Recurrence patterns and survival for patients with intermediate- and high-grade myxofibrosarcoma

The Use of Positron-Emission Tomography-Magnetic Resonance Imaging to Improve the Local Staging of Disease in Myxofibrosarcoma: A Feasibility Study

Background/Objectives: Myxofibrosarcomas (MFSs) are aggressive soft-tissue sarcomas (STSs) that often arise in the upper and lower limbs. MFSs are a highly infiltrative sarcoma subtype with a high positive margin rate and poor clinical outcomes. Their management involves multidisciplinary team (MDT) input, with the mainstay of treatment being a wide surgical resection to remove the whole tumour, but this can be challenging due to the infiltrative nature of MFSs through fascial planes. Appropriate pre-operative imaging is therefore essential for surgical planning. Currently, MRI imaging is the modality of choice to assess the soft-tissue extent of MFSs; however, it does not always reliably predict tumour extent, especially when an MRI shows high-signal curvilinear projections, known as "tails", which often represent tumour extension and increase the risk of positive margins and local recurrence. Methods: This feasibility study therefore aimed to investigate whether the addition of an FDG PET-MRI and DWI MRI is superior for the local staging of MFSs compared to a standard MRI, and to assess its practicality for clinical use. Results: Of the eight patients recruited, six completed the required scans, proceeded to surgery, and were included in the data analyses. Five of the six patients had close (<2 mm) or positive margins requiring re-excision. Conclusions: Our results show that combining an FDG-PET and DWI MRI may offer a more accurate local staging of MFSs than a conventional MRI; however, a larger prospective trial is needed to further investigate this pilot data. Nevertheless, this novel feasibly study demonstrates the potential use of PET-MRI and DWI for improving pre-operative planning prior to the surgical resection of MFSs.

Clinician's primer for soft tissue sarcomas: Nuances of histologic subtypes

Soft tissue sarcomas are a rare group of mesenchymal malignancies, with greater than 100 histologic subtypes. Advancements in understanding these subtypes has enabled histology-tailored management. This primer describes the workup and management of generalized soft tissue sarcomas of the extremity, trunk, and retroperitoneum while also highlighting the unique attributes of many subtypes. The subtypes chosen for review include those that are most common as well as those demonstrating unique behaviors or targets for management. The focus is on initial management of localized disease; however, for situations in which novel systemic agents have been discovered, the treatment of metastatic disease is discussed. This report is a reference to be used in addition to other comprehensive reviews, such as guidelines from the National Comprehensive Cancer Network, the European Society for Medical Oncology, and the American Society for Radiation Oncology. It is not a substitute for referral to an expert sarcoma center for critical pathology review and management by an experienced team. Importantly, patients who are treated at expert sarcoma centers have better outcomes than those who are not.

Diagnostic conundrum of Superficial CD34-positive fibroblastic tumor (SCPFT): a series of five cases

Superficial CD34-positive fibroblastic tumor (SCPFT) is an extremely rare neoplasm with an indolent behavior. It was incorporated for the first time in the fifth edition of the World Health Organization (WHO) classification in the rarely metastasizing category of soft tissue tumors with an intermediate biological potential. It is a challenging clinical entity coupled with a pathological dilemma due to moderate to marked pleomorphism in tumor cells mimicking various sarcomas. Histologically, these tumors appear to be malignant at the outset but atypical mitosis or necrosis are rarely seen. These cells show diffuse positivity for CD34 and are focally positive for Pan-cytokeratin which further aids in diagnosis. Some of the SCPFT harbor PRDM10 rearrangement; however, the diagnosis does not require molecular testing. We are discussing a series of five cases of SCPFT, highlighting the diagnostic histological and immune-histochemical features of this enigmatic entity. We pen down the series as an accurate histopathological diagnosis of SCPFT is undoubtedly a key to prevent its misdiagnosis as a malignant tumor with drastically different clinical implications.

Giant Myxofibrosarcoma in the Lower Limb: An Overview of Diagnostic and Clinical Management

Myxofibrosarcoma (MFS), an aggressive soft tissue sarcoma, is one of the undifferentiated pleomorphic sarcomas; it has a low incidence, affecting people in the sixth to eighth decades of life. It usually involves the extremities and is painless with a slow-growing pattern. Based on the case of a 52-year-old female patient who presented with a painful, massive, rapid-growing, ulcerated tumor of the anterior surface of the left thigh, we performed a literature review regarding the current standard of care for patients with MFS. Computed tomography examination, followed by magnetic resonance imaging and surgical biopsy with histopathological examination, confirmed the diagnosis and the presence of lung and inguinal lymph node metastases. Due to the rapid-growing pattern and the local aggressiveness, our tumor board team recommended emergency excisional surgery, with subsequent reconstructive procedures followed by referral to an oncological center. This review emphasizes the importance of proper and rapid diagnosis, followed by multidisciplinary management, for MFS cases with atypical presentation and distal metastases to improve overall outcomes.

Myxofibrosarcoma: Outcomes, Prognostic Factors, and Role of Neoadjuvant Radiation Therapy

Purpose

Myxofibrosarcoma (MFS) is a subtype of soft tissue sarcoma with a highly infiltrative growth pattern that leads to a higher risk of inadvertent positive surgical margins and local relapse. Poorly defined tumor margins also pose a challenge for radiation therapy (RT) planning, in terms of treatment volumes and administration of pre- versus postoperative RT. This study aims to evaluate local control and patterns of recurrence in patients with MFS treated with neoadjuvant RT followed by definitive surgical excision.

Methods and Materials

Multiple institutional databases were retrospectively searched for patients diagnosed with MFS between 2013 and 2021 who were exclusively treated with preoperative RT followed by definitive surgery at our institution. The endpoints of the study were defined as local tumor recurrence, distant metastasis, and death after the date of definitive surgery.

Results

Forty-nine patients met the inclusion criteria and were included in the final study. The median age at diagnosis was 67 years, and 71% of patients were male. The tumor was superficially located in 63% of patients, and the mean tumor size at presentation was 7.8 cm. All patients received neoadjuvant RT and completed their planned course of treatment. Neoadjuvant chemotherapy was administered in 22% of patients. Inadvertent excision (IE) before definitive treatment was performed in 25 patients (51%), 84% of which had superficially located tumors. All margins were assessed using frozen section analysis at the time of definitive surgery, and 100% of patients had negative surgical margins, with 25% having no residual tumor. With a median follow-up of 4.7 years, the 5-year local control rate was 87%, and 5-year overall survival was 98%. Tumor depth was associated with distant metastasis (P < .01).

Conclusions

Despite the infiltrative nature of MFS, preoperative RT followed by definitive surgical excision, especially in the setting of a reliable frozen section margin analysis, was associated with excellent local control.

A rare presentation of primary cardiac myxofibrosarcoma: Case report and literature review

BACKGROUND

Primary cardiac myxofibrosarcoma is a rare and aggressive malignancy, with the majority of approaching strategies relying on case reports. This article provides insights into its diagnosis and treatment.

CASE PRESENTATION

This paper presents the case of a 40-year-old man with sudden onset hemoptysis, leading to the diagnosis of primary cardiac myxofibrosarcoma. Treatment involved open-heart surgery to excise the left atrium tumor, followed by 6 cycles of adjuvant chemotherapy. Unfortunately, brain metastasis developed, leading to the patient's death 1 year after initial diagnosis.

CONCLUSION

Primary cardiac myxofibrosarcoma remains a clinical challenge with an unfavorable prognosis. Early diagnosis through advanced imaging is crucial, and research is needed to explore innovative treatments. This case underscores the complexities of managing this rare cardiac malignancy and highlights the necessity for ongoing investigations to enhance patient outcomes.

