Looking for answers: the current status of neoadjuvant treatment in localized soft tissue sarcomas

Extremity and Truncal Soft Tissue Sarcoma: Risk Assessment and Multidisciplinary Management

Extremity and truncal soft tissue sarcomas are a heterogeneous group of rare cancers that arise from mesenchymal tissues. Hence, the adoption of tailored risk assessment and prognostication tools plays a crucial role in optimizing the decision-making for which of the many possible treatment strategies to select. Management of these tumors requires a multidisciplinary strategy, which has seen significant development in recent decades. Surgery has emerged as the primary treatment approach, with the main goal of achieving microscopic negative tumor margins. To reduce the likelihood of local recurrence, loco-regional treatments such as radiation therapy and isolated limb perfusion are often added to the treatment regimen in combination with surgery. This approach also enables surgeons to perform limb-sparing surgery, particularly in cases where a positive tumor margin is expected. Chemotherapy may also provide a further benefit in decreasing the probability of local recurrence or reducing distant metastasis in selected patients. Selecting the optimal treatment strategy for these rare tumors is best accomplished by an experienced multi-disciplinary team.

Similar additive effects of doxorubicin in combination with photon or proton irradiation in soft tissue sarcoma models

High-precision radiotherapy with proton beams is frequently used in the management of aggressive soft tissue sarcoma (STS) and is often combined with doxorubicin (Dox), the first-line chemotherapy for STS. However, current treatment approaches continue to result in high local recurrence rates often occurring within the treatment field. This strongly indicates the need of optimized treatment protocols taking the vast heterogeneity of STS into account, thereby fostering personalized treatment approaches. Here, we used preclinical STS models to investigate the radiation response following photon (X) or proton (H) irradiation alone and in combination with different treatment schedules of Dox. As preclinical models, fibrosarcoma (HT-1080), undifferentiated pleiomorphic sarcoma (GCT), and embryonal rhabdomyosarcoma (RD) cell lines were used; the latter two are mutated for TP53. The cellular response regarding clonogenic survival, apoptosis, cell-cycle distribution, proliferation, viability, morphology, and motility was investigated. The different STS cell types revealed a dose-dependent radiation response with reduced survival, proliferation, viability, and motility whereas G2/M phase arrest as well as apoptosis were induced. RD cells showed the most radiosensitive phenotype; the linear quadratic model fit could not be applied. In combined treatment schedules, Dox showed the highest efficiency when applied after or before and after radiation; Dox treatment only before radiation was less efficient. GCT cells were the most chemoresistant cell line in this study most probably due to their TP53 mutation status. Interestingly, similar additive effects could be observed for X or H irradiation in combination with Dox treatment. However, the additive effects were determined more frequently for X than for H irradiation. Thus, further investigations are needed to specify alternative drug therapies that display superior efficacy when combined with H therapy.

Neoadjuvant radiation improves margin-negative resection rates in extremity sarcoma but not survival

BACKGROUND AND OBJECTIVES

Radiation improves limb salvage in extremity sarcomas. Timing of radiation therapy remains under investigation. We sought to evaluate the effects of neoadjuvant radiation (NAR) on surgery and survival of patients with extremity sarcomas.

MATERIALS AND METHODS

A multi-institutional database was used to identify patients with extremity sarcomas undergoing surgical resection from 2000-2016. Patients were categorized by treatment strategy: surgery alone, adjuvant radiation (AR), or NAR. Survival, recurrence, limb salvage, and surgical margin status was analyzed.

RESULTS

A total of 1483 patients were identified. Most patients receiving radiotherapy had high-grade tumors (82% NAR vs 81% AR vs 60% surgery; P < .001). The radiotherapy groups had more limb-sparing operations (98% AR vs 94% NAR vs 87% surgery; P < .001). NAR resulted in negative margin resections (90% NAR vs 79% surgery vs 75% AR; P < .0001). There were fewer local recurrences in the radiation groups (14% NAR vs 17% AR vs 27% surgery; P = .001). There was no difference in overall or recurrence-free survival between the three groups (OS, P = .132; RFS, P = .227).

CONCLUSION

In this large study, radiotherapy improved limb salvage rates and decreased local recurrences. Receipt of NAR achieves more margin-negative resections however this did not improve local recurrence or survival rates over.

Diagnostic yield of percutaneous core needle biopsy in suspected soft tissue lesions of extremities

OBJECTIVE

This retrospective study was performed to investigate the diagnostic yield of percutaneous core needle biopsy (CNB) for suspected soft tissue lesions of the extremities.

METHODS

The medical records of 139 consecutive patients who underwent percutaneous CNB for suspected soft tissue lesions of the extremities from January 2014 to December 2016 at a single institution were reviewed. The pathologic findings or clinical follow-ups were used to evaluate the performance of CNB. Alterations in the treatment regimen from pre- to post-biopsy were also analyzed. Complications, when present, were documented.

