Diagnosis and treatment of soft-tissue sarcomas of the extremities and trunk

Molecular Imaging in Soft-tissue Sarcoma: Evolving Role of FDG PET

Soft tissue sarcomas are a rare and heterogenous group of tumors that account for 2% of all cancer-related deaths. Molecular imaging with FDG PET can offer valuable metabolic information to help inform clinical management of soft tissue sarcomas that is unique and complementary to conventional diagnostic imaging techniques. FDG PET imaging often correlates with tumor grade, can help guide biopsy, and frequently detects additional sites of disease compared to conventional imaging in patients being considered for definitive or salvage therapy. Traditional size-based evaluation of treatment response is often inadequate in soft tissue sarcoma and changes in metabolic activity can add significant value to interim and end of treatment imaging for high-grade sarcomas. FDG PET can be used for detection of recurrence or malignant transformation and thus play a vital role in surveillance. This article reviews the evolving role of FDG PET in initial diagnosis, staging, treatment response assessment, and restaging. Further studies on the use of FDG PET in soft sarcoma are needed, particularly for rare histopathologic subtypes.

Radiotherapy versus limb-sparing surgery alone in low-grade soft-tissue sarcoma of the extremity and trunk wall: a systematic review and meta-analysis

Current guidelines recommend the use of radiotherapy in the management of intermediate and high-grade soft-tissue sarcoma of the extremity and trunk wall. Its use in low-grade sarcoma is less clear. To date there have been no pooled data analyses regarding its role in this context. Its use is not without complications and therefore must be justified. We aim to assess the oncological impact of radiotherapy versus limb-sparing surgery alone in this subset of sarcoma. Medline, EMBASE and Cochrane's databases were searched from 1982 to present. Studies on or having a subgroup analysis of low-grade soft tissue sarcoma, with a radiotherapy and a surgery only arm were included. Outcomes included local recurrence and overall survival. Patients were at least 16 years of age with primary de-novo sarcoma who had not undergone prior resection or treatment. Those undergoing concomitant therapy were excluded. Data extraction was performed independently by two reviewers. Results were pooled using a random-effects model and presented as a forest plot. Primary outcome measures included local recurrence and overall survival. Eleven unique studies were included, consisting of two RCTs and nine non-randomized studies. Overall, there were 12 799 patients. Four studies were included in meta-analysis and the overall pooled effect showed a limited role of radiotherapy in overall survival outcomes when compared to limb-sparing surgery alone HR 1.00 [0.83-1.20] P = 0.41. Descriptive analysis suggests there is limited role of radiotherapy in improving local recurrence outcomes. This study suggests there is limited role for radiotherapy versus limb-sparing surgery alone in low-grade soft-tissue sarcoma. These findings strongly suggest there is lack of high-quality data and that further research must be undertaken prior to forming any strong conclusions regarding the management of low-grade soft-tissue sarcoma. Demonstrating a role for radiotherapy may help improve the quality of excisional margins and thus potentiate limb-sparing surgery.

The Effect of chemo- and radiotherapy on tumor necrosis in soft tissue sarcoma- does it influence prognosis?

BACKGROUND

Soft tissue sarcomas (STSs) are a heterogeneous group of tumors. Wide surgical resection is standard, often combined with neoadjuvant chemotherapy, radiotherapy, or both. Studies have shown the predictive value of tumor necrosis in bone sarcoma (BS); however, the role of necrosis in STS after neoadjuvant therapies is still unclear. This study aimed to investigate the role of chemo- and radiotherapy in the formation of tumor necrosis and to evaluate the influence of tumor necrosis on overall survival and local recurrence-free survival. Data from BS patients and patients who did not receive neoadjuvant therapy were compared.

METHODS

A total of 779 patients with STS or BS were treated surgically. In all patients, tumor-specific factors such as type, size, or grading and the type of adjuvant therapy were documented. Local recurrence (LR), the diagnosis of metastatic disease, and survival during follow-up were evaluated.

RESULTS

A total of 565 patients with STS and 214 with BS were investigated. In STS, 24.1% G1 lesions, 34.1% G2 lesions, and 41.8% G3 lesions were observed. Two hundred twenty-four of the patients with STS and neoadjuvant therapy had either radiotherapy (RTx) (n = 80), chemotherapy (CTx) (n = 93), or both (n = 51). Three hundred forty-one had no neoadjuvant therapy at all. In STS, tumor necrosis after neoadjuvant treatment was significantly higher (53.5%) than in patients without neoadjuvant therapy (15.7%) (p < 0.001). Patients with combined neoadjuvant chemo-/radiotherapy had substantially higher tumor necrosis than those with radiotherapy alone (p = 0.032). There was no difference in tumor necrosis in patients with combined chemo-/radiotherapy and chemotherapy alone (p = 0.4). The mean overall survival for patients with STS was 34.7 months. Tumor necrosis did not influence survival in a subgroup of G2/3 patients. In STS with no neoadjuvant therapy and grading of G2/3, the correlation between necrosis and overall survival was significant (p = 0.0248). There was no significant correlation between local recurrence (LR) and necrosis.

CONCLUSION

STS shows a broad spectrum of necrosis even without neoadjuvant chemo- or radiotherapy. After CTx or/and RTx necrosis is enhanced and is significantly pronounced with a combination of both. There is a trend toward higher necrosis with CTx than with RTx. Grading substantially influences the necrosis rate, but necrosis in soft-tissue sarcoma following neoadjuvant therapy does not correlate with better survival or a lower local recurrence rate, as in bone sarcomas.

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.

Do Patients Treated With an Unplanned Resection for Small Superficial Soft Tissue Sarcomas Have Worse Long-term Survival Than Those Initially Treated With an Oncologic Resection?

BACKGROUND

Histologic grade, size, and depth are well-known prognostic factors in soft tissue sarcomas (STS). Small (< 5 cm) and superficial STS generally have an excellent prognosis when treated with appropriate surgery. However, they are often misdiagnosed and mistreated. We reported that in midterm follow-up (5 to 7 years), patients with unplanned resections of tumors with positive margins who immediately underwent a reoperation with margin-widening re-resection and postoperative radiotherapy had survival comparable to that of patients who were initially treated correctly. In that article, we included STS larger than 5 cm, deep STS, and individuals with local recurrence. However, we wanted to evaluate the impact of unplanned resection on the survival of patients who had STS with the best prognosis, small and superficial STS, with two groups that were as homogeneous as possible.

