The role of radiotherapy in the management of localized soft tissue sarcomas

Development and external validation of a machine learning model for prediction of survival in extremity leiomyosarcoma

PURPOSE

Machine learning (ML) models have been used to predict cancer survival in several sarcoma subtypes. However, none have investigated extremity leiomyosarcoma (LMS). ML is a powerful tool that has the potential to better prognosticate extremity LMS.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for cases of histologic extremity LMS (n = 634). Patient, tumor, and treatment characteristics were recorded, and ML models were developed to predict 1-, 3-, and 5-year survival. The best performing ML model was externally validated using an institutional cohort of extremity LMS patients (n = 46).

RESULTS

All ML models performed best at the 1-year time point and worst at the 5-year time point. On internal validation within the SEER cohort, the best models had c-statistics of 0.75-0.76 at the 5-year time point. The Random Forest (RF) model was the best performing model and used for external validation. This model also performed best at 1-year and worst at 5-year on external validation with c-statistics of 0.90 and 0.87, respectively. The RF model was well calibrated on external validation. This model has been made publicly available at https://rachar.shinyapps.io/lms_app/ CONCLUSIONS: ML models had excellent performance for survival prediction of extremity LMS. Future studies incorporating a larger institutional cohort may be needed to further validate the ML model for LMS prognostication.

Effects of Neoadjuvant Radiation and Recipient Vessel Characteristics on Microvascular Complication Rates in Reconstruction of Lower Extremity Soft Tissue Sarcoma Defects

BACKGROUND

 The treatment approach for soft tissue sarcomas (STS) of the lower extremity has shifted toward the use of neoadjuvant radiation combined with limb-sparing surgery (LSS). The resulting defects often require reconstruction with free tissue transfer for adequate outcomes. Data have demonstrated a potentially increased risk of microvascular complications for free flaps performed using irradiated recipient vessels. Similarly, certain anatomic areas of the lower extremity have a high proportion of unnamed perforators that are available as recipient vessels, increasing the technical difficulty. We aimed to determine if the characteristics of recipient vessels that were used for the reconstruction of STS defects influenced rates of microvascular complications in our patients.

METHODS

 A retrospective chart review of all patients who underwent reconstruction of lower extremity STS defects with free tissue transfer from 2009 to 2020 was conducted. Data regarding recipient vessel type (axial vessel vs. unnamed perforator), radiation status of the recipient vessels (irradiated vs. non-irradiated), and microvascular complications were compared across groups.

RESULTS

 A total of 204 free flaps were included. The overall microvascular complication rate was 13.7% (28 cases). Most microvascular complications were detected postoperatively (82.1%) rather than intraoperatively, with the majority involving venous congestion/thrombosis (20 cases, 71.4%). While there was a trend toward increased microvascular complications with the use of irradiated recipient vessels (27 cases, 96.4%), this did not reach statistical significance (OR = 1.98, p = 0.52). The use of perforating branches as recipient vessels did not confer an increased risk of microvascular complications (OR = 0.87, p = 0.75).

CONCLUSION

 The reconstruction of irradiated lower-extremity STS defects represents a particularly challenging issue. This analysis demonstrates that free tissue transfer can be safely performed using irradiated vessels without a significantly increased risk of microvascular complications. Furthermore, unnamed perforating branches can be successfully used for reconstruction in anatomically challenging areas of the lower extremity.

Minimally interactive segmentation of soft-tissue tumors on CT and MRI using deep learning

BACKGROUND

Segmentations are crucial in medical imaging for morphological, volumetric, and radiomics biomarkers. Manual segmentation is accurate but not feasible in clinical workflow, while automatic segmentation generally performs sub-par.

PURPOSE

To develop a minimally interactive deep learning-based segmentation method for soft-tissue tumors (STTs) on CT and MRI.

MATERIAL AND METHODS

The interactive method requires the user to click six points near the tumor's extreme boundaries in the image. These six points are transformed into a distance map and serve, with the image, as input for a convolutional neural network. A multi-center public dataset with 514 patients and nine STT phenotypes in seven anatomical locations, with CT or T1-weighted MRI, was used for training and internal validation. For external validation, another public dataset was employed, which included five unseen STT phenotypes in extremities on CT, T1-weighted MRI, and T2-weighted fat-saturated (FS) MRI.