Epidemiology and survival factors of appendicular myxofibrosarcoma: a SEER-retrospective study

Background

The low incidence of myxofibrosarcoma (MFS) makes high power studies difficult to perform. Demographic and prognostic factors for MFS and how they differ from all extremity soft tissue sarcomas (STS) are not well understood. The purpose of this study was to characterize a large cohort of patients with MFS and evaluate epidemiologic and survival factors when compared to all STS.

Materials and methods

We performed a retrospective review of the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2015 to identify 1,440 patients diagnosed with MFS and 12,324 with STS. Survival curves were creased using Kaplan-Meier, and Cox regression analyses were performed to identify hazard ratios (HRs).

Results

Overall survival was greater for STS than MFS (79% vs. 67%). Patients with MFS had a higher average age at diagnosis than STS (62 vs. 56), and older age was strongly associated with decreased survivorship for MFS (HR = 7.94). A greater proportion of patients under 30 diagnosed with MFS were female when compared to STS (49.6% vs. 45.4%). The incidence of MFS and STS increased over the 15-year period, with MFS increasing at a greater rate than STS (1.25% vs. 2.59%). Survival increased for patients diagnosed after 2008 for both STS (9.4%) and MFS (13.2%).

Conclusions

There are differences between patient demographics and survival factors when comparing MFS to all STS. Monitoring changes in demographic and survival trends for rare STS subtypes like MFS is important to improve diagnostic algorithms and treatment options.

A novel patient-derived immortalised cell line of myxofibrosarcoma: a tool for preclinical drugs testing and the generation of near-patient models

BACKGROUND

Myxofibrosarcoma is a rare malignant soft tissue sarcoma characterised by multiple local recurrence and can become of higher grade with each recurrence. Consequently, myxofibrosarcoma represents a burden for patients, a challenge for clinicians, and an interesting disease to study tumour progression. Currently, few myxofibrosarcoma preclinical models are available.

METHODS

In this paper, we present a spontaneously immortalised myxofibrosarcoma patient-derived cell line (MF-R 3). We performed phenotypic characterization through multiple biological assays and analyses: proliferation, clonogenic potential, anchorage-independent growth and colony formation, migration, invasion, AgNOR staining, and ultrastructural evaluation.

RESULTS

MF-R 3 cells match morphologic and phenotypic characteristics of the original tumour as 2D cultures, 3D aggregates, and on the chorioallantoic membrane of chick embryos. Overall results show a clear neoplastic potential of this cell line. Finally, we tested MF-R 3 sensitivity to anthracyclines in 2D and 3D conditions finding a good response to these drugs.

CONCLUSIONS

In conclusion, we established a novel patient-derived myxofibrosarcoma cell line that, together with the few others available, could serve as an important model for studying the molecular pathogenesis of myxofibrosarcoma and for testing new drugs and therapeutic strategies in diverse experimental settings.

Is the Thickness of the Margin Associated With Local Recurrence and Survival in Patients With Myxofibrosarcoma?

BACKGROUND

Myxofibrosarcoma (MFS) is a spectrum of aggressive soft tissue fibroblastic neoplasms characterized by variable myxoid stroma, pleomorphism, and a distinctive curved vascular pattern; these tumors are associated with a high likelihood of recurrence. Better local tumor control (a tumor-free margin) is believed to be important to minimize the risk of recurrence, but the effect of surgical resection margin status on local recurrence and survival in MFS is not as well-characterized as it might be.

QUESTIONS/PURPOSES

(1) Is margin width associated with local recurrence? (2) Is there a relationship between greater margin thickness and improved overall and disease-free survival (DFS)? (3) Is worsening French Federation of Cancer Centers grade associated with local recurrence and poorer overall survival?

METHODS

Using a database of patients with bone and soft tissue tumors at a tertiary university hospital, we retrospectively reviewed the medical records of 282 patients who had soft tissue sarcomas and who had been surgically treated by a multidisciplinary bone and soft tissue tumor care team between January 2010 and December 2021. Of these 282 patients, 38 were identified as having MFS. Patients who received surgical care for MFS outside our institution (unplanned resection) (four patients) and whose surgical margins were not reported as microscopic numerical data (10) were excluded from the analysis. We estimated survival and local recurrence and examined factors potentially influencing these outcomes. Patient demographics, tumor characteristics, surgical margin distance (in mm), and disease-related outcomes were recorded. The minimum follow-up was 3 months (median 41.5 months, range 3 to 128 months).

RESULTS

Overall 1-year local recurrence-free rates were 66.7% (95% CI 50% to 88%). Patients with positive margins were more likely to have local recurrence than patients with negative margins (HR 10.91 [95% CI 2.61 to 45.66]; p = 0.001). Patients with an inadequate margin (positive margin or a negative margin of 1 mm or less) had a greater risk of local recurrence (HR 9.96 [95% CI 1.22 to 81.44]; p = 0.032). Patients with positive margins or margins less than or equal to 1 mm had worse 2-year local recurrence-free survival than did those with margins of greater than 1 mm (46.9% [95% CI 16% to 76%] versus 91.7% [95% CI 75% to 100%]; p = 0.005). The mean overall survival was 98 months (95% CI 77.2 to 118.8). The Kaplan-Meier overall 1-, 2- and 5-year estimated rates of survival were 88% (95% CI 75% to 100%), 79.2% (95% CI 64.5% to 97.2%), and 73.5% (95% CI 57.2 % to 94.5%), respectively. Positive surgical margins were associated with decreased overall survival (HR 6.96 [95% CI 1.39 to 34.89]; p = 0.018). There was a mean DFS time of 4.25 months (95% CI 0.92 to 7.59) in microscopically positive patients, 75.5 months (95% CI 37.47 to 113.53) in patients with margins 1 mm or less, and 118 months (95% CI 99.23 to 136.77) in patients with margins over 1 mm. There was a statistical difference between DFS times according to surgical margin classification (p < 0.001). With the numbers we had, we could not detect any difference between the histologic grades determined by the French Federation of Cancer Centers grading system in terms of local recurrence (HR 3.80 [95% CI 0.76 to 18.94]; p = 0.103) and overall survival (HR 6.91 [95% CI 0.79 to 60.13]; p = 0.080). Tumor size was the prognostic factor associated with a higher local recurrence rate among all factors analyzed as univariate (HR 1.18 [95% CI 1.05 to 1.32]; p = 0.004).

CONCLUSION

A surgical procedure with a sufficient negative surgical margin distance appears to be associated with a lower proportion of patients who experience a local recurrence and is associated with overall patient survival. It is difficult to define what a sufficient margin is, but in our patients, it appears to be greater than 1 mm.Level of Evidence Level III, therapeutic study.

Modeling Myxofibrosarcoma: Where Do We Stand and What Is Missing?

Myxofibrosarcoma (MFS) is a malignant soft tissue sarcoma (STS) that originates in the body's connective tissues. It is characterized by the presence of myxoid (gel-like) and fibrous components and typically affects patients after the fifth decade of life. Considering the ongoing trend of increasing lifespans across many nations, MFS is likely to become the most common musculoskeletal sarcoma in the future. Although MFS patients have a lower risk of developing distant metastases compared with other STS cases, MFS is characterized by a high frequency of local recurrence. Notably, in 40-60% of the patients where the tumor recurs, it does so multiple times. Consequently, patients may undergo multiple local surgeries, removing the risk of potential amputation. Furthermore, because the tumor relapses generally have a higher grade, they exhibit a decreased response to radio and chemotherapy and an increased tendency to form metastases. Thus, a better understanding of MFS is required, and improved therapeutic options must be developed. Historically, preclinical models for other types of tumors have been instrumental in obtaining a better understanding of tumor development and in testing new therapeutic approaches. However, few MFS models are currently available. In this review, we will describe the MFS models available and will provide insights into the advantages and constraints of each model.