QUESTION/PURPOSE

Do patients with small and superficial STS who underwent an unplanned resection have worse prognosis in the long term than those who were initially treated correctly?

METHODS

We exclusively evaluated patients with small (< 5 cm) and superficial (to the deep fascia) STS. We systematically excluded deep STS. Among this subset, we identified 93 patients with superficial STS. We excluded patients with local relapse, metastatic disease, superficial STS of the head or neck, those with insufficient clinical or dosimetric information, and patients with follow-up of less than 2 years. Furthermore, our focus on investigating the most benign and homogeneous STS prompted us to exclude patients with superficial tumors greater than or equal to 5 cm. This selection was driven by the presumed better prognosis associated with smaller tumors, inevitably leading to a smaller pool of patients for direct comparison with patients who had unplanned resections. The initial expectation was to observe similar survival outcomes between cohorts. Between 1990 and 2019, a total of 17 patients underwent surgical treatment at our private, medium-size center. Of those, 29% (5 patients) were lost to follow-up before 2 years without meeting a study endpoint (relapse, metastasis or revision, reoperation, or death), leaving a total of 71% (12 patients) of the original group who had either follow-up of at least 2 years or who met a study endpoint before that minimum surveillance duration. They were treated with surgery alone. During that same period, another 51 patients were referred to us after undergoing an unplanned resection of a lesion that subsequently was determined to be a soft tissue malignancy. Of those, 18% (9 patients) were lost to follow-up before 2 years without meeting a study endpoint, leaving 82% (42 patients) of the original group who had either follow-up of at least 2 years or who met a study endpoint before that minimum surveillance duration. They were treated with re-excision and postoperative radiotherapy. Patients with unplanned resections had an older mean age (51± 5 versus 44 ± 7 years; p = 0.1) and a higher proportion of female patients (58% versus 38%; p = 0.07), but the groups did not differ in terms of largest diameter, histologic type, or tumor location. However, patients with planned resections had a higher proportion of high-grade STS (75% versus 55%; p = 0.07). No metastases were present in either group at diagnosis. We performed a univariate analysis of the groups. We could not perform a multivariate analysis because of the small sample. We compared the groups in terms of local recurrence and all-cause mortality using the Kaplan-Meier survivorship estimator.

RESULTS

According to the Kaplan-Meier survivorship estimator, survivorship free from local recurrence at a mean of 20 years of follow-up was better in the planned resection group than in the unplanned resection group (92% [95% CI 63% to 100%] versus 69% [95% CI 54% to 81%]; p = 0.04). Furthermore, overall survivorship at 5 years was higher in the planned resection group than in the unplanned resection group (100% [95% CI 72% to 100%] versus 70% [95% CI 54% to 81%]; p = 0.04). Similarly, the planned resection group exhibited superior survivorship at 20 years of follow-up (100% [95% CI 72% to 100%] versus 62% [95% CI 47% to 75%]; p = 0.01). Metastatic disease was absent in the planned resection group, while it occurred in 12 patients in the unplanned resection group (28% [95% CI 17% to 44%]).

CONCLUSION

Unplanned resection for patients with small and superficial STS was associated with a decrease in overall survival in the long term, despite the use of postoperative radiotherapy. An unplanned resection may be an important prognostic factor. Nevertheless, larger and prospective studies are needed to validate our findings. Although small and superficial lumps are usually benign, nonsarcoma surgeons should be aware that some masses may be malignant, and if in doubt, MR imaging, a biopsy before excision, or consultation with or referral to a sarcoma center should be considered before removing the mass.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Thematic analysis of online discussion forums for soft tissue sarcomas

BACKGROUND AND OBJECTIVES

As there is an increasing reliance on the internet for medical information, patients diagnosed with rare diseases have turned to online community forums to share information about their diagnoses. These forums help patients to gather and share information about their experience with disease. Additionally, these platforms enable patients to build unique connections based on their shared experiences. The objective of this study was to review shared posts in online community forums by individuals with soft tissue sarcomas to better understand commonly discussed themes. This information may improve the physicians' understanding of patients' concerns and feelings at the time of diagnosis and treatment.

METHODS

We entered "sarcoma discussion forum" in search engines to identify internet discussion boards. Four major discussion forums were analyzed, and posts written between January 1, 2017 through May 1, 2022 addressing soft tissue sarcomas present in the upper and lower extremities were collected. Each post was analyzed by the two investigators in three steps (open coding, axial coding, and selective coding).

RESULTS

A total of 506 posts were included in the final analysis. We used twenty-seven axial codes and four selective codes. Emotional Aspects/Connecting with Others was the most common theme (77 % of posts) followed by Information Support: Treatment (38 % of posts), Information Support: Diagnosis (24 % of posts) and Information Support: Recovery (21 % of posts).

CONCLUSIONS

The most prevalent theme was centered on emotional aspects of these patients' journeys, highlighting the importance of providing resources to address emotional support for patients with soft tissue sarcoma and their families.

LEVEL IV

Qualitative research study.

Patients' Experiences of a Sarcoma Diagnosis: A Process Mapping Exercise of Diagnostic Pathways

Patients with sarcoma often report prolonged time to diagnosis, which is attributed to the rarity of sarcoma and the low awareness of pre-diagnostic signs and symptoms.

AIMS

To describe patients' experiences of pre-diagnostic signs/symptoms and pathways to diagnosis, including where help was sought, and the processes involved.

METHODS

Mixed methods involving quantitative, qualitative and inductive thematic analyses using novel process mapping of patient journey data, as reported by the patients. We examined the time from symptom onset to first professional presentation (patient interval, PI), first consultation to diagnostic biopsy, first consultation to diagnosis (diagnostic interval) and first presentation to diagnosis (total interval).