RESULTS

Internal validation resulted in a dice similarity coefficient (DSC) of 0.85 ± 0.11 (mean ± standard deviation) for CT and 0.84 ± 0.12 for T1-weighted MRI. External validation resulted in DSCs of 0.81 ± 0.08 for CT, 0.84 ± 0.09 for T1-weighted MRI, and 0.88 ± 0.08 for T2-weighted FS MRI. Volumetric measurements showed consistent replication with low error internally (volume: 1 ± 28 mm3, r = 0.99; diameter: - 6 ± 14 mm, r = 0.90) and externally (volume: - 7 ± 23 mm3, r = 0.96; diameter: - 3 ± 6 mm, r = 0.99). Interactive segmentation time was considerably shorter (CT: 364 s, T1-weighted MRI: 258s) than manual segmentation (CT: 1639s, T1-weighted MRI: 1895s).

CONCLUSION

The minimally interactive segmentation method effectively segments STT phenotypes on CT and MRI, with robust generalization to unseen phenotypes and imaging modalities.

KEY POINTS

Question Can this deep learning-based method segment soft-tissue tumors faster than can be done manually and more accurately than other automatic methods? Findings The minimally interactive segmentation method achieved accurate segmentation results in internal and external validation, and generalized well across soft-tissue tumor phenotypes and imaging modalities. Clinical relevance This minimally interactive deep learning-based segmentation method could reduce the burden of manual segmentation, facilitate the integration of imaging-based biomarkers (e.g., radiomics) into clinical practice, and provide a fast, semi-automatic solution for volume and diameter measurements (e.g., RECIST).

The functional and clinical outcomes of primary and metastatic malignancies of the elbow

OBJECTIVES

This study aims to investigate the etiological distribution of primary and metastatic malignancies around the elbow and the effect of surgical and adjuvant treatments on clinical outcome.

PATIENTS AND METHODS

Between January 2006 and December 2020, medical records of a total of 33 patients with elbow neoplasm (15 males, 18 females; median age: 55 years; range, 39 to 71 years) who underwent surgical treatment and with or without clinical treatment were retrospectively analyzed. The outcomes and frequencies of the elbow metastatic and primary malignancies were evaluated. Data were collected from patients' medical and radiological documents, and a dedicated archive was created for this study.

RESULTS

Most tumors occurred on the right side and were intra-articular or distal to the humerus. A total of 75.8% (25/33) of the patients had tumors of any diameter ≥5 cm. Most patients were treated with extensive resection. A total of 81.8% (27/33) of the patients had wide resected tumor margins, and 18.2% (6/33) had intralesional tumor margins. The median follow-up was 42 (range, 1 to 83) months. Synovial sarcoma and malignant peripheral nerve sheath tumors were the most common soft tissue sarcomas, and pulmonary adenoma and multiple myeloma were found in metastatic lesions.

CONCLUSION

Elbow surgery is particularly challenging due to the interrelationship of major neurovascular structures. Synovial sarcoma and malignant peripheral nerve sheath tumors are the most common soft tissue sarcomas, and pulmonary adenoma and multiple myeloma are found in metastatic lesions. Limb-sparing surgery is the gold-standard method recently.

Progressive Improvement in 5-Year Survival Rates for Extremity Soft Tissue Sarcomas from 1999 to 2019

Background

Extremity soft-tissue sarcoma (ESTS) is a group of rare, heterogeneous malignancies. Previous studies have demonstrated a progressive improvement in 5-year survival rate over time, but recent trends are unknown. Therefore, this study aimed to provide an update on the clinical characteristics and 5-year survival rate of ESTS from 1999 to 2019.

Methods

This retrospective cohort study used the Surveillance, Epidemiology, and End Results (SEER) database. Overall, 5,654 patients over the age of 15 years with primary ESTS diagnosed between 1999 and 2019 were included. Data on patient demographics, clinical characteristics, and survival were extracted. Patients were grouped by year of diagnosis: 1999-2005, 2006-2012, and 2013-2019. Kaplan-Meier and Cox proportional hazards regression analyses were performed.