Efficacy and Safety of Adjuvant Radiotherapy in Re-excised Soft-tissue Sarcoma After Unplanned Resection

INTRODUCTION

The objective of this study was to evaluate the efficacy and safety of adjuvant radiotherapy (aRT) in patients with soft-tissue sarcoma (STS) re-excised after unplanned tumor resection (UPR).

MATERIALS AND METHODS

From 2000 to 2015, we retrospectively evaluated patients with STS of limb or trunk who underwent post-UPR re-excision in our expert center and received or not aRT.

RESULTS

Median follow-up was 121 months (IQR 94-165). Among the 145 patients, 37 were not treated with aRT (no-RT) and 108 received aRT with a median radiation dose of 50 Gy (IQR 50-60). At 10 years, patients in the aRT and no-RT groups showed a cumulative incidence of local failure (10y-LF) of 14.7% and 37.7%, and a local recurrence-free survival (10y-LRFS) of 61.3% and 45.8%, respectively. Multivariate analysis identified aRT and age ≥70 years as independent predictors of both LF and LRFS, while grade 3 and deep-seated tumor were independent predictors of LRFS. In overall population, 10-year distant metastasis-free survival (10y-DMFS) and overall survival (10y-OS) were 63.7% and 69.4%. In multivariate analyses, age ≥70 years, grade 3, and deep-seated lesion were associated with shorter DMFS and OS. Acute severe adverse events were not significantly increased in aRT group (14.8% vs. 18.1%, P = .85) but dramatically increased if radiation dose exceeded 50 Gy (risk ratio 2.96 compared to ≤50 Gy, P = .04).

CONCLUSION

In STS patients re-excised after UPR, 50 Gy aRT was safe and associated with reduced LF and longer LRFS. It seems to be beneficial even in absence of residual disease or in absence of initial adverse prognostic factors.

Evaluation of the Effect of Photodynamic Therapy on CAM-Grown Sarcomas

Resection margin adequacy plays a critical role in the local control of sarcomas. Fluorescence-guided surgery has increased complete resection rates and local recurrence-free survival in several oncological disciplines. The purpose of this study was to determine whether sarcomas exhibit sufficient tumor fluorescence (photodynamic diagnosis (PDD)) after administration of 5-aminolevulinic acid (5-ALA) and whether photodynamic therapy (PDT) has an impact on tumor vitality in vivo. Sixteen primary cell cultures were derived from patient samples of 12 different sarcoma subtypes and transplanted onto the chorio-allantoic membrane (CAM) of chick embryos to generate 3-dimensional cell-derived xenografts (CDXs). After treatment with 5-ALA, the CDXs were incubated for another 4 h. Subsequently accumulated protoporphyrin IX (PPIX) was excited by blue light and the intensity of tumor fluorescence was analyzed. A subset of CDXs was exposed to red light and morphological changes of both CAMs and tumors were documented. Twenty-four hours after PDT, the tumors were excised and examined histologically. High rates of cell-derived engraftments on the CAM were achieved in all sarcoma subtypes and an intense PPIX fluorescence was observed. PDT of CDXs resulted in a disruption of tumor-feeding vessels and 52.4% of CDXs presented as regressive after PDT treatment, whereas control CDXs remained vital in all cases. Therefore, 5-ALA mediated PDD and PDT appear to be promising tools in defining sarcoma resection margins (PDD) and adjuvant treatment of the tumor bed (PDT).

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.

[Myxosarcoma in the cervical region in a teddy bear hamster (Mesocricetus auratus)]

This case report describes a rare case of a myxosarcoma in a 1-year-old teddy bear hamster presenting with a mass in the cervical region. The fine-needle aspiration cytology revealed high numbers of pleomorphic spindle-shaped cells found in a viscous mucinous background. The presumptive cytological diagnosis was malignant spindle cell neoplasia based on marked criteria of malignancy of the mesenchymal cell population. The abundant matrix in the background was suggestive of a myxosarcoma. The hamster died during surgery and a necropsy was performed. Histopathology was in complete agreement with the cytological report. Immunohistochemistry revealed the tumour to be vimentin positive with alcian-blue positive matrix and confirmed the presumptive diagnosis of a myxosarcoma. This case shows that fine-needle aspiration cytology can be utilized as a minimally invasive diagnostic tool in small mammals to classify mass lesions. However, so far little is known about the biological behaviour of myxosarcoma in the hamster as case descriptions are rare.

Primary thyroid gland myxofibrosarcoma: a case report and review of the literature

Background

Myxofibrosarcoma is a common soft tissue sarcoma of the extremities, which occurs very rarely in the thyroid gland.

Case presentation

We report the case of a 61-year-old male who presented with a swelling of the left side of the neck and a newly emerged hoarseness. Ultrasound depicted a hypoechoic thyroid nodule with microcalcifications that was highly suspicious for malignancy. He underwent a left hemithyroidectomy. Histopathological examination and immunohistochemical studies revealed a myxofibrosarcoma of the thyroid gland.

Conclusion

Myxofibrosarcoma of the thyroid gland is extremely rare. The diagnosis is based on histopathological features. Radical surgery achieving tumor-free resection margins remains the only chance for cure. However, the role of radiotherapy and/or chemotherapy is still under debate. Due to their high tendency for locoregional recurrence, a close follow-up after surgery is mandatory.

Epidemiologic Survey of Myxofibrosarcoma Using Data from the Bone and Soft Tissue Tumor Registry in Japan

BACKGROUND

Myxofibrosarcoma is a common sarcoma among older patients, with locally infiltrative behavior and a predilection for local postoperative recurrence. Some studies have reported the factors affecting prognosis, although only a few have mentioned the previous staging classification systems. This study investigated the clinical overview and prognosis of myxofibrosarcoma to determine the optimal treatment.

METHODS

This retrospective study analyzed the records of 349 patients with myxofibrosarcoma in the nationwide Bone and Soft Tissue Tumor Registry in Japan from 2006 to 2015. Clinical features, treatment options, and patient outcomes were investigated.

RESULTS

Ultimately, 349 patients were identified. The overall survival rates were 93.1% at 2 years and 84.3% at 5 years. A multivariate analysis was performed using the Cox proportional hazards model. The study identified four significant prognostic factors for survival: tumor size, depth, compartment status, and location. The prognostic score was calculated by summing the scores of all the factors. The overall survival rate was 69.3% at 5 years for the patients with prognostic scores of 6 or higher. Conversely, the patients with prognostic scores of 2 or lower had a survival rate of 95.6% at 5 years.

CONCLUSIONS

Among myxofibrosarcomas, those larger than 5 cm, deep-seated, invaded into the external compartment, or in axial body parts were associated with a significantly worse prognosis. Adjuvant radiotherapy and chemotherapy did not contribute significantly to a better prognosis. Previous staging classification systems are impractical for prognosis prediction. Therefore, new classifications are needed. Further research on new treatment methods for patients with a poor prognosis will be crucial in the future.

Brain metastasis from a thoracic myxofibrosarcoma: A case report and literature review

Background:

Myxofibrosarcoma (MFS) is a type of sarcoma that mainly affects elderly people; it represents only 5% of all sarcomas and shows no line of differentiation. Intracranial MFS is a rare condition. At present, limited data exist regarding brain metastasis from MFS. This article reports a case of MFS and reviews the literature regarding MFS metastasis.