RESULTS

A total of 87 interviews were conducted over 5 months in 2017. Of these, 78 (40 males/38 females) were included. The sarcoma subtypes were bone (n = 21), soft tissue (n = 41), head and neck (n = 9) and gastro-intestinal (GIST; n = 7). Age at diagnosis was 13-24 (n = 7), 25-39 (n = 23), 40-64 (n = 34) and 65+ (n = 14) years. The median PI was 13 days (1-4971) and similar between sarcoma subtypes, with the exception of GIST (mPI = 2 days, (1-60). The longest mPI (31 days, range 4-762) was for those aged 13-24 years. The median diagnostic interval was 87.5 (range 0-5474 days). A total of 21 patients were misdiagnosed prior to diagnosis and symptoms were commonly attributed to lifestyle factors.

CONCLUSIONS

Prolonged times to diagnosis were experienced by the majority of patients in our sample. Further research into the evolution of pre-diagnostic sarcoma symptoms is required to inform awareness interventions.

Experience of a single center in the treatment of rare malignant peripheral nerve sheath tumors during the years 1991-2021

Malignant peripheral nerve sheath tumor (MPNST) is a rare sarcoma with a poor prognosis, as the aggressive types of this cancer tend to grow rapidly and metastasize frequently. MPNST is associated with neurofibromatosis type 1 gene mutation. The minority of cases arise secondary to radiation therapy or sporadically. The primary treatment for MPNST is early surgical resection of the tumor. The aim of this study was to retrospectively evaluate the outcome of the treatment of MPNST in Helsinki University Hospital from the years 1991 to 2021. Fourteen MPNST cases were evaluated in this study retrospectively. Descriptive statistical analysis was performed on the collected patient data. Marginal resection was completed in nine cases, wide margins were achieved in three cases, and in two cases the final histological examination of the specimen revealed intralesional removal. During the follow-up time of 36.7 ± 12.1 months, all patients who underwent wide margin resection were alive. One patient died 22 months after intralesional resection and six within 38.3 ± 30.9 months of marginal resection. Seventy-one percent of tumor surgeries resulted in Clavien-Dindo class 3b complications, reflecting the complexity of the surgeries. The aggressive nature of MPNST and the large size of these tumors requires extensive surgery, which can lead to complications. The prognosis of MPNST needs improvement.

Predicting pathological complete response of neoadjuvant radiotherapy and targeted therapy for soft tissue sarcoma by whole-tumor texture analysis of multisequence MRI imaging

OBJECTIVES

To construct effective prediction models for neoadjuvant radiotherapy (RT) and targeted therapy based on whole-tumor texture analysis of multisequence MRI for soft tissue sarcoma (STS) patients.

METHODS

Thirty patients with STS of the extremities or trunk from a prospective phase II trial were enrolled for this analysis. All patients underwent pre- and post-neoadjuvant RT MRI examinations from which whole-tumor texture features were extracted, including T₁-weighted with fat saturation and contrast enhancement (T₁FSGd), T₂-weighted with fat saturation (T₂FS), and diffusion-weighted imaging (DWI) sequences and their corresponding apparent diffusion coefficient (ADC) maps. According to the postoperative pathological results, the patients were divided into pathological complete response (pCR) and non-pCR (N-pCR) groups. pCR was defined as less than 5% of residual tumor cells by postoperative pathology. Delta features were defined as the percentage change in a texture feature from pre- to post-neoadjuvant RT MRI. After data reduction and feature selection, logistic regression was used to build prediction models. ROC analysis was performed to assess the diagnostic performance.

RESULTS

Five of 30 patients (16.7%) achieved pCR. The Delta_Model (AUC 0.92) had a better predictive ability than the Pre_Model (AUC 0.78) and Post_Model (AUC 0.76) and was better than AJCC staging (AUC 0.52) and RECIST 1.1 criteria (AUC 0.52). The Combined_Model (pre, post, and delta features) had the best predictive performance (AUC 0.95).

CONCLUSION

Whole-tumor texture analysis of multisequence MRI can well predict pCR status after neoadjuvant RT and targeted therapy in STS patients, with better performance than RECIST 1.1 and AJCC staging.

KEY POINTS

• MRI multisequence texture analysis could predict the efficacy of neoadjuvant RT and targeted therapy for STS patients. • Texture features showed incremental value beyond routine clinical factors. • The Combined_Model with features at multiple time points showed the best performance.

Issues of diagnostic search of soft tissue sarcoma

Relevance. Soft tissue sarcoma is a heterogeneous group of relatively rare types of tumors, which demonstrates a huge variety of anatomical localization and histopathological characteristics. The rarity of soft tissue sarcomas combined with a variety of subtypes, forms of growth, progression and frequency of relapses makes it difficult to study them, make a correct diagnosis and early referral of patients for specialized care.

The purpose of study. To analyze the problem of differential diagnosis of malignant and benign soft tissue neoplasms.

Materials and methods. In the course of the work, current literary sources of domestic and foreign authors on a given topic were analyzed.

Results. Since it is absolutely impossible to determine the clinical features of the presented sarcoma, soft tissue tumors showing any of the following signs are considered malignant until the opposite is proven: increasing in size, >5 cm, deeply located and/or painful. The greater the number of these clinical signs present, the higher the risk that the soft tissue tumor will turn out to be malignant; at the same time, an increase in size is the best individual indicator. It is worth noting that the absence of concomitant constitutional symptoms, such as fever, chills, night sweats or unintentional weight loss, should not reduce the doctor's suspicion of malignancy.

Conclusion. In order to avoid erroneous diagnoses, a standardized diagnostic approach should be followed, starting from the moment of collecting the patient's medical history, clinical examination and ending with the use of appropriate imaging methods and biopsy.

Issues of diagnostic search of soft tissue sarcoma

Relevance. Soft tissue sarcoma is a heterogeneous group of relatively rare types of tumors, which demonstrates a huge variety of anatomical localization and histopathological characteristics. The rarity of soft tissue sarcomas combined with a variety of subtypes, forms of growth, progression and frequency of relapses makes it difficult to study them, make a correct diagnosis and early referral of patients for specialized care.

