficient number of local recurrences or metastases to warrant further monitoring.

LEVEL OF EVIDENCE

Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.