Case Description:

We report a case of brain metastasis from chest wall MFS. The patient was diagnosed with an anterior thoracic MFS and underwent surgery and radiotherapy. One year later, he noticed a tumor on his left shoulder, and more than 1 year thereafter, bilateral lung metastasis was observed. Twelve months after lung metastasis, he presented to the emergency department and underwent contrast-enhanced magnetic resonance imaging, which demonstrated a left frontal tumor suggestive of brain metastasis. Since the main hypothesis was a sarcoma metastasis at the location close to the left motor area, and the patient had a good Karnofsky performance scale, the patient underwent neuronavigation-guided surgery. After surgery, the patient developed Grade III hemiparesis and aphasia. Brain tumor histopathology confirmed a malignant neoplasm with osteosarcomatous differentiation and metastasis from MFS.

Conclusion:

We report a rare case of MFS metastasis. To the best of our knowledge, this is the eighth case of intracerebral metastasis from MFS.

Preoperative hypofractionated radiotherapy for soft tissue sarcomas: a systematic review

BACKGROUND

Soft tissue sarcomas (STS) represent a diverse group of rare malignant tumors. Currently, five to six weeks of preoperative radiotherapy (RT) combined with surgery constitute the mainstay of therapy for localized high-grade sarcomas (G2-G3). Growing evidence suggests that shortening preoperative RT courses by hypofractionation neither increases toxicity rates nor impairs oncological outcomes. Instead, shortening RT courses may improve therapy adherence, raise cost-effectiveness, and provide more treatment opportunities for a wider range of patients. Presumed higher rates of adverse effects and worse outcomes are concerns about hypofractionated RT (HFRT) for STS. This systematic review summarizes the current evidence on preoperative HFRT for the treatment of STS and discusses toxicity and oncological outcomes compared to normofractionated RT.

METHODS

We conducted a systematic review of clinical trials describing outcomes for preoperative HFRT in the management of STS using PubMed, the Cochrane library, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Embase, and Ovid Medline. We followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Trials on retroperitoneal sarcomas, postoperative RT, and hyperthermia were excluded. Articles published until November 30th, 2021, were included.

RESULTS

Initial search yielded 94 articles. After removal of duplicate and ineligible articles, 13 articles qualified for analysis. Eight phase II trials and five retrospective analyses were reviewed. Most trials applied 5 × 5 Gy preoperatively in patients with high-grade STS. HFRT courses did not show increased rates of adverse events compared to historical trials of normofractionated RT. Toxicity rates were mostly comparable or lower than in trials of normofractionated RT. Moreover, HFRT achieved comparable local control rates with shorter duration of therapy. Currently, more than 15 prospective studies on HFRT + / - chemotherapy are ongoing.

CONCLUSIONS

Retrospective data and phase II trials suggest preoperative HFRT to be a reasonable treatment modality for STS. Oncological outcomes and toxicity profiles were favorable. To date, our knowledge is mostly derived from phase II data. No randomized phase III trial comparing normofractionated and HFRT in STS has been published yet. Multiple ongoing phase II trials applying HFRT to investigate acute and late toxicity will hopefully bring forth valuable findings.

Establishment and characterization of NCC-MFS6-C1: a novel patient-derived cell line of myxofibrosarcoma

Myxofibrosarcoma (MFS) is a rare and aggressive mesenchymal malignancy characterized by complex karyotypes with heterogeneous clinical features. The standard treatment for primary MFS is curative resection; however, the utility of systemic chemotherapy and radiotherapy has not been established. Although patient-derived cancer cell lines are a key bioresource for developing novel therapies, the number of MFS cell lines available from public cell banks is limited by the rarity of the disease, and large-scale drug screening has not yet been performed. To address this issue, we aimed to establish and characterize a novel MFS cell line. We successfully established a cell line, NCC-MFS6-C1, which harbors genetic abnormalities common in MFS and exhibits aggressive phenotypes such as continuous growth, spheroid formation, and invasion in tissue culture conditions. We performed drug screening using NCC-MFS6-C1 along with five MFS cell lines established in our laboratory and clarified the response spectrum of 214 existing anticancer agents. We found that two anticancer agents, gemcitabine and romidepsin, showed considerable antiproliferative effects, and these observations were concordant with the findings of our previous report, in which these agents attenuated the proliferation of five previously reported MFS cell lines. We conclude that NCC-MFS6-C1 is a useful resource for studying MFS.

Myxofibrosarcoma landscape: diagnostic pitfalls, clinical management and future perspectives

Myxofibrosarcoma (MFS) is a common entity of adult soft tissue sarcomas (STS) characterized by a predilection of the extremities and a high local recurrence rate. Originally classified as a myxoid variant of malignant fibrous histiocytoma, this musculoskeletal tumor has been recognized since 2002 as a distinct histotype showing a spectrum of malignant fibroblastic lesions with myxoid stroma, pleomorphism and curvilinear vessels. Currently, the molecular pathogenesis of MFS is still poorly understood and its genomic profile exhibits a complex karyotype with a number of aberrations including amplifications, deletions and loss of function. The diagnosis is challenging due to the unavailability of specific immunohistochemical markers and is based on the analysis of cytomorphologic features. The mainstay of treatment for localized disease is represented by surgical resection, with (neo)-adjuvant radio- and chemotherapy. In the metastatic setting, chemotherapy represents the backbone of treatments, however its role is still controversial and the outcome is very poor. Recent advent of genomic profiling, targeted therapies and larger enrollment of patients in translational and clinical studies, have improved the understanding of biological behavior and clinical outcome of such a disease. This review will provide an overview of current diagnostic pitfalls and clinical management of MFS. Finally, a look at future directions will be discussed.

Management of Myxofibrosarcoma and Undifferentiated Pleomorphic Sarcoma

Undifferentiated pleomorphic sarcoma (UPS) and myxofibrosarcoma (MFS) are genomically complex tumors commonly diagnosed in the extremities or trunk of elderly patients. They likely represent a spectrum of disease differentiated by myxoid stroma and curvilinear vessels observed in MFS but not in UPS. Limb-sparing surgery is the standard of care although the infiltrative nature of MFS mandates wider resection margins than are necessary for UPS. UPS are conversely associated with high risks of distal recurrence, often prompting recommendations for adjuvant chemotherapy. In both histologies, anthracycline-based therapies or gemcitabine and docetaxel are used to manage advanced disease; immunotherapy may be of benefit in a subset of patients.

Case Report: Inguinal Myxofibrosarcoma Arising From the Surgical Site of Resected Squamous Cell Carcinoma

Myxofibrosarcoma (MFS) is a rare soft tissue sarcoma that originates in the mesenchymal tissue and occurs mainly in the limbs of elderly patients. Herein, we present the case of a 64-year-old woman who underwent extensive left vulvar resection and bilateral lymphadenectomy for vulvar squamous cell carcinoma 6 months previously. A mass was found again at the original surgical site of the left groin 3 months prior, and its size had increased significantly in the past 1 month, with ulceration and pus. Magnetic resonance imaging (MRI) showed a 10-cm mass in the left groin area; fluoro18-labeled deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) showed a marked increase in mass metabolism in the left groin area, which was highly suspected to be a recurrence of squamous cell carcinoma. Subsequently, the patient underwent surgery and the postoperative pathology and immunohistochemistry confirmed MFS. In conclusion, MFS has rarely been reported to arise from the surgical site of squamous cell carcinoma. Our case study demonstrates that MFS should be included in the differential diagnosis of superficial masses in patients with a prior surgical history who present with a soft tissue mass at the surgical site, especially for recently developed rapidly increasing masses. This study aimed to systematically review the clinical features, diagnosis, differential diagnosis, treatment, and prognosis of this disease based on our case and related published literature and to provide clinicians with a broader perspective on the differential diagnosis of soft tissue tumors.