The purpose of study. To analyze the problem of differential diagnosis of malignant and benign soft tissue neoplasms.

Materials and methods. In the course of the work, current literary sources of domestic and foreign authors on a given topic were analyzed.

Results. Since it is absolutely impossible to determine the clinical features of the presented sarcoma, soft tissue tumors showing any of the following signs are considered malignant until the opposite is proven: increasing in size, >5 cm, deeply located and/or painful. The greater the number of these clinical signs present, the higher the risk that the soft tissue tumor will turn out to be malignant; at the same time, an increase in size is the best individual indicator. It is worth noting that the absence of concomitant constitutional symptoms, such as fever, chills, night sweats or unintentional weight loss, should not reduce the doctor's suspicion of malignancy.

Conclusion. In order to avoid erroneous diagnoses, a standardized diagnostic approach should be followed, starting from the moment of collecting the patient's medical history, clinical examination and ending with the use of appropriate imaging methods and biopsy.

Sarcomas of the extremities and the pelvis: comparing local recurrence after incisional and after core-needle biopsy

Background

The degree of contamination of healthy tissue with tumor cells during a biopsy in bone or soft tissue sarcomas is clearly dependant on the type of biopsy. Some studies have confirmed a clinically relevant contamination of the biopsy tract after incisional biopsies, as opposed to core-needle biopsies. The aim of our prospective study was to evaluate the risk of local recurrence depending on the biopsy type in extremity and pelvis sarcomas.

Methods

We included 162 patients with a minimum follow-up of 6 months after wide resection of extremity sarcomas. All diagnostic and therapeutic procedures were performed at a single, dedicated sarcoma center. The excision of the biopsy tract after an incisional biopsy was performed as a standard with all tumor resections. All patients received their follow-up after the conclusion of therapy at our center by means of regional MRI studies and, at a minimum, CT of the thorax to rule out pulmonary metastatic disease. The aim of the study was the evaluation of the influence of the biopsy type and of several other clinical factors on the rate of local recurrence and on the time of local recurrence-free survival.

Results

One hundred sixty-two patients with bone or soft tissue tumors of the extremities and the pelvis underwent either an incisional or a core-needle biopsy of their tumor, with 70 sarcomas (43.2%) being located in the bone. 84.6% of all biopsies were performed as core-needle biopsies. The median follow-up time was 55.6 months, and 22 patients (13.6%) developed a local recurrence after a median time of 22.4 months. There were no significant differences between incisional and core-needle biopsy regarding the risk of local recurrence in our subgroup analysis with differentiation by kind of tissue, grading of the sarcoma, and perioperative multimodal therapy.

Conclusions

In a large and homogenous cohort of extremity and pelvic sarcomas, we did not find significant differences between the groups of incisional and core-needle biopsy regarding the risk of local recurrence. The excision of the biopsy tract after incisional biopsy in the context of the definitive tumor resection seems to be the decisive factor for this result.

Radiomics Analysis of Fat-Saturated T2-Weighted MRI Sequences for the Prediction of Prognosis in Soft Tissue Sarcoma of the Extremities and Trunk Treated With Neoadjuvant Radiotherapy

Purpose

To create a prognostic prediction radiomics model for soft tissue sarcoma (STS) of the extremities and trunk treated with neoadjuvant radiotherapy.

Methods

This study included 62 patients with STS of the extremities and trunk who underwent magnetic resonance imaging (MRI) before neoadjuvant radiotherapy. After tumour segmentation and preprocessing, 851 radiomics features were extracted. The radiomics score was constructed according to the least absolute shrinkage and selection operator (LASSO) method. Survival analysis (disease-free survival; DFS) was performed using the log-rank test and Cox’s proportional hazards regression model. The nomogram model was established based on the log-rank test and Cox regression model. Harrell’s concordance index (C-index), calibration curve and receiver operating characteristic (ROC) curve analysis were used to evaluate the prognostic factors. The clinical utility of the model was assessed by decision curve analysis (DCA).

Results

The univariate survival analysis showed that tumour location (p = 0.032), clinical stage (p = 0.022), tumour size (p = 0.005) and the radiomics score were correlated with DFS (p < 0.05). The multivariate analysis showed that tumour location, tumour size, and the radiomics score were independent prognostic factors for DFS (p < 0.05). The combined clinical-radiomics model based on the multivariate analysis showed the best predictive ability for DFS (C-index: 0.781; Area Under Curve: 0.791). DCA revealed that the use of the radiomics score-based nomogram was associated with better benefit gains relative to the prediction of 2-year DFS events than other models in the threshold probability range between 0.12 and 0.38.

Conclusion

The radiomics score from pretreatment MRI is an independent prognostic factor for DFS in patients with STS of the extremities and trunk. The radiomics score-based nomogram could improve prognostic stratification ability and thus contribute to individualized therapy for STS patients.

Ki-67 immunoexpression and radiological assessment of necrosis improves accuracy of conventional and modified core biopsy systems in predicting the final grade assigned to adult-soft tissue sarcomas. An international collaborative study