Results

ESTS occurred primarily in the lower extremity (76.1%) and was frequently grade III (58.3%), >5 cm in size (69.9%), and without metastasis (77.9%) at diagnosis. Furthermore, there was a significant increase in the proportion of patients over age 60 (p < 0.001) and without metastasis (p < 0.001) over the study period. The 5-year survival rate successively improved, from 47% in 1999-2005, to 61% in 2006-2012, to 78% in 2013-2019. Similarly, in multivariate analysis, the mortality rate progressively declined from a hazard ratio (HR) of 3.4 in 1999-2005 to an HR of 2.1 in 2006-2012, with the 2013-2019 group having the best overall survival (p < 0.001). Age, tumor size, grade, and metastasis were negative prognostic factors for survival; radiation and surgery were positive prognostic factors.

Conclusions

The 5-year overall survival rate for ESTS progressively improved over the 20-year study period, perhaps due to an increasing proportion of older patients diagnosed with local disease. These findings may also be related to earlier detection or more effective treatment over the study period.

Patterns of Local Recurrence and Risk of Skin Recurrence in Soft Tissue Sarcomas After Surgical Resection

PURPOSE

Although there is a theoretical risk of skin seeding during surgical resection of soft tissue sarcomas (STSs), current consensus guidelines recommend against routine use of bolus during radiation therapy (RT). However, the risk of skin recurrence has not been systematically assessed. We aimed to assess the patterns of local recurrence (LR) in patients with STS treated with surgery with or without RT.

METHODS AND MATERIALS

We performed a retrospective analysis of adults with STSs evaluated at our institution between 2007 and 2021. For patients who developed LR, the depth was evaluated. Progression-free survival and overall survival were analyzed from time of first LR using the Kaplan-Meier method. Cumulative incidence of distant metastasis was calculated with competing risk analysis from date of LR.

RESULTS

Of the 206 patients evaluated, 20 had LR (9.7%). Among patients with LR, 5 patients (25.0%) were treated with surgery alone and 15 patients (75.0%) with surgery and RT. In patients treated with RT, 46.7% had preoperative RT, 53.3% had postoperative RT, and bolus was used in 46.7%. Surgical margins were close (<1 mm) in 4 patients (20.0%) and positive in 10 patients (50.0%). LR occurred in the deep subfascial tissue in 9 patients (45%), subcutaneous tissue in 10 patients (50.0%), and skin in 1 patient (5.0%). The patient with a skin recurrence was treated with surgery alone, and the tumor involved the skin at presentation. In patients treated with RT, LR occurred within the RT field in 13 patients (86.7%). At 1 year after LR, progression-free survival was 70.3%, overall survival was 81.7%, and cumulative incidence of distant metastasis was 5.9%.

CONCLUSIONS

Skin recurrences were rare after surgical resection of STSs and only occurred in a tumor that involved the skin at initial presentation. These findings support current recommendations against routine use of bolus in STSs not involving the skin at presentation.

Immune Cells in the Tumor Microenvironment of Soft Tissue Sarcomas

Soft tissue sarcomas (STSs) are a rare heterogeneous group of malignant neoplasms characterized by their aggressive course and poor response to treatment. This determines the relevance of research aimed at studying the pathogenesis of STSs. By now, it is known that STSs is characterized by complex relationships between the tumor cells and immune cells of the microenvironment. Dynamic interactions between tumor cells and components of the microenvironment enhance adaptation to changing environmental conditions, which provides the high aggressive potential of STSs and resistance to antitumor therapy. Today, active research is being conducted to find effective antitumor drugs and to evaluate the possibility of using therapy with immune cells of STS. The difficulty in assessing the efficacy of new antitumor options is primarily due to the high heterogeneity of this group of malignant neoplasms. Studying the role of immune cells in the microenvironment in the progression STSs and resistance to antitumor therapies will provide the discovery of new biomarkers of the disease and the prediction of response to immunotherapy. In addition, it will help to initially divide patients into subgroups of good and poor response to immunotherapy, thus avoiding wasting precious time in selecting the appropriate antitumor agent.