Overall Survival of Patients with Myxofibrosarcomas: An Epidemiological Study

Myxofibrosarcoma (MFS) is a rare mesenchymal soft tissue sarcoma type, with a high local recurrence (LR) rate. Robust epidemiological data on MFS are lacking. We, therefore, aimed to identify prognostic factors and describe real-life outcomes of a large cohort of 908 MFS patients obtained from the nationwide database of the Netherlands Cancer Registry and diagnosed between 2002 and 2019. Median Overall survival (OS) was 155 (range 0.1-215) months, with a five-year OS of 67.7%. No improvement of OS was found over time. Multivariable Cox regression survival analysis demonstrated known prognostic factors for OS, such as older age, tumour size, and histological grade with the addition of sex. Surgery at sarcoma expertise centres, instead of general hospitals, was associated with better OS outcomes. In a subcohort of 177 patients, 39% developed LR with a median time to recurrence of 20 months. From LR on, the median OS was 64.0 months (CI 95% 38.5-89.5). In 28%, distant metastases were diagnosed with a median OS of 34.3 months (CI 95% 28.8-39.8) after diagnosis of the primary tumour. In this largest nationwide cohort so far, survival outcomes and recurrence rates for MFS patients did not improve over time, emphasizing the need to improve treatment strategies and suggesting a role for sarcoma expertise centres.

Sinonasal/basicranial myxofibrosarcoma: a report of 6 surgical cases combined with a literature review

OBJECTIVE

The aim of this study was to report 6 cases of sinonasal/basicranial myxofibrosarcoma and review demographic data, clinical symptoms, diagnostic methods, therapeutic methods, and prognosis on this subject in the literature.

METHODS

We conducted a retrospective analysis of six patients referred to our hospital during a 10-year period from 2010 to 2020.

RESULTS

In this series, there were four males and two females. The tumours originated from the maxillary sinus in all six cases. The symptoms were nonspecific, and all patients underwent endoscopic resection alone or combined with open resection. The postoperative period was uneventful. All patients were diagnosed with myxofibrosarcoma. After a median follow-up period of 36 (6-52) months, the recurrence rate of MFS was 66.7% (4/6), and the mortality rate was 50% (3/6).

CONCLUSION

Sinonasal/basicranial MFS is a rare neoplasm, and the most common primary site is the maxillary sinus. When diagnosing MFS, osteolysis may help rule out benign lesions. So far surgery is the mainstay of treatment for sinonasal/basicranial MFS. Our surgical strategy using endoscopic resection or endoscopic resection combined with open resection to achieve a negative surgical margin and using re-excision operations to treat relapsed cases may be recommended to rhinologists who treat MFS. Prospective randomised trials are needed to study the role of chemotherapy, radiotherapy, and our surgical strategy for sinonasal/basicranial MFS. Diagnosing patients at an earlier stage and better patient compliance with follow-up plans may improve the prognosis of patients.

Oncological Outcomes in Patients with Appendicular Myxofibrosarcomas: A Retrospective Study

BACKGROUND

Myxofibrosarcoma (MFS) is notorious for its infiltrative growth pattern, making wide excisions difficult to achieve. Our objective was to assess the impact of surgical margins and other factors that affected rates of local recurrence (LR), distant metastasis (DM), and overall survival (OS) of individuals undergoing resection for MFS.

METHODS

We retrospectively reviewed the medical records of 209 patients with appendicular soft tissue sarcomas between January 2012 and June 2018. Of these, 29 patients (14%) were diagnosed with myxofibrosarcoma. These patients underwent a total of 33 resections. The pathological analyses were conducted by an experienced musculoskeletal (MSK) pathologist. Demographics data, operative details, adjuvant therapy, and oncological outcomes were assessed.

RESULTS

Of the 29 patients (33 resections), the overall LR rate was 24% (7/29) and the 2-year LR rate was 17% (5/29). Factors associated with negative oncological outcomes were as follows: tumor size ≤10 cm (2-year local recurrence-free rates (LRFRs), 65%; 95% CI, 44-86%; p=0.02) and positive surgical margins grouped with surgical margins ≤0.1 cm (hazard ratio (HR), 11.74; 95% CI, 1.41-97.74; p=0.02). Chemotherapy and radiotherapy together increased the 2-year LRFR (LRFR, 100%; 95% CI, 100%, p=0.001). Two-year DM and OS rates were 15% and 79%, respectively. Female gender was a predictor of distant metastasis. Local recurrence had a negative impact on overall survival. Intraoperative analysis of resection margin accuracy was 75% (12/16) when non-MSK pathologists were involved but 100% accurate (12/12) when analyzed by an MSK pathologist.

CONCLUSION

Myxofibrosarcomas showed high LR rates after treatment. Close margins (≤0.1 cm) should be considered as a risk factor for LR, and LR is associated with negative overall survival. Neoadjuvant therapy in terms of combined chemotherapy and radiation therapy associates with decreased LR rates. If intraoperative assessment of margins is to be done, it should be performed by an experienced MSK pathologist.

Idiopathic and radiation-induced myxofibrosarcoma in the head and neck-case report and literature review

BACKGROUND

Myxofibrosarcoma (MFS), especially radiation-Induced MFS (RIMFS) in the head and neck, is an extremely rare malignant fibroblastic tumor. The diagnosis and treatment of MFS remain great challenges. In the present study, we presented one case of RIMFS. Combined with previous literature, the clinical features, essentials of diagnosis, and treatment modalities of MFS in the head and neck were reviewed to better understand this rare entity.

CASE PRESENTATION

We reported a case of RIMFS under the left occipital scalp in a 20-year-old girl with a history of medulloblastoma surgery and radiotherapy in 2006. A total tumor resection was performed with preservation of the overlying scalp the underlying bone, and no adjuvant therapy was administered after the first operation. The postoperative pathological diagnosis was high-grade MFS. The tumor relapsed 6 months later, and then, a planned extensive resection with negative surgical margins was carried out, followed by radiotherapy. No relapse occurred in a 12-month postoperative follow-up.

CONCLUSIONS

Planned gross total resection (GTR) with negative margins is the reasonable choice and footstone of other treatments for MFS. Ill-defined infiltrated borders and the complicated structures make it a great trouble to achieve total resection of MFS in the head and neck, so adjuvant radiotherapy and chemotherapy seem more necessary for these lesions.

