What is an adequate margin for infiltrative soft-tissue sarcomas?

Surgical Margins in Musculoskeletal Sarcoma

» Negative margin resection of musculoskeletal sarcomas is associated with reduced risk of local recurrence.» There is limited evidence to support an absolute margin width of soft tissue or bone that correlates with reduced risk of local recurrence.» Factors intrinsic to the tumor, including histologic subtype, grade, growth pattern and neurovascular involvement impact margin status and local recurrence, and should be considered when evaluating a patient's individual risk after positive margins.» Appropriate use of adjuvant therapy, critical analysis of preoperative advanced cross-sectional imaging, and the involvement of a multidisciplinary team are essential to obtain negative margins when resecting sarcomas.

The prognostic significance of surgical resection margins for local recurrence, distant metastasis, and overall survival in sarcoma

BACKGROUND AND OBJECTIVES

Surgical resection with microscopically negative margins constitutes one of the key elements of a curative therapeutic approach for localized sarcomas. However, the prognostic value of quantitative margin width remains controversial. We sought to determine the prognostic significance of margin status and margin width for local recurrence (LR), distant recurrence (DR), and overall survival.

METHODS

Retrospective analysis of 210 patients undergoing resection of localized sarcoma between 1997 and 2018 at a national sarcoma reference center.

RESULTS

Logistic regression did not reveal an effect of metric margin width as a prognostic factor for LR (odds ratio [OR] = 0.98, p = 0.574), DR (OR = 1, p = 0.908), or overall survival (hazard ratio = 0.98, 95% confidence interval = 0.73-1.20, p = 0.609). Subgroup analysis revealed no differences between complete first resections (R0) and re-resections (re-R0) following unplanned R1-resections for LR (p = 0.727) and overall survival (p = 0.125), but a significantly higher DR-rate in re-R0 cases (p = 0.022).

CONCLUSIONS

Achieving a negative margin is essential in sarcoma surgery, however, metric margin width was not associated with disease-specific outcomes. Re-resection of unplanned R1-resections should be performed to control for LR and overall survival rates. As re-R0 cases were at significantly higher risk of DR, these patients should be followed up closely in standardized surveillance protocols.

Biology and Management of High-Grade Myxofibrosarcoma: State of the Art and Future Perspectives

Myxofibrosarcoma (MFS) is one of the most common adult soft tissue sarcomas, typically arising in the extremities. Histologically, MFS is classified into three grades: low, intermediate, and high. Histological grades correlate with distant metastases and tumor-associated mortality. The diagnosis of MFS is challenging due to a lack of well-characterized immunohistochemical markers. High-grade MFS displays highly complex karyotypes with multiple copy number alterations. Recent integrated genomic studies have shown the predominance of somatic copy number aberrations. However, the molecular pathogenesis of high-grade MFS remains poorly understood. The standard treatment for localized MFS is surgical resection. The systemic treatment options for advanced disease are limited. This review provides an updated overview of the clinical and imaging features, pathogenesis, histopathology, and treatment of high-grade MFS.

Cathepsin protease expression in infiltrative soft tissue sarcomas: cathepsin-K correlates with infiltrative tumor growth and clinical outcomes

Cathepsin proteases, activated in the lysosomes, are upregulated in many cancers. Intraoperative detection systems of microscopic residual tumor using cathepsin-mediated release of fluorescent nanoparticles may guide surgical excisions to improve local control. We sought to define the genetic and proteomic expression of cathepsins and their clinicopathological correlates in myxofibrosarcoma and undifferentiated pleomorphic sarcoma (UPS)-soft tissue sarcomas with high rates of positive resection margins and local recurrence-and to establish a cellular justification for cathepsin-dependent systems to identify residual cancer in the resection bed. Real-time quantitative polymerase chain reaction analysis of 58 fresh-frozen tumor specimens revealed that 56 (97%) had elevated mRNA expression of ≥1 cathepsin, including cathepsin-B (79%), cathepsin-K (59%), cathepsin-L (71%), and -S (71%). Immunohistochemical analysis of these fresh-frozen specimens revealed that 98% of tumors were positive for one or more of cathepsin-B (85%), cathepsin-K (50%), cathepsin-L (63%), and -S (10%). Strong cathepsin-K expression was associated with greater risks of local recurrence (hazard ratio, 3.78; p = 0.044) and disease-specific mortality (hazard ratio, 3.70; p = 0.025). Immunohistochemical analysis of 33 formalin-fixed paraffin-embedded block samples revealed that 97% were positive for cathepsin-B (88%), cathepsin-K (76%), cathepsin-L (52%), or -S (52%) at the tumor periphery; cathepsin-K positivity correlated with a radiographic tail-like sign (p = 0.004) and microscopic infiltrative growth (p = 0.020). We conclude that cathepsins are broadly overexpressed in myxofibrosarcoma and UPS, and cathepsin-K may be an immunohistochemical marker of local infiltration and poorer prognosis that could be used to guide precision surgery.