Based on the French Federation Nationale des Centers de Lutte Contre le Cancer (FNCLCC) grading system, this study assesses the accuracy of conventional and modified core biopsy (CB) systems in predicting the final grade (low vs high) assigned to the resected specimen. Substituting Ki-67 immunoexpression for mitotic count, and radiological for histological assessment of necrosis, we used two modified FNCLCC CB grading systems: (1) Ki-67 immunoexpression alone, and (2) Ki-67 plus radiological assessment of necrosis. We graded 199 soft tissue sarcomas (STS) from nine centers, and compared the results for the conventional (obtained from local histopathology reports) and modified CB systems with the final FNCLCC grading of the corresponding resected specimens. Due to insufficient sample quality or lack of available radiologic data, five cases were not evaluated for Ki67 or radiological assessment of necrosis. The conventional FNCLCC CB grading system accurately identified 109 of the 130 high-grade cases (83.8%). The CB grading matched the final FNCLCC grading (low vs high) in 175 (87.9%) of the 199 resected tumors; overestimating the final grade in three cases and underestimating in 21 cases. Modified system 1 (Ki-67) accurately identified 117 of the 130 high-grade cases (90.0%). The CB grading matched the final FNCLCC grading (low vs high) in 175 (89.7%) of the 195 evaluated cases; overestimating seven and underestimating 13 cases. Modified system 2 (Ki-67 plus radiological necrosis) accurately identified 120 of the 130 high-grade cases (92.3%). This last matched the final FNCLCC grading (low vs high) in 177 (91.2%) of the 194 evaluated cases; overestimating seven and underestimating 10 cases. Modified system 2 obtained highest area under ROC curves, although not statistically significant. Underestimated CB grades did not correlate with histological subtypes, although many of the discrepant cases were myxoid tumors (myxofibrosarcomas or myxoid liposarcomas), leiomyosarcomas or undifferentiated pleomorphic/spindle cell sarcomas. Using modified FNCLCC CB grading systems to replace conventional mitotic count and histologic assessment of necrosis may improve the distinction between low and high-grade STS on CB. Our study confirms that classifying grade 1 as low grade and grades 2 and 3 as high grade improves correlation between CB and final grade by up to 21%, irrespective of CB system used. A higher than expected Ki-67 score in a low-grade sarcoma diagnosed on CB should raise concern that a higher-grade component may not have been sampled. Furthermore, correlation of all clinicopathological and radiological findings at multidisciplinary meetings is essential to assess the histological grade on CB as accurately as possible.

Follow-up Strategies for Primary Extremity Soft-tissue Sarcoma in Adults: A Systematic Review of the Published Literature

AIM

Follow-up strategies for primary extremity soft-tissue sarcomas (eSTS) in adults were evaluated in a systematic review of the published literature.

MATERIAL AND METHODS

The published literature was reviewed using PubMed. Of 136,646 studies published between 1985 and 2019, 78 original articles met the inclusion criteria. Articles were selected on the basis of the PRISMA guidelines. The selected articles were then cross-searched to identify further publications. August 1, 2019 was used as the concluding date of publication.

RESULTS

A variety of follow-up schedules have been reported in recently published literature. Two official guidelines have been approved by international societies. The guidelines distinguish between high- and low-grade STS, but mention a wide range of follow-up intervals. Established tools of follow-up include computed tomograph, X-rays of the chest, and magnetic resonance imaging of the primary tumor site in addition to clinical observation and physical examination.

CONCLUSION

Further research will be needed to establish evidence-based guidelines and schedules for follow-up strategies in patients with eSTS.

Adjuvant high-dose-rate interstitial brachytherapy for malignant peripheral nerve sheath tumor of the foot: a case report

Soft tissue sarcomas of the foot are extremely rare and can therefore be misdiagnosed as benign diseases, and be prematurely removed with an unplanned excision. The standard treatment is a wide local excision with an addition of radiotherapy as an alternative to a radical resection (e.g., below-knee or foot amputation). We report on a patient with primary malignant peripheral nerve sheath tumor in the foot plantar soft tissue, who had no evidence of the disease and no severe late toxicity higher than grade 2, 40 months after receiving amputation of toes and adjuvant interstitial high-dose-rate brachytherapy (HDR-BT). To the best of our knowledge, only a few cases were treated with HDR-BT with this scenario. From our findings, HDR-BT could be a safe and quick treatment option for these types of lesions.

Imaging of Soft Tissue Tumors

Differentiation of malignant from benign soft tissue tumors is challenging with imaging alone, including that by magnetic resonance imaging and computed tomography. However, the accuracy of this differentiation has increased owing to the development of novel imaging technology. Detailed patient history and physical examination remain essential for differentiation between benign and malignant soft tissue tumors. Moreover, measurement only of tumor size based on Response Evaluation Criteria In Solid Tumors criteria is insufficient for the evaluation of response to chemotherapy or radiotherapy. Change in metabolic activity measured by ¹⁸F-fluorodeoxyglucose positron emission tomography or dynamic contrast enhanced-derived quantitative endpoints can more accurately evaluate treatment response compared to change in tumor size. Magnetic resonance imaging can accurately evaluate essential factors in surgical planning such as vascular or bone invasion and "tail sign". Thus, imaging plays a critical role in the diagnosis and treatment of soft tissue tumors.

Combining Augmented Reality and 3D Printing to Improve Surgical Workflows in Orthopedic Oncology: Smartphone Application and Clinical Evaluation

During the last decade, orthopedic oncology has experienced the benefits of computerized medical imaging to reduce human dependency, improving accuracy and clinical outcomes. However, traditional surgical navigation systems do not always adapt properly to this kind of interventions. Augmented reality (AR) and three-dimensional (3D) printing are technologies lately introduced in the surgical environment with promising results. Here we present an innovative solution combining 3D printing and AR in orthopedic oncological surgery. A new surgical workflow is proposed, including 3D printed models and a novel AR-based smartphone application (app). This app can display the patient’s anatomy and the tumor’s location. A 3D-printed reference marker, designed to fit in a unique position of the affected bone tissue, enables automatic registration. The system has been evaluated in terms of visualization accuracy and usability during the whole surgical workflow. Experiments on six realistic phantoms provided a visualization error below 3 mm. The AR system was tested in two clinical cases during surgical planning, patient communication, and surgical intervention. These results and the positive feedback obtained from surgeons and patients suggest that the combination of AR and 3D printing can improve efficacy, accuracy, and patients’ experience.

MRI after Whoops procedure: diagnostic value for residual sarcoma and predictive value for an incomplete second resection

OBJECTIVE

To determine the value of MRI for the detection and assessment of the anatomic extent of residual sarcoma after a Whoops procedure (unplanned sarcoma resection) and its utility for the prediction of an incomplete second resection.

MATERIALS AND METHODS

This study included consecutive patients who underwent a Whoops procedure, successively followed by gadolinium chelate-enhanced MRI and second surgery at a tertiary care sarcoma center.