RSF1 requires CEBP/β and hSNF2H to promote IL-1β-mediated angiogenesis: the clinical and therapeutic relevance of RSF1 overexpression and amplification in myxofibrosarcomas

Myxofibrosarcoma is genetically complex and lacks effective nonsurgical treatment strategies; thus, elucidation of novel molecular drivers is urgently needed. Reanalyzing public myxofibrosarcoma datasets, we identified mRNA upregulation and recurrent gain of RSF1 and characterized this chromatin remodeling gene. Myxofibrosarcoma cell lines were employed to elucidate the oncogenic mechanisms of RSF1 by genetic manipulation and two IL-1β-neutralizing antibodies (RD24, P2D7KK), highlighting the regulatory basis and targetability of downstream IL-1β-mediated angiogenesis. Tumor samples were assessed for RSF1, IL-1β, and microvascular density (MVD) by immunohistochemistry and for RSF1 gene status by FISH. In vivo, RSF1-silenced and P2D7KK-treated xenografts were analyzed for tumor-promoting effects and the IL-1β-linked therapeutic relevance of RSF1, respectively. In vitro, RSF1 overexpression promoted invasive and angiogenic phenotypes with a stronger proangiogenic effect. RT-PCR profiling identified IL1B as a top-ranking candidate upregulated by RSF1. RSF1 required hSNF2H and CEBP/β to cotransactivate the IL1B promoter, which increased the IL1B mRNA level, IL-1β secretion and angiogenic capacity. Angiogenesis induced by RSF1-upregulated IL-1β was counteracted by IL1B knockdown and both IL-1β-neutralizing antibodies. Clinically, RSF1 overexpression was highly associated with RSF1 amplification, IL-1β overexpression, increased MVD and higher grades (all P ≤ 0.01) and independently predicted shorter disease-specific survival (P = 0.019, hazard ratio: 4.556). In vivo, both RSF1 knockdown and anti-IL-1β P2D7KK (200 μg twice weekly) enabled significant growth inhibition and devascularization in xenografts. In conclusion, RSF1 overexpression, partly attributable to RSF1 amplification, contributes a novel proangiogenic function by partnering with CEBP/β to cotransactivate IL1B, highlighting its prognostic, pathogenetic, and therapeutic relevance in myxofibrosarcomas.

Impact of histological subtype on radiological and pathological response after neoadjuvant radiotherapy in soft tissue sarcoma

BACKGROUND

Evaluation of response to neoadjuvant radiotherapy (NART) does not consider soft tissue sarcoma (STS) heterogeneity. We aimed to investigate radiological and pathological response of 4 major histotypes.

METHODS

Extremity or trunk STS patients who received 50 Gy NART between 2009 and 2020 were retrospectively included. Relative variation in tumor size (RVTS) and pathological response were reported in the overall population and in undifferentiated pleomorphic sarcoma (UPS), myxofibrosarcoma (MFS), myxoid liposarcoma (MLS) and synovial sarcoma (SS) patients to identify response modalities of each histotype.

RESULTS

Among the 121 included patients, 49, 19, 13 and 11 presented UPS, MFS, MLS and SS. Median RVTS were 0% (IQR -18-+18), +8% (IQR 0-+24), -12% (IQR -20-3) and -11% (IQR -15-9), respectively (p = 0.001). Median viable cells were 10%, 60%, 20% and 70% (p = 0.007). In overall population, pathological complete response and median necrosis were 27.7% and 10% without significant correlation to histotype (p = 0.18 and 0.06). Nineteen (38.8%) UPS specimens presented cysts that were emptied during the sampling process and distorted the microscopic response evaluation. Infiltrative growth pattern was observed in 28% and 38.9% UPS and MFS patients. Five (38.5%) MLS presented mature adipocytes without proven prognostic value. Cysts were observed in 36% of SS specimens. In the absence of initial tumor limits, the great viable cellularity of SS may be overestimated by their nodular aspect.

CONCLUSION

After NART, we highlighted disparate response of UPS, frequent progression of MFS, and confirmed MLS and SS radiosensitivity. Response must be interpreted with caution and consider the histotype-specific patterns.

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.

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.

OSmfs: An Online Interactive Tool to Evaluate Prognostic Markers for Myxofibrosarcoma

Myxofibrosarcoma is a complex genetic disease with poor prognosis. However, more effective biomarkers that forebode poor prognosis in Myxofibrosarcoma remain to be determined. Herein, utilizing gene expression profiling data and clinical follow-up data of Myxofibrosarcoma cases in three independent cohorts with a total of 128 Myxofibrosarcoma samples from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, we constructed an easy-to-use web tool, named Online consensus Survival analysis for Myxofibrosarcoma (OSmfs) to analyze the prognostic value of certain genes. Through retrieving the database, users generate a Kaplan–Meier plot with log-rank test and hazard ratio (HR) to assess prognostic-related genes or discover novel Myxofibrosarcoma prognostic biomarkers. The effectiveness and availability of OSmfs were validated using genes in ever reports predicting the prognosis of Myxofibrosarcoma patients. Furthermore, utilizing the cox analysis data and transcriptome data establishing OSmfs, seven genes were selected and considered as more potentially prognostic biomarkers through overlapping and ROC analysis. In conclusion, OSmfs is a promising web tool to evaluate the prognostic potency and reliability of genes in Myxofibrosarcoma, which may significantly contribute to the enrichment of novelly potential prognostic biomarkers and therapeutic targets for Myxofibrosarcoma.

A clinicopathologic examination of myxofibrosarcoma. Do surgical margins significantly affect local recurrence rates in this infiltrative sarcoma subtype?

BACKGROUND AND OBJECTIVES

Myxofibrosarcoma (MFS) is an aggressive soft tissue tumor with an unpredictable recurrence pattern. We sought to (a) determine whether margin status in MFS is correlated to rates of local recurrence (LR) and (b) identify demographic and treatment variables associated with disease-related outcomes in this population.

METHODS

This retrospective study identified 42 surgically treated patients with MFS over 10 years at a single institution. Patient demographics, tumor characteristics, intraoperative variables, and disease-related outcomes were recorded.

RESULTS

Thirty-three (83%) patients had negative surgical margins and seven (18%) had positive margins. Four of 32 patients (13%) with negative margins developed subsequent LR compared to six of seven (86%) patients with positive margins (p < .001). Three patients (75%) with metastatic disease were deceased at the end of the study, while five (15%) without metastasis were deceased (p = .024).

CONCLUSIONS

Positive margin procedures for MFS were associated with LR. However, negative surgical margins demonstrated a relatively high rate of LR compared to other soft tissue sarcoma subtypes. Furthermore, though MFS tends to locally recur and have a propensity for distant metastasis, patients are observed to have a higher probability of death from other causes.

Establishment and characterization of NCC-MFS2-C1: a novel patient-derived cancer cell line of myxofibrosarcoma

Myxofibrosarcoma (MFS) is among the most aggressive and complex sarcoma types that require novel therapeutic approaches for improved clinical outcomes. MFS displays highly complex karyotypes, and frequent alterations in p53 signaling and cell cycle checkpoint genes as well as loss-of-function mutations in NF1 and PTEN have been reported. The effects of radiotherapy and chemotherapy on MFS are limited, and complete surgical resection is the only curative treatment. Thus, the development of novel therapeutic strategies for MFS has long been long desired for MFS. Patient-derived cell lines are an essential tool for basic and translational research in oncology. However, public cell banks provide only a limited number of MFS cell lines. In this study, we aimed to develop a novel patient-derived MFS cell line, which was established from the primary tumor tissue of a 71-year-old male patient with MFS and was named NCC-MFS2-C1. A single-nucleotide polymorphism assay revealed that NCC-MFS2-C1 cells exhibited gain and loss of genetic loci. NCC-MFS2-C1 cells were maintained as a monolayer culture for over 24 passages for 10 months. The cells exhibited spindle-like morphology, continuous growth, and capacity for spheroid formation and invasion. Screening of 213 anticancer agents revealed that bortezomib, gemcitabine, romidepsin, and topotecan at low concentrations inhibited the proliferation of NCC-MFS2-C1 cells. In conclusion, we established a novel MFS cell line, NCC-MFS2-C1, which can be used for studying the molecular mechanisms underlying tumor development and for the in vitro screening of anti-cancer drugs.