Local relapse of soft tissue sarcoma of the extremities or trunk wall operated on with wide margins without radiation therapy

BACKGROUND

The quality of surgical margins is the most important factor affecting local control in soft tissue sarcoma (STS). Despite this, there is no universally accepted consensus on the definition of an adequate surgical margin or on which patients should be offered radiation therapy. This study focuses on local control and its prognostic factors in patients with trunk wall and extremity STS.

METHODS

Adult patients with a final diagnosis of trunk wall or extremity STS referred to a single tertiary referral centre between August 1987 and December 2016 were identified from a prospective institutional database. Patients were treated according to a protocol instituted in 1987. The classification of surgical margins and indications for radiation therapy were based on anatomy and strict definition of surgical margins as metric distance to the resection border. Local treatment was defined as adequate if patients received either surgery with wide margins alone or marginal surgery combined with radiation therapy. Margins were considered wide if the tumour was excised with pathological margins greater than 2.5 cm or with an uninvolved natural anatomical barrier. After treatment, patients were followed up with local imaging and chest X-ray: 5 years for high-grade STS, 10 years for low-grade STS.

RESULTS

A total of 812 patients were included with a median follow-up of 5.8 (range 0.5-19.5) years. Forty-four patients had a grade 1 tumour: there were no instances of recurrence in this group thus they were excluded from further analysis. Five-year local control in the 768 patients with grade 2-3 STS was 90.1 per cent in patients receiving adequate local treatment according to the protocol. Altogether, 333 patients (43.4 per cent) were treated with wide surgery alone and their 5-year local control rate was 91.1 per cent. Among patients treated with wide surgery alone, deep location was the only factor adversely associated with local relapse risk in multivariable analysis; 5-year local control was 95.3 per cent in superficial and 88.3 per cent in deep-sited sarcomas (hazards ratio 3.154 (95% c.i. 1.265 to 7.860), P = 0.014).

CONCLUSION

A high local control rate is achievable with surgery alone for a substantial proportion of patients with STS of the extremities or superficial trunk wall.

Oncologic outcomes in myxofibrosarcomas: the role of a multidisciplinary approach and surgical resection margins

BACKGROUNDS

Myxofibrosarcomas (MFS) are malignant soft tissue sarcomas with an infiltrative growth pattern and propensity for local recurrence(LR).We aimed to assess our management of MFS and make recommendations about the role of a multidisciplinary team approach and margin widths.

METHODS

Fifty-seven patients were identified with MFS treated at a single sarcoma centre between 1998 and 2020. Patients were stratified based on whether they presented for a planned resection (59.6%) or after an unplanned resection (40.4%) performed at a non-specialized facility. All patients underwent radiotherapy before definitive surgery.

RESULTS

73.7% underwent a combined onco-plastic approach. The 5 year LRFS rate was 78.2% (84.4%, planned, versus 70.1%, unplanned, P = 0.194) and found comparable oncological outcomes between the planned and unplanned groups for the 5 year metastasis free survival (74.5% versus 86.1%, P = 0.257), disease free survival (70.1% versus 72.4%, P = 0.677), and Overall Survival (64.5% versus 75.9%, P = 0.950). Margin width ≥ 2 cm was obtained in 84.2% of cases and improved local control (HR = 0.22; 95% CI 0.06-0.81; P = 0.023), metastasis (HR = 0.24; 95% CI 0.07-0.80; P = 0.019) and mortality rates (HR = 0.23; 95% CI 0.09, 0.61; P = 0.003) compared to <2 cm. Margin width > 3 cm did not further affect oncological outcomes.

CONCLUSION

Our study shows that a multidisciplinary team approach allows the achievement of low local recurrence rate and good oncological outcomes of myxofibrosarcomas, regardless of presentation status. We recommend a minimum of 2 cm margin width.

Haemorrhagic soft-tissue sarcoma: Oncological outcomes and prognostic factors for survival

INTRODUCTION

Haemorrhagic soft-tissue sarcomas (HSTS) are characterised by aggressive local growth and highly metastatic behaviour. We aimed to describe oncological outcomes and prognostic factors.