RESULTS

In total, 141 biopsy procedures were performed in 139 patients. In total, 136 (96%) biopsies were successful, among which 5 were false-negative and 131 were diagnosed accurately. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CNB in the differentiation of malignant from benign lesions were 94%, 100%, 96%, 100%, and 90%, respectively. The treatment regimen was altered based on the biopsy findings in 25 cases. Two patients developed mild nerve injury but fully recovered during follow-up.

CONCLUSIONS

CNB is effective and safe, with high sensitivity, specificity, and accuracy for the diagnosis of soft tissue lesions, especially for differentiating malignant from benign lesions.

The impact of chemotherapy on survival of patients with extremity and trunk wall soft tissue sarcoma: revisiting the results of the EORTC-STBSG 62931 randomised trial

BACKGROUND

This study was aimed at determining whether patients with high-risk soft tissue sarcoma (STS), as identified using the nomogram Sarculator, benefitted from adjuvant chemotherapy in the EORTC-STBSG 62931 randomised controlled trial (RCT), which failed to detect an impact for adjuvant doxorubicin plus ifosfamide (Adj) over observation (Obs).

METHODS

Patients with extremity and trunk wall STS in the EORTC-STBSG 62931 RCT were analysed (N = 290/351). Ten-year predicted probability of overall survival (pr-OS) was calculated using the prognostic nomogram Sarculator. Patients were grouped into three categories of predicted pr-OS: high (pr-OS>66%), intermediate (51<pr-OS≤66) and low (pr-OS≤51%). OS and disease-free survival (DFS) were calculated.

RESULTS

Nomogram pr-OS was dispersed (median 72%, interquartile range 57-83%) and had prognostic value for OS and DFS (log-rank test: P < 0.001). One hundred seventy, 68 and 52 patients had high (58.6%, 90 Obs/80 Adj), intermediate (23.5%, 34 Obs/34 Adj) and low pr-OS (17.9%, 24 Obs/28 Adj), respectively. Adjuvant chemotherapy halved the risk of recurrence (hazard ratio [HR] = 0.46, 95% confidence interval [CI] 0.24-0.89) and death (HR = 0.46, 95% CI 0.23-0.94) in the low pr-OS category, while no effect was detected in intermediate and high pr-OS categories. To strengthen these findings, study participants with pr-OS<60% were combined (N = 80, 27.6%, 39 Obs/41 Adj), and a significant DFS (HR = 0.49, 95% CI 0.28-0.85) and OS (HR = 0.50, 95% CI 0.30-0.90) benefit was detected.

CONCLUSION

Patients of the EORTC-STBSG 62931 RCT with extremity and trunk wall STS and a low predicted pr-OS (high-risk patients) had better outcomes when treated with adjuvant chemotherapy. This may help reconcile the disparate results of clinical studies on adjuvant/neoadjuvant chemotherapy in STS.

Design, Synthesis, and Characterization of Globular Orphan Nuclear Receptor Regulator with Biological Activity in Soft Tissue Sarcoma

Sarcomas are rare and heterogeneous cancer variants of mesenchymal origin. Their genetic heterogeneity coupled with uncertain histogenesis makes them difficult to treat and results in poor prognosis. In this work, we show that structure-based drug discovery involving computational modeling can be used to identify a new retinoid X receptor (RXR) agonist ligand with a bis(indolyl)methane scaffold. This agent co-self-assembles with an amphiphilic diblock copolymer resulting in nanoparticles (Nano-RXR) with excellent kinetic stability, which were evaluated for efficacy and safety in transformed sarcoma cells, 63-3 Cre and 141-10 Cre of pig origin, and in rodent xenograft models. Responses at gene and protein levels established the treatment approach as a highly effective RXR agonist across cell, rodent, and "Oncopig" models. Interestingly, Nano-RXR was not only able to modulate metabolic and transporter genes related to orphan nuclear receptors but also played a major role in modulating programmed cell death in sarcomas developed in Oncopigs.

Neoadjuvant and adjuvant strategies in retroperitoneal sarcoma

Extended surgery remains the mainstay of treatment in retroperitoneal sarcoma, although conflicting data exist on the benefit of neoadjuvant and adjuvant therapies, particularly with regard to tumour grade and histological type. Experience of radiotherapy and chemotherapy in extremity soft tissue sarcoma can inform treatment strategies, however these data cannot be universally extrapolated to the retroperitoneum where disease biology and anatomical considerations are different. The present review sets a historical context before discussing recent evidence and on-going multi-centre trials in retroperitoneal sarcoma. Promising data on histologically- and molecularly-targeted chemotherapy are discussed and the need for centralisation of retroperitoneal sarcoma services in order to facilitate large international collaborative trials is emphasised.

