Prognostic significance of microscopic tumor extension in local recurrence of myxofibrosarcoma and undifferentiated pleomorphic sarcoma

A Detailed Examination of Retroperitoneal Undifferentiated Pleomorphic Sarcoma: A Case Report and Review of the Existing Literature

This detailed review focuses on retroperitoneal undifferentiated pleomorphic sarcoma (UPS), a particularly aggressive soft-tissue sarcoma that poses unique diagnostic and therapeutic challenges due to its rarity and complex presentation. By documenting a new case of retroperitoneal UPS and conducting a comprehensive review of all known cases, this article aims to expand the existing body of knowledge on the epidemiology, molecular pathogenesis, and treatment strategies associated with this rare disease. The complexity of diagnosing UPS is emphasized given that it rarely occurs in the retroperitoneal space and its histological and molecular complexity often complicates its recognition. This review highlights the need for specialized diagnostic approaches, including advanced imaging techniques and histopathological studies, to accurately diagnose and stage the disease. In terms of treatment, this paper advocates a multidisciplinary approach that combines surgery, radiotherapy and chemotherapy and tailors it to individual patients to optimize treatment outcomes. This review highlights case studies that illustrate the effectiveness of surgical intervention in the treatment of these tumors and emphasize the importance of achieving clear surgical margins to prevent recurrence. Furthermore, this review discusses the potential of new molecular targets and the need for innovative therapies that could bring new hope to patients affected by this challenging sarcoma.

Clear surgical margins as a prognostic indicator for disease recurrence, with no impact on survival rates in patients with myxofibrosarcoma

Myxofibrosarcoma presents an infiltrating growth pattern that results in a high tendency for local recurrence. Clear margin resection is challenging because of microscopic infiltration. The purpose of the present study was to analyze the overall and disease-free survival rates of patients with myxofibrosarcoma and the prognostic factors that determine both survival and disease recurrence. Among the 111 patients included in our study, the 5-year overall survival rate was 65.5%. An age of more than 65 years (hazard ratio [HR] 1.9 [95% confidence interval (CI) 1.4-5.6]; p < 0.001), a tumor size of more than 5 cm (HR 2.8 [95% CI 0.9-8.1]; p = 0.049) and the G3 tumor grade (HR 14.1 [95% CI 2.1-105.0]; p < 0.001) negatively affected overall survival. The 5-year recurrence-free survival rate was 49.4%. R1/R2-type resection (HR 2.4 [95% CI 1.0-5.6]; p = 0.048) had a detrimental effect on tumor recurrence. Clear margins had a positive impact on recurrence-free survival, but did not significantly affect overall patient survival, suggesting that other factors may play a more significant role in determining patient outcomes. A surgical margin of 2 mm was not sufficient to significantly influence the incidence of recurrence. Consequently, a wider surgical margin may be necessary to reduce the risk of myxofibrosarcoma recurrence.

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.

Multiple Flap Transfer for Multiple Local Recurrence of Soft Tissue Sarcoma

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

Retroperitoneal undifferentiated pleomorphic sarcoma with total nephrectomy: a case report and literature review

Background

Undifferentiated pleomorphic sarcoma (UPS) is a highly malignant soft tissue sarcoma with a poor prognosis and no clear effective clinical means for treatment, and there has been no significant progress in research within this field in recent years. This study aimed to investigate the epidemiology, etiology, clinical features, diagnostic modalities, various treatment modalities, and prognosis of retroperitoneal undifferentiated pleomorphic sarcoma and to contribute to the clinical management of this type of disease. In this study, we report a case of undifferentiated pleomorphic sarcoma with a primary origin in the retroperitoneum. Undifferentiated pleomorphic sarcoma occurring in the retroperitoneum is rarely reported.

Case description

A 59-year-old man with abdominal distension and pain for 4 months presented to our hospital after the failure of conservative treatment. A 9.6 cm by 7.4 cm mass in the left retroperitoneum was found on a CT scan of the whole abdomen with three degrees of enhancement. After surgical treatment, the tumor and the left kidney were completely removed, and pathological examination and genetic sequencing showed an apparent undifferentiated pleomorphic sarcoma. The patient subsequently declined follow-up treatment and is currently alive and well.