MATERIALS AND METHODS

Retrospective review including 64 patients treated with palliation (n = 7), with limb salvage surgery (LSS) (n = 9), with neoadjuvant radiotherapy (RT) + LSS (n = 12), with LSS + adjuvant RT (n = 30) or amputation (n = 6). Kaplan-Meier survival analysis estimated overall survival (OS), metastasis-free survival (MFS) and local recurrence-free survival (LRFS). After uni- and multivariate analysis, prognostic factors affecting OS, MFS and LRFS were identified.

RESULTS

Median age was 67 years (IQR 23 years) with median follow-up of 11 months (IQR 28 months). All cases were high grade. Eight (13%) had pulmonary metastases at presentation and another 40 (63%) developed metastases after median 9 months (IQR 19 months). Median OS was 12 months (IQR 38 months), and estimated OS after two-years was 15.9% and 52.9% for patients with and without metastatic disease at presentation, respectively. Improved OS was associated with negative resection margins (p = 0.031), RT (p = 0.045), neoadjuvant RT (versus adjuvant RT, p = 0.044) and amputation (versus LSS, p < 0.001). MFS was 35.1% after two-years. LR occurred in 18 of 51 (35.3%) patients with surgically treated localised disease. LRFS was 63.4% after two-years and significantly affected by a negative margin (p = 0.042) and RT (p = 0.001).

CONCLUSION

Haemorrhagic soft-tissue sarcomas should be excised, either with amputation or LSS with a clear resection margin. If LSS is attempted, neoadjuvant RT reduces the risk of tumour spillage and early LR, enhances the feasibility of achieving clear resection margins, and offers superior overall survival compared to adjuvant RT.

Current research and management of undifferentiated pleomorphic sarcoma/myofibrosarcoma

Undifferentiated pleomorphic sarcoma (UPS), once termed as malignant fibrous histiocytoma, has always been diagnosed exclusively in clinical practice because it lacks any defined resemblance to normal mesenchymal tissue. Although myxofibrosarcoma (MFS) has been separated from UPS due to its fibroblastic differentiation with myxoid stroma, UPS and MFS are still identified as a sarcoma group in terms of molecular landscapes. In this review article, we will describe the associated genes and signaling pathways involved in the process of sarcoma genesis and make a summary of conventional management, targeted therapy, immunotherapy, and some novel potential treatments of UPS/MFS. With the progressive advancements in medical technology and a better understanding about the pathogenic mechanism of UPS/MFS in the coming decades, new lights will be shed on the successful management of UPS/MFS.

Clinical Outcomes of Soft Tissue Sarcoma around the Elbow Joint: A Retrospective Single Institution Study

Background

We report a retrospective case series analysis of clinical outcomes of patients with soft tissue sarcoma around the elbow.

Methods

Twenty-two patients underwent surgical tumor excision between January 1999 and May 2017, with a mean follow-up of 85.2 months.

Results

Six tumors were localized in the upper arm, nine in the elbow, and seven in the forearm. Sixteen tumors were deep-seated, and six were superficially located. Fifteen patients underwent wide excision, including one amputation, and 18 achieved (81.8%) negative margins histologically. Two local recurrences and four distant metastases developed. The mean Musculoskeletal Tumor Society score was 92.0% (range, 33.3-100). The 5-year local recurrence-free survival rate, metastasis-free survival rate, and overall survival rate were 90.0%, 77.0%, and 79.7%, respectively.

Conclusions

Local control and limb function can have favorable outcomes when the tumor excised has a histologically negative margin without sacrificing the major structure.

Undifferentiated Pleomorphic Sarcoma of the Duodenal Papilla: A Rare Case and Worth Discussing History

Background

Undifferentiated pleomorphic sarcoma (UPS) is a malignant tumor that originates in the mesenchymal tissue and is common in the extremities and retroperitoneum. Primary UPS of the duodenal papilla is rare and a distinct clinical entity.

Case presentation

In this report, a 48-year-old Chinese man was admitted to our hospital with symptoms of melena. The patient underwent choledochectomy and choledochaljejunostomy for obstructive jaundice 8 years before admission. Endoscopic examination after admission confirmed a mass located at the duodenal papilla. Then, the duodenal papilla and tumor resection were performed, and the histopathology report confirmed the diagnosis of UPS. The patient refused further treatment and died 2 months later due to local recurrence and intrahepatic metastasis.