RESULTS

Twenty-six patients were included, of whom 19 with residual tumor at the second surgery and 8 with an incomplete second resection (R1: n = 6 and R2: n = 2). Interobserver agreement for residual tumor at MRI after a Whoops procedure was perfect (κ value: 1.000). MRI achieved a sensitivity of 47.4% (9/19), a specificity of 100% (7/7), a positive predictive value of 100% (9/9), and a negative predictive value of 70.0% (7/17) for the detection of residual tumor. MRI correctly classified 2 of 19 residual sarcomas as deep-seated (i.e., extending beyond the superficial muscle fascia) but failed to correctly classify 3 of 19 residual sarcomas as deep-seated. There were no significant associations between MRI findings (presence of residual tumor, maximum tumor diameter, anatomic tumor extent, tumor margins, tumor spiculae, and tumor tail on the superficial fascia) with an incomplete (R1 or R2) second resection.

CONCLUSION

Gadolinium chelate-enhanced MRI is a reproducible method to rule in residual sarcoma, but it is insufficiently accurate to rule out and assess the anatomic extent or residual sarcoma after a Whoops procedure. Furthermore, MRI has no utility in predicting an incomplete second resection.

Detection of Structural Variants in Circulating Cell-Free DNA from Sarcoma Patients Using Next Generation Sequencing

Circulating tumour DNA (ctDNA) analysis using next generation sequencing (NGS) is being implemented in clinical practice for treatment stratification and disease monitoring. However, using ctDNA to detect structural variants, a common occurrence in sarcoma, can be challenging. Here, we use a sarcoma-specific targeted NGS panel to identify translocations and copy number variants in a cohort of 12 tissue specimens and matched circulating cell-free DNA (cfDNA) from soft tissue sarcoma patients, including alveolar rhabdomyosarcoma (n = 2), Ewing's Sarcoma (n = 2), synovial sarcoma (n = 2), extraskeletal myxoid chondrosarcoma (n = 1), clear cell sarcoma (n = 1), undifferentiated round cell sarcoma (n = 1), myxoid liposarcoma (n = 1), alveolar soft part cell sarcoma (n = 1) and dedifferentiated liposarcoma (n = 1). Structural variants were detected in 11/12 (91.6%) and 6/12 (50%) of tissue and plasma samples, respectively. Structural variants were detected in cfDNA at variant allele frequencies >0.2% with an average sequencing depth of 1026×. The results from this cohort show clinical potential for using NGS in ctDNA to aid in the diagnosis and clinical monitoring of sarcomas and warrant additional studies in larger cohorts.

Epithelioid sarcoma of the hand: a wolf in sheep's clothing

Epithelioid sarcoma (ES) of the hand is a rare, aggressive cutaneous malignancy with high rates of recurrence, metastases and mortality. With an incidence rate of 0.4 cases/y per one million population, which compromise for approximately 1-1.4% of all soft tissue sarcoma, ES accounts for 10% of soft tissues sarcomas of the hand and foot. Its aggressiveness and propensity to spread and metastases without being noticed, makes it unique and potentially lethal. Missed or delayed diagnosis are often encountered as this tumor can mimic variety of different entities and due to the infrequent nature of this lesion, treatment options are still controversial. The authors provide systemic review of the current literature on epidemiology, etiology, pathogenesis, management and outcomes of this disease as well as a case presentation and a proposed treatment algorithm. The choice of treatment option depends on disease characteristics, staging at presentation, regional lymph node involvement, comorbidities and performance status of the patient. Emphasis on a multidisciplinary coordinated care is crucial as early diagnosis and treatment can decrease morbidity and mortality rates.

A novel next generation sequencing approach to improve sarcoma diagnosis

Sarcoma is a rare disease affecting both bone and connective tissue and with over 100 pathologic entities, differential diagnosis can be difficult. Complementing immune-histological diagnosis with current ancillary diagnostic techniques, including FISH and RT-PCR, can lead to inconclusive results in a significant number of cases. We describe here the design and validation of a novel sequencing tool to improve sarcoma diagnosis. A NGS DNA capture panel containing probes for 87 fusion genes and 7 genes with frequent copy number changes was designed and optimized. A cohort of 113 DNA samples extracted from soft-tissue and bone sarcoma FFPE material with clinical FISH and/or RT-PCR results positive for either a translocation or gene amplification was used for validation of the NGS method. Sarcoma-specific translocations or gene amplifications were confirmed in 110 out of 113 cases using FISH and/or RT-PCR as gold-standard. MDM2/CDK4 amplification and a total of 25 distinct fusion genes were identified in this cohort of patients using the NGS approach. Overall, the sensitivity of the NGS panel is 97% with a specificity of 100 and 0% failure rate. Targeted NGS appears to be a feasible and cost-effective approach to improve sarcoma subtype diagnosis with the ability to screen for a wide range of genetic aberrations in one test.

Functional image in soft tissue sarcomas: An update of the indications of 18F-FDG-PET/CT

Soft tissue sarcomas (STS) are a rare and heterogeneous group of tumors. They account for 1% of solid malignant tumors in adults and 7% in children and are responsible for 2% of cancer mortality. They require a multidisciplinary approach in centers with experience. This collaboration aims to update the scientific evidence to strengthen, together with clinical experience, the bases for the use and limitations of ¹⁸F-FDG-PET/CT in STSs. The general recommendations for the use of PET/CT in STS at present are summarized as the initial evaluation of soft tissue tumours when conventional image does not establish benignity with certainty and this determines the approach; in biopsy guiding in selected cases; in the initial staging, as additional tool, for rhabdomyosarcoma and STS of extremities or superficial trunk and head and neck tumours; in the suspicion of local recurrence when the CT or MRI are inconclusive and in the presence of osteosynthesis or prosthetic material and in assessment of therapy response to local/systemic therapy in stages ii/iii. In addition, PET/CT has the added value of being a surrogate marker of the histopathological response and it provides prognostic information, both in the baseline study and after treatment.

Hyperprogression of Liver Metastasis With Neoadjuvant Immunotherapy for Soft Tissue Sarcoma

Hyperprogression associated with immunotherapy has been reported previously with melanoma, non-small cell lung cancer (NSCLC), renal, and urothelial cancers but not with sarcoma. A 63-year old man with a biopsy-proven, localized 13 cm high-grade myxoid/round cell liposarcoma of the thigh was treated with concurrent, neoadjuvant checkpoint inhibitor immunotherapy and radiotherapy. After his subsequent wide surgical resection, he developed small hepatic lesions that rapidly progressed and caused his death, raising the possibility of hyperprogression in this entity.