Planned combined onco-plastic (COP) surgical approach improves oncologic outcomes in soft tissue sarcomas

BACKGROUND

Combined modality of radiotherapy and surgery is the standard of treatment of soft tissue sarcomas (STS). The goal of this study was to assess whether a Combined Onco-Plastic (COP) surgical approach in the setting of neo-adjuvant radiotherapy can improve the oncologic outcomes of STS and reduce the rate of wound complications.

METHODS

We performed a retrospective review of all patients with STS treated at a single sarcoma centre (St Vincent's Hospital, Melbourne) between 2007 and 2018. Patients were stratified into two groups based on whether they have received the COP approach or were closed primarily by the orthopaedic surgeon. We analysed oncological outcomes and rate of wound complications.

RESULTS

A total of 546 patients with comparable demographics and tumor characteristics were included. The COP approach was performed in 75.6% of the patients. Wide margins were obtained in 97.4% of the cases, and this was significantly higher in the COP group (p < 0.001). The cumulative rate of local recurrence was 4.9%, with a 52% risk reduction in the COP approach, although this reduction was not significant (HR = 0.48; 95% CI 0.21-1.06; p = 0.070). The COP approach had better disease free survival (DFS) (aHR 1.86, 95% CI 1.45-2.37; p < 0.001) and Overall survival (risk of death aHR 0.49; 95% CI 0.30-0.79; p = 0.004). The overall wound complication rate was 18.6% with no difference between the two groups.

CONCLUSION

A planned collaboration between the orthopaedic oncologist and the plastic surgeon is beneficial in the treatment of STS after neo-adjuvant radiotherapy, allowing remarkably good oncological outcomes and a low rate of wound complications.

Complete remission of a case of high-grade myxofibrosarcoma with lung metastases after modified MAID regimen chemotherapy

The role of chemotherapy in the treatment of myxofibrosarcoma is unclear. There are no randomized clinical trials evaluating the therapeutic effect of chemotherapy on myxofibrosarcoma. We report, to the best of our knowledge, the first case of myxofibrosarcoma successfully treated with mesna, pirarubicin, ifosfamide and dacarbazine (modified MAID) regimen. The patient achieved complete remission evaluated according to Response Evaluation Criteria in Solid Tumours (RECIST).

5-Aminolevulinic acid tumor paint and photodynamic therapy for myxofibrosarcoma: an in vitro study

Background

5-Aminolevulinic acid (5-ALA), a fluorescent contrast agent, has been used for tumor paint and photodynamic therapy (PDT) for various tumors, but its use with soft tissue sarcomas is not well documented. Myxofibrosarcoma, a subtype of soft tissue sarcoma with a high local recurrence rate, may benefit from similar types of treatment. The purpose of this study was to analyze the effects of 5-ALA tumor paint and PDT on a myxofibrosarcoma cell line.

Methods

Tumor paint was assessed by exposing micromass pellets of human adipose-derived stromal (ADS) cells or myxofibrosarcoma (MUG-Myx1) cells to 5-ALA. Cell pellets were then visualized using a microscope at established excitation and emission wavelengths. Corrected total cell fluorescence was calculated per accepted protocols. Photodynamic therapy was similarly assessed by exposing ADS and MUG-Myx1 cells to 5-ALA, with subsequent analysis via flow cytometry and real-time confocal microscopy.

Results

The use of 5-ALA tumor paint led to a selective fluorescence in MUG-Myx1 cells. Findings were confirmed by flow cytometry. Interestingly, flow cytometry results showed progressive selective cell death with increasing 5-ALA exposure as a result of the PDT effect. PDT was further confirmed using confocal microscopy, which revealed progressive cellular bubble formation consistent with advancing stages of cell death—a finding that was not seen in control ADS cells.

Conclusions

5-ALA tumor paint and PDT were successfully used on a human myxofibrosarcoma cell line (MUG-Myx1). Results from this study showed both selective fluorescent tagging and selective cytotoxicity of 5-ALA toward malignant myxofibrosarcoma cells, while sparing benign adipose control cells. This finding was further confirmed in a dramatic time-lapse video, visually confirming active, targeted cell death. 5-ALA’s two-pronged application of selective tumor identification and cytotoxicity may transform surgical and medical approaches for treating soft tissue sarcomas.

Immunohistochemical selection of biomarkers for tumor-targeted image-guided surgery of myxofibrosarcoma

Myxofibrosarcoma(MFS) is the most common soft tissue sarcoma(STS) in elderly patients. Surgical resection remains the main treatment modality but tumor borders can be difficult to delineate with conventional clinical methods. Incomplete resections are a common problem and local recurrence remains a clinical issue. A technique that has shown great potential in improving surgical treatment of solid tumors is tumor targeted imaging and image-guided surgery with near-infrared fluorescence. To facilitate this technique, it is essential to identify a biomarker that is highly and homogenously expressed on tumor cells, while being absent on healthy non-malignant tissue. The purpose of this study was to identify suitable molecular targets for tumor-targeted imaging of myxofibrosarcoma. Ten potential molecular targets for tumor targeted imaging were investigated with immunohistochemical analysis in myxofibrosarcoma tissue (n = 34). Results were quantified according to the immunoreactive score(IRS). Moderate expression rates were found for uPAR, PDGFRa and EMA/MUC1. High expression rates of VEGF and TEM1 were seen. Strong expression was most common for TEM1 (88.2%). These results confirms that TEM1 is a suitable target for tumor-targeted imaging of myxofibrosarcoma. Keywords Image-guided surgery; Immunohistochemistry; Molecular imaging; Myxofibrosarcoma; Soft tissue sarcoma; Tumor endothelial marker 1(TEM1), Vascular endothelial growth factor (VEGF).

Extremity Soft Tissue Sarcoma: Role of Local Control

OPINION STATEMENT

For localized extremity soft tissue sarcoma (eSTS), treatment is individualized and each patient needs to be evaluated by a multidisciplinary team at a referral sarcoma center specialized in the care of sarcoma. For a majority of patients, treatment for eSTS involves limb-salvage surgery, with or without the addition of radiation therapy. Surgery should only be performed by surgeons specifically fellowship trained in the resection of eSTS. Surgery alone may be considered for small, low-grade, and superficial tumors as long a wide (≥ 2 cm) margin can be achieved. In cases where a less than wide negative margin can be achieved, radiation therapy should be utilized to facilitate a planned close margin resection to preserve critical structures (such as nerves, blood vessels, and bone) without a significant impact on oncologic outcomes. Soft tissue sarcomas are rare, and as such patients often present following an inadvertent excision. In these situations, we recommend preoperative radiation and wide tumor bed re-excision, as rates of residual tumor can be high in this scenario. While there is large amount of evidence to support the use of radiotherapy to enhance local tumor control, the evidence to support the use of chemotherapy to enhance local tumor control is lacking, and as such cannot be recommended for all patients.

Early Lymph Node Metastasis May Predict Poor Prognosis in Soft Tissue Sarcoma

Background

Lymph node metastasis (LNM) is a relatively rare event in soft tissue sarcoma. An association between the timing of LNM detection and patient prognosis is presently unknown.

Patients and Methods

We retrospectively analyzed the clinicopathological features of 33 patients with LNM between 2001 and 2015. Analysis of the timing of LNM diagnosis was grouped according to patients presenting LNM in either <8 months (the median time from primary tumor diagnosis to LNM) or ≥8 months after primary tumor diagnosis.