Conclusions

It is rare that the mass in the duodenal papilla is diagnosed as UPS. The unpredicted behavior of these tumors warrants a careful plan considering their indolent nature and possible recurrence and metastasis. The prognosis was poor despite the early complete resection.

Local hyperthermia combined with chemotherapy for the treatment of multiple recurrences of undifferentiated pleomorphic sarcoma: A case report

BACKGROUND

Undifferentiated pleomorphic sarcoma (UPS) is a type of soft tissue sarcoma, the histologic origin and differentiation direction of which are still unclear. There are few treatment options for UPS other than surgery. Herein we describe a patient who had multiple recurrences of UPS postoperatively, but R0 resection was achieved by local hyperthermia combined with chemotherapy, thus providing a new treatment approach for similar situations.

CASE SUMMARY

A 65-year-old man sought evaluation from a physician for a mass on his right back. After surgery, the pathologic diagnosis was fibrosarcoma. During the follow-up evaluations until 2021, the patient had four relapses of varying degrees. Postoperative pathology confirmed the recurrence of UPS on the right back. In March 2021, he underwent local hyperthermia combined with two cycles of chemotherapy for recurring lesions. After magnetic resonance imaging re-examination and preoperative examination, the patient chose surgery again. During the operation, the tumors were easy to excise, the amount of bleeding decreased significantly, and the pathologic evaluation confirmed that one of the specimens was an R0 excision.

CONCLUSION

Local hyperthermia combined with chemotherapy enables R0 resection to be achieved in patients with advanced UPS recurrence.

Local hyperthermia combined with chemotherapy for the treatment of multiple recurrences of undifferentiated pleomorphic sarcoma: A case report

BACKGROUND

Undifferentiated pleomorphic sarcoma (UPS) is a type of soft tissue sarcoma, the histologic origin and differentiation direction of which are still unclear. There are few treatment options for UPS other than surgery. Herein we describe a patient who had multiple recurrences of UPS postoperatively, but R0 resection was achieved by local hyperthermia combined with chemotherapy, thus providing a new treatment approach for similar situations.

CASE SUMMARY

A 65-year-old man sought evaluation from a physician for a mass on his right back. After surgery, the pathologic diagnosis was fibrosarcoma. During the follow-up evaluations until 2021, the patient had four relapses of varying degrees. Postoperative pathology confirmed the recurrence of UPS on the right back. In March 2021, he underwent local hyperthermia combined with two cycles of chemotherapy for recurring lesions. After magnetic resonance imaging re-examination and preoperative examination, the patient chose surgery again. During the operation, the tumors were easy to excise, the amount of bleeding decreased significantly, and the pathologic evaluation confirmed that one of the specimens was an R0 excision.

CONCLUSION

Local hyperthermia combined with chemotherapy enables R0 resection to be achieved in patients with advanced UPS recurrence.

The Role of MRI-Guided Radiotherapy for Soft Tissue Sarcomas

Soft tissue sarcomas (STS) are a rare class of tumors that originate from mesenchymal tissues and occur most frequently in the extremities, trunk, and retroperitoneum. Surgical resection with R0 margins is the primary curative treatment for most localized STS. In this setting, radiation therapy is used either pre-operatively or post-operatively to reduce the rate of local recurrence. Modern pre- or post-operative radiation therapy rely on the use of MRI sequences to guide target delineation during treatment planning. MRI-guided radiotherapy also offers unique advantages over CT-guided approaches in differentiating STS from surrounding normal soft tissues and enabling better identification of target volumes on daily imaging. For patients with unresectable STS, radiation therapy may offer the best chance for local tumor control. However, most STS are relatively radioresistant with modest rates of local control achieved using conventionally fractionated radiation. Specialized techniques such as hypofractionated radiation may allow for dose intensification and may increase rates of local control for STS. In these settings, MRI becomes even more critical for the delineation of targets and organs at risk and management of tumor and organ at risk motion during and between radiotherapy treatment fractions.

Intraoperative Near-Infrared Fluorescence Guided Surgery Using Indocyanine Green (ICG) for the Resection of Sarcomas May Reduce the Positive Margin Rate: An Extended Case Series

BACKGROUND

Sarcomas are rare, aggressive cancers which can occur in any region of the body. Surgery is usually the cornerstone of curative treatment, with negative surgical margins associated with decreased local recurrence and improved overall survival. Indocyanine green (ICG) is a fluorescent dye which accumulates in sarcoma tissue and can be imaged intraoperatively using handheld near-infrared (NIR) cameras, theoretically helping guide the surgeon's resection margins.