Conclusions

At the current level of clinical technology, the treatment of undifferentiated pleomorphic sarcoma is still in the exploratory stage, and the scarcity of clinical cases of this disease may have hindered the acquisition of clinical trials and research data for this disease. At present, the first choice of treatment for undifferentiated pleomorphic sarcoma is still radical resection. In the existing clinical studies, there are no strong data to support the effect of preoperative neoadjuvant chemoradiotherapy and adjuvant chemoradiotherapy in clinical practice. Similar to other diseases, the use of radiotherapy and chemotherapy before and after surgery may be a potential treatment for this disease in the future. Targeted therapy for this disease still needs further exploration, and we need more reports on related diseases to promote future treatment and research on this disease.

Percutaneous biopsy of musculoskeletal tumors and the potential for needle tract seeding: technical considerations, current controversies, and outcomes

Multidisciplinary communication and planning between the musculoskeletal radiologist and orthopedic oncologist are essential for proper biopsy planning when a primary musculoskeletal malignancy is suspected. Image-guided percutaneous biopsy allows for real-time visualization of the biopsy needle and surrounding structures, combining high diagnostic accuracy with safety and cost-effectiveness. However, determining a surgically optimal biopsy trajectory for a mass can be technically challenging due to critical surrounding anatomy or challenging needle approach angles. Inappropriately placed biopsies can have serious repercussions on patient function and oncological survival. The potential for needle tract seeding and local recurrence after biopsy of sarcoma has been central to the debate regarding the need for excision of the biopsy tract. This multidisciplinary review highlights current controversies in the field, including the issue of core needle biopsy tracts and their excision, technical considerations and advances in image-guidance in the setting of challenging biopsies, advances in histopathological diagnostics with implications for targeted therapy in sarcoma, as well as surgical and oncological outcomes after needle tract biopsy.

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.

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.

Multiple recurrent myxofibrosarcoma of the orbit: case report and review of the literature

Background

Although myxofibrosarcoma (MFS) is the most common mesenchymal tumor, occurrence in the orbit is extremely rare. A characteristic clinical feature of MFS is its propensity for local recurrence (LR). Still, none of published literature has described the entire clinical course of multiple recurrences of MFS in the orbit. Here we present an unusual case in which a patient with multiple recurrences of MFS in the orbit followed-up for 5 years. We describe its clinical-pathological correlation, treatment, and prognosis.

Case presentation

A 70-year-old woman sought treatment for a year history of right upper eyelid swelling in May 2014. Since then, she underwent three surgical procedures in the right orbit in the same region (in 2014, 2016, and 2017). The pathology analysis of the three surgical tissue samples was consistent with myxofibrosarcoma, characterized by spindle-shaped cells and variably myxoid stroma. In the 2 years follow-up after the third surgery, there was no evidence of tumor recurrence.

Conclusion

Myxofibrosarcoma of the orbit is extremely rare. Since few reports are available in the literature, the diagnosis and management of the orbit myxofibrosarcoma is still a challenge to ophthalmologists. Histopathology is highly valuable in the diagnosis. As a clinical characteristic, the lesions have a high risk of local recurrence; therefore, aggressive resection and careful postoperative follow-up are paramount.

Pathogenic and Targetable Genetic Alterations in Resected Recurrent Undifferentiated Pleomorphic Sarcomas Identified by Targeted Next-generation Sequencing

BACKGROUND/AIM

Undifferentiated pleomorphic sarcomas (UPSs) are difficult to treat, with a high recurrence rate. However, the genetic and molecular characterization of recurrent UPS has not been identified.

PATIENTS AND METHODS

In this study, we investigated the pathogenic and targetable genetic alterations in 16 paired locally pre-recurrent and post-recurrent UPS cases by targeted next-generation sequencing (466 genes).

RESULTS

Sequence variations were most frequently found in TP53 (66%), ATRX (34%), and RB1 (28%). In addition, for the first time, recurrent IL7R gene amplification (19%) and KMT2C gene mutation (16%) were detected in UPS. Interestingly, genetic alterations varied with tumor relapse. Importantly, targetable driver variants were found in recurrent UPS. Mutated genes were correlated with the cell cycle, PI3K/mTOR and RAS/MAPK signaling pathways. TMB was also found to be increased after tumor recurrence (4.6 vs. 7.5 mutations/MB, p=0.0343).

CONCLUSION

Routine use of targeted next-generation sequencing for recurrent UPS can facilitate timely therapeutic decision-making.