A vimentin binding small molecule leads to mitotic disruption in mesenchymal cancers

Expression of the transcription factor FOXC2 is induced and necessary for successful epithelial-mesenchymal transition, a developmental program that when activated in cancer endows cells with metastatic potential and the properties of stem cells. As such, identifying agents that inhibit the growth of FOXC2-transformed cells represents an attractive approach to inhibit chemotherapy resistance and metastatic dissemination. From a high throughput synthetic lethal screen, we identified a small molecule, FiVe1, which selectively and irreversibly inhibits the growth of mesenchymally transformed breast cancer cells and soft tissue sarcomas of diverse histological subtypes. FiVe1 targets the intermediate filament and mesenchymal marker vimentin (VIM) in a mode which promotes VIM disorganization and phosphorylation during metaphase, ultimately leading to mitotic catastrophe, multinucleation, and the loss of stemness. These findings illustrate a previously undescribed mechanism for interrupting faithful mitotic progression and may ultimately inform the design of therapies for a broad range of mesenchymal cancers.

Neoadjuvant Radiotherapy is Associated with R0 Resection and Improved Survival for Patients with Extremity Soft Tissue Sarcoma Undergoing Surgery: A National Cancer Database Analysis

BACKGROUND

Neoadjuvant radiotherapy (RT) is increasingly advocated for the management of soft tissue sarcoma (STS). Therefore, this study sought to characterize the impact of neoadjuvant RT on rates of R0 resection and overall survival (OS) in extremity STS patients undergoing surgery.

METHODS

From January 2003 to December 2012, the study identified patients with a diagnosis of extremity STS from the National Cancer Database. After exclusion of patients younger than 18 years, not treated by surgery, who had metastases at diagnosis, intraoperative RT, and missing or unknown data, 27,969 patients were identified. Logistic regression and Cox-proportional hazard analysis were used to compare rates of R0 resection among preoperative, postoperative, and no-RT cohorts and to determine predictors of R0 resection and OS.

RESULTS

The mean age of the patients was 59.5 ± 17.1 years, and 45.9% were female. The median tumor size was 10.5 cm. The data showed that 51% of the patients did not receive RT, 11.8% received preoperative RT, and 37.2% received postoperative RT. The rates of R0 resection were 90.1% for the preoperative RT cohort, 74.9% for the postoperative RT cohort, and 79.9% for the no-RT cohort (P < 0.001). The independent predictors for achievement of R0 resection included academic facility type (odds ratio [OR] 1.36; 95% confidence interval [CI] 1.20-1.55), histologic subtype, tumor size (OR 0.99; 95% CI 0.99-0.99), Charlson score (OR 0.92; 95% CI 0.84-0.99), and preoperative RT (OR 1.83; 95% CI 1.61-2.07). Both R0 resection and RT (pre- or post-operative) were associated with increased OS.

CONCLUSIONS

Preoperative RT independently predicts higher rates of R0 resection for patients with extremity STS undergoing surgical resection. Negative surgical margins and pre- or postoperative RT are associated with improved OS.

UK guidelines for the management of soft tissue sarcomas

Soft tissue sarcomas (STS) are rare tumours arising in mesenchymal tissues, and can occur almost anywhere in the body. Their rarity, and the heterogeneity of subtype and location means that developing evidence-based guidelines is complicated by the limitations of the data available. However, this makes it more important that STS are managed by teams, expert in such cases, to ensure consistent and optimal treatment, as well as recruitment to clinical trials, and the ongoing accumulation of further data and knowledge. The development of appropriate guidance, by an experienced panel referring to the evidence available, is therefore a useful foundation on which to build progress in the field. These guidelines are an update of the previous version published in 2010 (Grimer et al. in Sarcoma 2010:506182, 2010). The original guidelines were drawn up following a consensus meeting of UK sarcoma specialists convened under the auspices of the British Sarcoma Group (BSG) and were intended to provide a framework for the multidisciplinary care of patients with soft tissue sarcomas. This current version has been updated and amended with reference to other European and US guidance. There are specific recommendations for the management of selected subtypes of disease including retroperitoneal and uterine sarcomas, as well as aggressive fibromatosis (desmoid tumours) and other borderline tumours commonly managed by sarcoma services. An important aim in sarcoma management is early diagnosis and prompt referral. In the UK, any patient with a suspected soft tissue sarcoma should be referred to one of the specialist regional soft tissues sarcoma services, to be managed by a specialist sarcoma multidisciplinary team. Once the diagnosis has been confirmed using appropriate imaging, plus a biopsy, the main modality of management is usually surgical excision performed by a specialist surgeon. In tumours at higher risk of recurrence or metastasis pre- or post-operative radiotherapy should be considered. Systemic anti-cancer therapy (SACT) may be utilized in some cases where the histological subtype is considered more sensitive to systemic treatment. Regular follow-up is recommended to assess local control, development of metastatic disease, and any late-effects of treatment. For local recurrence, and more rarely in selected cases of metastatic disease, surgical resection would be considered. Treatment for metastases may include radiotherapy, or systemic therapy guided by the sarcoma subtype. In some cases, symptom control and palliative care support alone will be appropriate.