METHODS

Patients operated on between 20 February 2019 and 20 October 2021 for intermediate to high grade sarcomas at our centres received either conventional surgery, or were administered ICG pre-operatively followed by intra-operative NIR fluorescence guidance during the procedure. Differences between the unexpected positive margin rates were compared.

RESULTS

115 suitable patients were identified, of which 39 received ICG + NIR fluorescence guided surgery, and 76 received conventional surgery. Of the patients given ICG, 37/39 tumours fluoresced, and surgeons felt the procedure was guided by the intra-operative images in 11 cases. Patients receiving ICG had a lower unexpected positive margin rate (5.1% vs. 25.0%, p = 0.01).

CONCLUSIONS

The use of NIR fluorescence cameras in combination with ICG may reduce the unexpected positive margin rate for high grade sarcomas. A prospective, multi-centre randomised control trial is now needed to validate these results.

MRI Features as Prognostic Factors in Myxofibrosarcoma: Proposal of MRI Grading System

RATIONALE AND OBJECTIVES

Myxofibrosarcoma (MFS) is a common soft tissue sarcoma in the elderly patients with both clinical and magnetic resonance imaging (MRI) peculiar features: very high recurrence rate, relatively low risk of distant metastases. On MRI it shows an infiltrative pattern ("tail sign") and high myxoid matrix content with water-like appearance on fluid-sensitive sequences. Due to these unusual characteristics, we propose a specific MRI grading system to stratify the risk of local recurrence (LR) and offer other prognostic information.

MATERIALS AND METHODS

Two expert radiologists retrospectively and blindly reviewed preoperative MRI of 150 patients affected by MFS of the extremities treated at a single Institution. Myxoid matrix component and contrast enhancement of the tumor were evaluated and graded with a semiquantitative method. The presence of an infiltrative pattern, the depth of the tumor (deep and/or superficial) and tumor sizes were also recorded. MRI features were analyzed separately and correlated to LR risk, sarcoma specific survival and distant metastases rate. Then, according to the statistical significance of the correlation between MRI features and prognosis a 3-grade scoring system was proposed and evaluated to assess the risk of LR.

RESULTS

Mean age was 66.1 ± 14.4 years; mean follow-up was 16 ± 28.3 months. The MRI features most associated with higher risk of LR resulted to be: lesion sizes (both volume and maximum diameter with a cut-off of 20 cm - p = 0.01), the "tail sign" (p = 0.045), and high myxoid matrix content with MRI water-like appearance (p = 0.0493). Ninety-four patients (94 of 150- 62.7%) were grade 1, 33 (22.0%) grade 2, and 23 (15.3%) grade 3. Interobserver agreement was substantial with K= 0.779 (95%CI 0.685-0.874). Higher grades of MRI grading system proposed were significantly associated with an increased LR risk, hazard ratio = 2.031 (95%CI 1.366-3.019; p < 0.001).

CONCLUSION

This is the largest series evaluating MRI features as prognostic factors for MFS. The MRI grading system proposed is significantly able to stratify the risk of LR in MFS of the extremities. The system is applicable to all the standard MRI studies protocols, might help in surgical planning, and may offer prognostic information.

Surgical excision margins for fibrohistiocytic tumors, including atypical fibroxanthoma and undifferentiated pleomorphic sarcoma: A probability model based on a systematic review

BACKGROUND

Mohs micrographic surgery or wide local excision is the treatment of choice for fibrohistiocytic tumors with metastatic potential, including atypical fibroxanthoma (AFX) and cutaneous undifferentiated pleomorphic sarcoma (cUPS). Since margin clearance is the strongest predictor of clinical recurrence, improved recommendations for appropriate surgical margins help delineate uniform excision margins when intraoperative margin assessment is not available.

OBJECTIVE

To determine appropriate surgical wide local excision margins for AFX and cUPS.

METHODS

Literature search (Ovid MEDLINE, Embase, Web of Science, and Cochrane Library from inception to March 2020) to detect case-level data. Estimation of margins required using a mathematical model based on extracted cases without recurrences.

RESULTS

Probabilistic modeling based on 100 cases extracted from 37 studies showed peripheral clearance margin (ie, wide local excision margin) calculated to clear 95% of all tumors was 2 cm for AFX and 3 cm for cUPS. AFX tumors 1 cm or less required a margin of 1 cm.