Evaluation of the accuracy of algorithms to identify soft tissue sarcoma (STS) in administrative claims

Background

Lack of using a validated algorithm to select patients is a source of selection bias in oncology studies using administrative claims. The objective of this study to evaluate published algorithms to identify patients with soft tissue sarcoma (STS) in administrative claims and to evaluate new algorithms to improved performance.

Methods

Two cancer populations including STS cases and non-STS controls were selected from the MarketScan Explorys Linked Claims-Electronic Medical Record (EMR) Database between January 1, 2000 and July 31, 2018. Eligible cases had a diagnosis on a clinical record for STS in the EMR while controls had no evidence of STS on any EMR records. Both cases and controls were enrolled in administrative claims during a period of observation and were aged ≥ 18 years. A split sample was used to test and validate algorithms using data from administrative claims. Values for sensitivity, specificity, and positive predictive value (PPV) were calculated for 14 algorithms. Prior literature validating algorithms in administrative claims across other cancer types report both sensitivity and specificity ranging from as low as 73% to as high as 95%. This was used as a benchmark for defining algorithm success.

Results

There were 784 STS cases and 249,062 non-STS cancer controls eligible for analysis. Requiring at least two claims with an ICD-CM diagnosis code for STS achieved a sensitivity of 67% but had a specificity of 72%. Algorithms that required NCCN-recommended systemic treatment for STS improved the specificity to over 90% but dropped the sensitivity to below 20%. Other combinations of diagnostic tests, symptoms, and procedures did not improve performance.

Conclusions

The algorithms tested in this study sample did not achieve sufficient performance and suggest the ability to accurately identify the STS population in administrative data is problematic. Difficulties are likely due to the origin of STS in a variety of locations, the non-specific symptoms of STS, and the common diagnostic tests recommended to diagnose the disease. Future research applying machine learning to examine timing and patterns of variables that comprise the diagnostic process may further investigate the ability to accurately identify STS cases in claims databases.

Multidisciplinary treatment of soft tissue sarcomas: An update

Standard treatment for soft tissue sarcoma, based on complete surgical resection with or without adjuvant radiotherapy and chemotherapy, has not substantially changed during the last several decades. Nevertheless, recent advances have contributed to considerable improvement in the management of these patients; for example, new magnetic resonance imaging sequences such as diffusion-weighted imaging and magnetic resonance imaging radiomics can better assess tumor extension and even estimate its grade. Detection of circulating genetic material (liquid biopsy) and next-generation sequencing are powerful techniques for genetic analysis, which will increase our understanding of the underlying molecular mechanisms and may reveal potential therapeutic targets. The role of chemotherapy in non-metastatic disease is still controversial, and there is a need to identify patients who really benefit from this treatment. Novel chemotherapeutic regimens have entered clinical praxis and can change the outcome of patients with metastatic disease. Advances in radiotherapy have helped decrease local adverse effects and sustain good local control of the disease. The following report provides an updated view of the diagnosis, treatment, and future perspectives on the management of patients with soft tissue sarcomas.

Soft Tissue Tumors of the Extremity

Although the vast majority of soft tissue extremity masses are benign, approximately 13,000 people in the United States were diagnosed with soft tissue sarcoma in 2019. This article focuses on the optimal workup of soft tissue masses including the indications for ultrasound and MRI, as well as use of preoperative core needle biopsy. Current AJCC staging, surgical principles of soft tissue sarcoma management, and data regarding indications for radiation therapy and chemotherapy are reviewed. As up to 50% of patients with soft tissue sarcoma will develop recurrent disease, surgical management of locally recurrent and distant metastatic disease is discussed.

Advances in image enhancement for sarcoma surgery

The recurrence rate of soft tissue and bone sarcomas strongly correlates to the status of the surgical margin after excision, yet excessive removal of tissue may lead to distinct, otherwise avoidable morbidity. Therefore, adequate margination of sarcomas both pre- and intra-operatively is a clinical necessity that has not yet fully been met. Current guidance for soft-tissue sarcomas recommends an ultrasound scan followed by magnetic resonance imaging (MRI). For bone sarcomas, two plane radiographs are required, followed similarly by an MRI scan. The introduction of more precise imaging modalities may reduce the morbidity associated with sarcoma surgery; the PET-CT and PET-MRI approaches in particular demonstrating high clinical efficacy. Despite advancements in the accuracy in pre-operative imaging, translation of an image to surgical margins is difficult, regularly resulting in wider resection margins than required. For soft tissue sarcomas there is currently no standard technique for image guided resections, while for bone sarcomas fluoroscopy may be used, however margins are not easily discernible during the surgical procedure. Near infra-red (NIR) fluorescence guided surgery offers an intra-operative modality through which complete tumour resection with adequate tumour-free margins may be achieved, while simultaneously minimising surgical morbidity. NIR imaging presents a potentially valuable adjunct to sarcoma surgery. Early reports indicate that it may be able to provide the surgeon with helpful information on anatomy, perfusion, lymphatic drainage, tumour margins and metastases. The use of NIR fluorochromes have also been demonstrated to be well tolerated by patients. However, prior to widespread implementation, studies related to cost-effectiveness and the development of protocols are essential. Nevertheless, NIR imaging may become ubiquitous in the future, carrying the potential to transform the surgical management of sarcoma.