Results

A relationship between the primary tumor size and the timing of the LNM was not significantly found (Rs = 0.0088, p=0.96). Sixteen patients had an LNM detection duration of <8 months, and 17 patients had a duration of ≥8 months. The 5-year survival for patients with an LNM detection duration of <8 months and ≥8 months was 19% and 71%, respectively (p=0.0016). There were 19 patients with pulmonary metastases. Among them, there were 13 patients with a duration of primary tumor diagnosis to LNM of <8 months and 6 with a duration of ≥8 months (p=0.01).

Conclusion

Early LNM (<8 months) may predict poor prognosis in soft tissue sarcoma.

Upper extremity myxofibrosarcoma mimicking an erosive inflammatory arthritis: a case report

Myxofibrosarcoma is a malignant fibroblastic soft tissue neoplasm containing a variable amount of myxoid stroma that commonly presents as a slow-growing mass in elderly patients. The neoplasm may be superficial or deep to the muscle fascia and characteristically has an infiltrative growth pattern with a dominant or multinodular mass. We describe an unusual case of high-grade myxofibrosarcoma of the wrist and forearm that infiltrated the muscles, tendons, and wrist joint, causing bone erosions. The tumor was mistakenly diagnosed as synovitis and a chronic, erosive, inflammatory process. The diffuse nature, absence of a dominant mass, and radiographic appearance complicated the diagnosis. Although neoplasms of the synovial spaces are rare, this case demonstrates that tumors with a highly infiltrative growth pattern can mimic inflammatory synovitis and that neoplasms should be considered in the differential diagnosis when clinical and laboratory features are discordant with the imaging appearance.

High Recurrence Rate of Myxofibrosarcoma: The Effect of Radiotherapy Is Not Clear

Background

Myxofibrosarcoma (MFS) is one of the more common types of soft-tissue sarcoma (STS) in patients over 60 years of age. Local recurrence (LR) rates have been reported to be higher compared to other STS types.

Patients and Methods

Using a population-based series from the southern Sweden health care region, 56 consecutive patients with MFS and localized disease at diagnosis were analyzed with respect to LR and distant metastases after surgery ± adjuvant treatment.

Results

The overall local recurrence (n = 15) and metastasis (n = 13) rates were 27% and 21%, respectively; 6 patients had both. Surgical margin was the only statistically significant prognostic factor for LR. Patients operated with a marginal margin had an HR of 4.5 (CI 1.3–15.1, p=0.02) and those operated with an intralesional margin 9.4 (CI 2.0–43.5, p=0.004) compared to those operated with a wide surgical margin. There was no difference in the LR rate depending on radiotherapy or not, although the latter group had smaller and more superficial tumors. 23 patients received radiotherapy, 9 of whom developed LR, all within the irradiated field. A tumor size >5 cm and intralesional surgical margin were shown to be risk factors for distant metastases.

Conclusions

The rate of LR for patients with myxofibrosarcoma was high. The impact of RT on local tumor control was unclear. The surgical margin was important for both local and distant tumor control. Large tumor size was a risk factor for distant metastasis.

Predictors of Local Recurrence in Patients With Myxofibrosarcoma

OBJECTIVES

Myxofibrosarcoma (MFS) is reported to have a higher risk of local recurrence (LR) following definitive surgical excision relative to other soft tissue sarcomas. We reviewed our clinical experience treating MFS to investigate predictors of LR.

MATERIALS AND METHODS

We retrospectively reviewed treatment outcomes for MFS patients treated at our institution between 1999 and 2015. A total of 52 patients were identified. Median age was 65 years (range, 21 to 86 y). Site of disease was: upper extremity (27%), lower extremity (46%), trunk (15%), pelvic (8%), and head and neck (4%). Patients had low, intermediate, high-grade, and unknown grade in: 23%, 8%, 67%, and 2% of tumors, respectively. Tumors were categorized as ≤5 cm (35%), >5 cm (56%), or unknown size (9%). In total, 71% received radiotherapy: 19% preoperative, 50% postoperative, and 2% both. All patients underwent surgery. Margins were negative in 71%, close/positive in 21%, and unknown in 8%. In total, 27% of patients received chemotherapy. Univariate Cox regression analysis was utilized to determine associations between clinical and treatment factors with LR.

RESULTS

Median follow-up time was 2.9 years (range, 0.4 to 14.3 y). The 3-year actuarial LR, distant metastasis, and overall survival were: 31%, 15%, and 87%, respectively. Predictors of LR were patient age greater than or equal to the median of 65 years (hazard ratio, 13.46, 95% confidence interval, 1.71-106.18, P=0.013), and having close/positive tumor margins (hazard ratio, 3.4, 95% confidence interval, 1-11.53, P=0.049).

CONCLUSIONS

In this institutional series of MFS older age and positive/close margins were significantly associated with a higher risk of LR.

Significance of HIFU in local unresectable recurrence of soft tissue sarcoma, a single-center, respective, case series in China

PURPOSE

Multimodality treatment of soft tissue sarcoma(STS) by expert teams reportedly affords a tremendous improvement in outcome of patients. Despite advances, treatment of local unresectable recurrence remains difficult and is not standardized. We performed this retrospective study in order to assess the efficacy and safety of high-intensity focused ultrasound (HIFU) ablation in treating STS patients with local unresectable recurrence.

METHODS

Thirty-six STS patients with local unresectable recurrence from January 2015 to December 2016 were recruited according to the inclusion criteria. Pain rating, response rate, disease control rate, local disease progression-free survival(LPFS), progression-free survival (PFS) and overall survival(OS) were used to evaluate efficacy of HIFU treatment.

RESULTS

HIFU resulted in a significant relief in pain rating, without severe side effects. According to magnetic resonance imaging(MRI), three months after HIFU treatment, response rate was 47.3% and the local disease control rate was 80.6%. Twelve months post HIFU treatment, response rate was 38.9% and the local disease control rate was 55.6%. The median LPFS, PFS and OS time for 36 patients was 13 months, 10 months and 20 months respectively.

CONCLUSION

HIFU is a tolerated treatment modality with promising activity and safety in STS patients with local unresectable recurrence.

Canine myxosarcomas, a retrospective analysis of 32 dogs (2003-2018)

Background

Myxosarcomas are known to be classified as soft tissue sarcomas. However, there is limited clinical characterization pertaining specifically to canine cutaneous myxosarcomas in the literature. The objective of this study is to evaluate the local recurrence rate, metastatic rate and prognosis of canine myxosarcoma.

Results

A total of 32 dogs diagnosed with myxosarcoma via histopathology were included in this retrospective study. All dogs had surgical resection. No adjunct treatments were performed in 9 dogs, while 22 dogs also received either radiation therapy or chemotherapy, or a combination of both. One dog received only NSAID after surgery. Overall median survival time (MST) was 730 days (range 20–2345 days). The MST of dogs with a tumor mitotic count < 10/10 HPF was 1393 days (range 20–2345 days). The dogs with a tumor mitotic count of 10 or greater/10 HPF had a MST of 433 days (range 169–831 days). There was no significant difference of MST among different treatment modalities. Local recurrence was noted in 13 cases (40.6%) and the median time to recurrence was 115.5 days (range 50–1610 days). The median time to local recurrence in dogs with mitotic count of < 10/10 HPF was 339 days (range 68–1610 days) and in dogs with mitotic count of 10 or greater/10 HPF was 119 days (range 50–378). Metastasis to local lymph node or lung was noted in 8 cases (25%) with median time to metastasis of 158.5 days (range 0–643 days).

Conclusions

Based on the results of this retrospective study, myxosarcoma may have a higher local recurrence rate and risk of metastasis to the local lymph nodes compared to other soft tissue sarcomas.