LIMITATIONS

Data were extracted from published cases.

CONCLUSIONS

Atypical fibroxanthoma removed with at least a 2-cm peripheral excision margin is less likely to recur. Smaller tumors 1 cm or less can be treated with a more conservative margin. Margin-control surgical techniques are recommended to ensure complete removal while minimizing surgical morbidity.

Surgical Margins in Canine Cutaneous Soft-Tissue Sarcomas: A Dichotomous Classification System Does Not Accurately Predict the Risk of Local Recurrence

Simple Summary

Histological evaluation of surgical margins is crucial for correct prognostication and adjuvant treatment recommendation after excision of soft tissue sarcoma (STS) in dogs. Incompletely excised STS have a high risk of local recurrence (LR), while completely excised STS without other negative prognostic factors are generally associated with a good prognosis. However, guidelines are lacking on how to manage STS excised with clean but close margins (CbCM), although some authors advocated their inclusion in the tumor-free margin group. This retrospective study investigates the impact of CbCM on LR of canine STS. Ninety-eight surgical excised canine STS at first presentation were included. Cumulative incidence of LR was estimated for each category of margins (tumor-free, infiltrated, CbCM), and after grouping CbCM alternatively in the tumor-free and infiltrated category. Cumulative incidence of LR at three years differed significantly between the three categories, and it was estimated to be 42% with infiltrated margins, 23% with CbCM, 7% with tumor-free margins. Both when CbCM were grouped with infiltrated margins or with tumor-free margins, the incidence of LR was statistically different. The rate of LR with CbCm was greater than with tumor-free margins. The category CbCM may be considered as a separate prognostic category.

Abstract

Adjuvant treatments are recommended in dogs with incompletely excised cutaneous soft-tissue sarcoma (STS) to reduce the risk of local recurrence (LR), although guidelines are lacking on how to manage clean but close margins (CbCM). This retrospective study investigates the impact of CbCM on LR of canine STS. Ninety-eight surgically excised canine STS at first presentation were included. Tissue samples were routinely trimmed and analyzed. Cumulative incidence of LR was estimated for each category of margins (tumor-free, infiltrated, CbCM), and included CbCM in the tumor-free and infiltrated category, respectively. The prognostic impact on LR was then adjusted for relevant prognostic factors. Cumulative incidence of LR at three years differed significantly between the three categories (p = 0.016), and was estimated to be 42% with infiltrated margins, 23% with CbCM, 7% with tumor-free margins. Both when CbCM were grouped with infiltrated margins (p = 0.033; HR = 5.05), and when CbCM were grouped with tumor-free margins (p = 0.011; HR = 3.13), a significant difference between groups was found. STS excised with infiltrated margins had the greatest risk of LR. The rate of LR with CbCm was greater than recurrence rate of tumor-free margins. The category CbCM may be considered as a separate prognostic category.

Late Local Recurrence and Metastasis in Soft Tissue Sarcoma of the Extremities and Trunk Wall: Better Outcome After Treatment of Late Events Compared with Early

Background

Approximately 80% of soft tissue sarcoma (STS) recurrences, local and metastatic disease, are diagnosed within the first 3 years after primary diagnosis and treatment. Recurrences, however, can present after a longer period of remission. Our goal was to identify factors that may predict the risk of late recurrence.

Methods

We identified 677 patients with STS of the extremities and trunk wall from a population-based sarcoma register. Of these, 377 patients were alive and event-free at 3 years and were included for analysis of possible risk factors for late recurrence.

Results

Fifty-five of 377 (15%) patients developed late recurrence: 23 local recurrence, 21 metastasis, and 11 both manifestations. With R0 wide surgical margin as reference, R0 marginal (hazard ratio [HR] 2.6; p = 0.02) and R1 (HR 5.0; p = 0.005) margins were risk factors for late local recurrence. Malignancy grade (HR 8.3; p = 0.04) and R0 marginal surgical margin (HR 2.3; p = 0.04) were risk factors for late metastasis. We could not find a statistically significant correlation of late recurrence with many of the generally known risk factors for local recurrence and metastasis in STS. Outcome after treatment of late recurrences was better compared with outcome after treatment of early events.

Conclusions

Late recurrences, albeit relatively rare, do occur. Outcome after treatment was good compared with outcome after early events. Long surveillance of all patients with high-grade STS, especially if R0 wide surgical margin is not achieved in the primary treatment, appear to be well justified.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-09942-8.

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.