Emerging therapeutic approaches for canine sarcomas: Pushing the boundaries beyond the conventional

Sarcomas represent a group of genomically chaotic, highly heterogenous tumours of mesenchymal origin with variable mutational load. Conventional therapy with surgery and radiation therapy is effective for managing small, low-grade sarcomas and remains the standard therapeutic approach. For advanced, high-grade, recurrent, or metastatic sarcomas, systemic chemotherapy provides minimal benefit, therefore, there is a drive to develop novel approaches. The discovery of "Coley's toxins" in the 19th century, and their use to stimulate the immune system supported the application of unconventional therapies for the treatment of sarcomas. While promising, this initial work was abandoned and treatment paradigm and disease course of sarcomas was largely unchanged for several decades. Exciting new therapies are currently changing treatment algorithms for advanced carcinomas and melanomas, and similar approaches are being applied to advance the field of sarcoma research. Recent discoveries in subtype-specific cancer biology and the identification of distinct molecular targets have led to the development of promising targeted strategies with remarkable potential to change the landscape of sarcoma therapy in dogs. The purpose of this review article is to describe the current standard of care and limitations as well as emerging approaches for sarcoma therapy that span many of the most active paradigms in oncologic research, including immunotherapies, checkpoint inhibitors, and drugs capable of cellular metabolic reprogramming.

Efficacy and Safety of Microsurgery in Interdisciplinary Treatment of Sarcoma Affecting the Bone

Background: Sarcomas are tumors of mesenchymal origin with high variation in anatomical localization. Sarcomas affecting the bone often require an interdisciplinary resection and reconstruction approach. However, it is critical that microsurgical reconstruction strategies do not negatively impact tumor safety and overall survival, as limb salvage is only the secondary goal of tumor surgery. Here, we analyzed the efficacy and safety of microsurgery in interdisciplinary treatment of sarcoma affecting the bone.

Patients and Methods: We performed a retrospective chart review of all patients treated for soft-tissue and bone sarcoma at the senior author's institution with a focus on bone affection and microsurgical reconstruction between 2000 and 2019. This particular subgroup was further investigated for tumor resection status, 5-year survival rate, length of hospital stay, as well as overall complication and amputation rates.

Results: Between 2000 and 2019, 803 patients were operated for sarcoma resection and reconstruction by the Department of Plastic and Hand Surgery. Of these, 212 patients presented with sarcoma of the extremity affecting the bone. Within this subgroup, 40 patients required microsurgical reconstruction for limb salvage, which was possible in 38 cases. R0 resection was achieved in 93.8%. The 5-year survival was 96.7%, and the overall complication rate was 25%, of which 40% were microsurgery associated complications.

Conclusion: Safe and function-preserving treatment of soft-tissue and bone sarcoma is challenging. Primary reconstruction with microsurgical techniques of sarcoma-related defects enables limb-sparing and adequate oncosurgical cancer treatment without increasing the risk for local recurrence or prolonged hospital stay. The treatment of sarcoma patients should be reserved to high-volume centers with experienced plastic surgeon embedded in a comprehensive treatment concept.

Diagnosis and Management of Subcutaneous Soft Tissue Sarcoma

OPINION STATEMENT

The proper diagnosis and treatment planning for subcutaneous soft tissue sarcoma is very important. Soft tissue tumors can occur anywhere in the body, but if they occur subcutaneously, patients can easily notice a subcutaneous soft tissue mass. Therefore, it is possible to determine through recording, the growth speed of the mass, which is often difficult to obtain with deep-situated soft tissue masses. Palpation can also provide information about the firmness and mobility of the mass. Thus, history taking and physical examinations are informative for subcutaneous soft tissue tumors, compared to tumors that occur deeply. Because subcutaneous soft tissue tumors are easily recognized, they are often resected, without sufficient imaging analyses or thorough treatment planning. An operation performed based on such an inadequate preoperative plan is called a "whoops surgery." In the case of "whoops surgeries," subsequent radical surgery is required to remove additional areas, including hematomas that result from the initial surgery, that require a wider range of resection and soft tissue reconstruction. Therefore, as with deep-seated soft tissue tumors, it is important to conduct careful imaging examinations and make appropriate preoperative plans for subcutaneous soft tissue tumors. Subcutaneous soft tissue sarcomas often show an invasive pattern, and such tumors require a more careful assessment to prevent local recurrence after surgery. During surgery, it is necessary to remove the entire infiltration area along the fascia. Sometimes, an adequately wide excision is necessary, which is considered the minimum necessary procedure to eradicate the lesion. As noted above, clinicians who see patients with subcutaneous soft tissue tumors are encouraged to have sufficient knowledge and experience regarding the diagnosis and treatment. This article is intended for all doctors who deal with subcutaneous soft tissue tumors and focuses on essential points regarding their diagnosis and management.

Clinical Characteristics and Surgical Outcomes of Limb-Sparing Surgery with Vascular Reconstruction for Soft Tissue Sarcomas

BACKGROUND

The standard treatment for lower extremity soft tissue sarcoma (STS) is limb-sparing surgery. For a small subset of patients, concomitant vascular reconstruction may be required to preserve limb viability and function while completely excising the tumor with an adequate resection margin. The aim of this study was to evaluate the surgical outcomes and clinical characteristics of patients with STS of the extremities requiring vascular reconstructions.

METHODS

From January 2002 through December 2014, 13 patients with limb STS presenting with vascular invasion underwent surgical resection, followed by vascular reconstruction. The medical records such as demographics, histopathological findings, complications, success of vascular reconstruction, and clinical and oncological outcomes were retrospectively reviewed from a prospectively collected clinical database.

RESULTS

With a mean follow-up period of 80.6 months, a total of 24 vascular reconstruction procedures (1 only arterial, 1 only venous, and 11 both arterial and venous) were performed. Contralateral great saphenous vein graft was the conduit of choice for vascular replacement. Five graft thromboses were observed in 4 patients. Arterial occlusion occurred in two cases, and venous bypasses occluded in three patients. The overall five-year patency for arterial and venous reconstructions was 84.6% and 75.2%, respectively. The mean survival period of patients was 105.5 months, with a 5-year disease-free survival rate and overall survival rate of 59.3% and 68.4%, respectively.

CONCLUSIONS

Vascular resection and reconstruction for STSs of extremity can be safely performed with acceptable short- and long-term surgical and oncological outcomes. Regardless of the surgical procedure, amputation or limb-sparing surgery, the primary focus should be to adhere to strict oncological principles. In addition, because of the complexity of these tumors, an appropriate preoperative planning and meticulous multidisciplinary approach are also crucial.