Myxofibrosarcoma: Clinical and Prognostic Value of MRI Features

Myxofibrosarcoma is one of the most common soft tissue sarcomas in the elderly. It is characterized by an extremely high rate of local recurrence, higher than other soft tissue tumors, and a relatively low risk of distant metastases.Magnetic resonance imaging (MRI) is the imaging modality of choice for the assessment of myxofibrosarcoma, which plays a key role in the preoperative setting of these patients. MRI features associated with the high risk of local recurrence are: high myxoid matrix content (water-like appearance of the lesions), high grade of contrast enhancement and presence of an infiltrative pattern ("tail sign"). On the other hand, MRI features associated with worse sarcoma specific survival are: large size of the lesion, deep location, high grade of contrast enhancement. Recognizing the above-mentioned imaging features of myxofibrosarcoma may be helpful in stratifying the risk for local recurrence and disease-specific survival. Moreover, the surgical planning should be adjusted according to the MRI features.

Soft-tissue reconstruction after soft-tissue sarcoma resection: the clinical outcomes of 24 patients

PURPOSE

Pedicle or free-flap reconstruction is important in surgical sarcoma management. Free flaps are indicated only when pedicle flaps are considered inadequate; however, they are associated with a higher risk of flap failure, longer surgical times, and technical difficulty. To determine the skin defect size that can be covered by a pedicle flap, we investigated the clinical outcomes and complications of reconstruction using pedicle flaps vs. free flaps after sarcoma resection.

METHODS

We retrospectively studied the medical records of 24 patients with soft-tissue sarcomas who underwent reconstruction using a pedicle (n = 20) or free flap (n = 4) following wide tumour resection.

RESULTS

All skin defects of the knee, lower leg, and ankle were reconstructed using a pedicle flap. Skin defects of the knee, lower leg, and ankle were covered by up to 525 cm², 325 cm², and 234 cm², respectively. The amount of blood loss was significantly greater in the free-flap group than in the pedicle flap group (p = 0.011). Surgical time was significantly shorter in the pedicle flap group than in the free-flap group (p = 0.006). Total necrosis was observed in one (25%) patient in the free-flap group; no case of total necrosis was observed in the pedicle flap group.

CONCLUSION

Less blood loss, shorter surgical time, and lower risk of total flap necrosis are notable advantages of pedicle flaps over free flaps. Most skin defects, even large ones, of the lower extremities following sarcoma resection can be covered using a single pedicle flap or multiple pedicle flaps.

Development and validation of a prognostic nomogram for predicting the overall survival of myxofibrosarcoma patients: a large population-based study

Background

Although some studies have explored prognostic factors of myxofibrosarcoma (MFS), the sample sizes were small, generally fewer than 100 patients. There is still no effective prognostic model for MFS patients based on a large population and comprehensive factors. The present study was designed to establish and validate a large population-based, clinically relevant prognostic nomogram for predicting 3- and 5-year overall survival (OS) in patients with MFS.

Methods

We identified patients with MFS (ICD-O-3 code: 8811/3) who were diagnosed between 2004 and 2015 from the Surveillance, Epidemiology, and End Results database and separated them into training and validation cohorts (7:3 ratio). Survival was described using the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were used to identify prognostic factors of survival. An individual nomogram was established to predict OS at 3 and 5 years in MFS patients. The discriminative ability and predictive accuracy of the nomogram were compared to those of the traditional American Joint Committee on Cancer (AJCC) staging system in the training and validation cohorts. Finally, MFS patients were divided into two subgroups based on the prognostic index (PI) score of the nomogram, and the survival outcomes of the subgroups were compared.

Results

A total of 1,270 patients were included. Age at diagnosis, total number of in situ or malignant tumors, tumor size, tumor site, tumor extension, AJCC stage, surgical status, chemotherapy, and radiotherapy were the independent predictors of survival and were included in the nomogram. The nomogram had C-indexes of 0.806 in the training cohort and 0.783 in the validation cohort, which were greater than those of the sixth edition of the AJCC staging system (training cohort, 0.669 and validation cohort, 0.674). Decision curve analysis (DCA) revealed that the nomogram was useful with high clinical net benefits. Survival outcomes were significantly different between the different risk subgroups (P<0.001).

Conclusions

A novel nomogram based on a large population was constructed to evaluate survival outcomes for MFS. Its predictive efficacy was markedly superior than that of the traditional sixth edition of the AJCC staging system.

Treatment Concepts and Challenges in Nonrhabdomyosarcoma Soft Tissue Sarcomas

Pediatric nonrhabdomyosarcoma soft tissue sarcomas (NRSTSs) encompass a heterogeneous group of mesenchymal tumors with more than 50 histologic variants. The incidence of NRSTS is greater than rhabdomyosarcoma; however, each histologic type is rare. The treatment schema for all NRSTSs is largely surgical. The treatment is a risk-adapted approach based on tumor size, localization, tumor grade, and presence of metastases. Low-grade tumors are mainly managed by surgery alone, whereas for high-grade tumors a multimodal treatment concept is necessary. The multimodal treatment consists of tumor biopsy, chemotherapy, local treatment (surgery ± radiotherapy), and immunotherapy in selected conditions.

Time to Local Recurrence as a Predictor of Survival in Patients With Soft Tissue Sarcoma of the Extremity and Abdominothoracic Wall

Objective

The purpose of this retrospective study was to identify the prognostic significance of time to local recurrence (TLR) with regard to overall survival (OS) and survival after local recurrence (SAR) in patients with soft tissue sarcoma (STS) of the extremity and abdominothoracic wall.

Methods

We identified 477 patients who underwent R0 resection for localized STS of the extremity and abdominothoracic wall, from January 1995 to December 2016, of whom 190 patients developed local recurrence as their first recurrent event. Based on TLR, patients were divided into two groups: early local recurrence (ELR, <12 months) and late local recurrence (LLR, ≥12 months). The Kaplan–Meier method and Cox regression analysis were used to estimate the OS and SAR, and to identify factors associated with patient outcomes.

Results

The median follow-up time for the entire cohort was 118.4 months, and was 118.5 months for the 190 patients who developed local recurrence. Deep tumor location (HR 1.73, 95% CI 1.27–2.37, P = 0.001) and tumor grade ≥2 (G2 vs. G1: HR 1.75, 95% CI 1.21–2.53, G3 vs. G1: HR 2.57, 95% CI 1.66–3.98, P < 0.001) were associated with a higher rate of local recurrence. There were 99 patients in the ELR group and 91 in the LLR group, with a median TLR of 10.8 months for the entire cohort. Patients from the ELR group had a shorter OS and a lower 5-year OS rate than the LLR group. Univariate and multivariate analyses demonstrated TLR as an independent prognostic factor for SAR and OS, in addition to tumor grade. Also, surgical treatment and absence of metastasis after local recurrence were associated with longer SAR.

Conclusions

In patients with STS of the extremity and abdominothoracic wall, ELR after R0 resection indicated a worse prognosis than those with LLR, and TLR can be considered an independent prognostic factor for OS and SAR. Furthermore, local recurrence was significantly influenced by the depth and the histopathological grading of the primary tumor, and reoperation after local recurrence could improve survival, which means salvage surgery may still be the preferred treatment when there are surgical indications after recurrence.

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.

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.

Individualizing Follow-Up Strategies in High-Grade Soft Tissue Sarcoma with Flexible Parametric Competing Risk Regression Models

Currently, patients with extremity soft tissue sarcoma (eSTS) who have undergone curative resection are followed up by a heuristic approach, not covering individual patient risks. The aim of this study was to develop two flexible parametric competing risk regression models (FPCRRMs) for local recurrence (LR) and distant metastasis (DM), aiming at providing guidance on how to individually follow-up patients. Three thousand sixteen patients (1931 test, 1085 validation cohort) with high-grade eSTS were included in this retrospective, multicenter study. Histology (9 categories), grading (time-varying covariate), gender, age, tumor size, margins, (neo)adjuvant radiotherapy (RTX), and neoadjuvant chemotherapy (CTX) were used in the FPCRRMs and performance tested with Harrell-C-index. Median follow-up was 50 months (interquartile range: 23.3–95 months). Two hundred forty-two (12.5%) and 603 (31.2%) of test cohort patients developed LR and DM. Factors significantly associated with LR were gender, size, histology, neo- and adjuvant RTX, and margins. Parameters associated with DM were margins, grading, gender, size, histology, and neoadjuvant RTX. C-statistics was computed for internal (C-index for LR: 0.705, for DM: 0.723) and external cohort (C-index for LR: 0.683, for DM: 0.772). Depending on clinical, pathological, and patient-related parameters, LR- and DM-risks vary. With the present model, implemented in the updated Personalised Sarcoma Care (PERSARC)-app, more individualized prediction of LR/DM-risks is made possible.