Integra® Dermal Regeneration Matrix: A Versatile Solution for Complex Soft Tissue Sarcoma Reconstruction in the Hand

This case report describes the successful use of Integra® (Integra LifeSciences Corporation, Plainsboro, New Jersey, United States), an artificial skin substitute, for the reconstruction of soft tissue defects following soft tissue sarcoma resection. We present a case of a 75-year-old female presented with a progressively enlarging lesion on her right hand. Imaging revealed tumor involvement in the extensor tendons and adjacent to the index finger tendon. A percutaneous biopsy confirmed an undifferentiated pleomorphic sarcoma. The patient underwent neoadjuvant radiotherapy followed by wide excision of the tumor. Integra® dermal regeneration matrix was utilized to cover the exposed bone during the surgical procedure. This allowed for wound closure and provided a favorable environment for tissue regeneration and subsequent split-thickness skin graft. Complete wound healing was obtained. Regular follow-up examinations showed no evidence of local recurrence or secondary lesions after one year. The successful use of Integra®, in this case, demonstrates its efficacy as a reconstructive option for complex hand sarcomas. It offers immediate wound coverage and promotes tissue regeneration, thereby avoiding the need for more extensive treatment modalities with associated donor-site morbidity. The utilization of Integra® resulted in high patient satisfaction and excellent recovery. This case highlights the importance of utilizing innovative techniques and materials in achieving optimal outcomes in challenging hand sarcoma reconstructions.

Radiotherapy and Limb-Sparing Surgery in the Management of Localized Soft Tissue Sarcomas: Tertiary Care Center Experience From Pakistan

PURPOSE

When combined with radiotherapy, limb salvage surgery is an alternative to amputation. This study sought to determine the limb-sparing treatment outcomes in patients diagnosed with soft tissue extremity sarcomas treated at our institution.

MATERIALS AND METHODS

All adult patients with extremity soft tissue sarcoma treated with the radical limb salvage strategy at Shaukat Khanum Memorial Cancer Hospital and Research Canter, Lahore, Pakistan, between January 2017 and December 2019 were retrospectively assessed.

RESULTS

A total of 122 patients were included in the study. The mean age was 42 years (range 19-82), and 64 (52.5%) were males. The majority of patients, 65 (53.3%), were diagnosed with stage III and grade III disease according to American Joint Committee on Cancer TNM classification (Eighth edition). The most common surgical modality was wide local excision that was performed in 106 (86.9%) patients. Adjuvant radiation treatment was given in 111 (91%) patients, whereas 11 (9%) patients received neoadjuvant radiation treatment. The mean dose was 58 Gy (range: 46-66 Gy). Eighty-two (67.2%) of the patients were disease-free on post-treatment radiologic scans with disease recurrence observed in 40 (32.8%) patients. The median disease-free survival was 8 months (95% CI, 5.45 to 10.55). Local recurrence and distant metastases developed in 16 (13%) and 24 (20%) patients, respectively.

CONCLUSION

About two thirds of patients with extremity soft tissue sarcoma were successfully treated with limb salvage strategy, surgery, and radiation therapy. However, high rate of relapse warrants further novel strategies in this patient population.

A Size-Based Criteria for Flap Reconstruction After Thigh-Adductor, Soft-Tissue Sarcoma Resection

BACKGROUND

Resection of soft-tissue sarcomas from the adductor compartment is associated with significant complications. Free/pedicled flaps often are used for wound closure, but their effect on healing is unclear. We compared wound complications, oncologic, and functional outcomes for patients undergoing flap reconstruction or primary closure following resection of adductor sarcomas.

METHODS

A total of 177 patients underwent resection of an adductor sarcoma with primary closure (PrC) or free/pedicled flap reconstruction (FR). Patient, tumor, and treatment characteristics were compared, as well as wound complications, oncologic, and functional outcomes (TESS/MSTS87/MSTS93). To examine the relative benefit of flap reconstruction, number needed to treat (NNT) was calculated.

RESULTS

In total, 143 patients underwent PrC and 34 had FR, 68% of which were pedicled. There were few differences in demographic, tumor, or treatment characteristics. No significant difference was found in the rate of wound complications. Length of stay was significantly longer in FR (18 days vs. PrC 8 days; p < 0.01). Oncologic and functional outcomes were similar over 5 years follow-up. Uncomplicated wound healing occurred more often in FR compared with PrC for tumors with ≥15 cm (NNT = 8.4) or volumes ≥ 800 ml (NNT = 8.4). Tumors ≤ 336 ml do not benefit from a flap, whereas those > 600 ml are 1.5 times more likely to heal uneventfully after flap closure.

CONCLUSIONS

Although flap use prolonged hospitalization, it decreased wound healing complications for larger tumors, and in all sized tumors, it demonstrated similar functional and oncologic outcomes to primary closure. Our size-based treatment criteria can help to identify patients with large adductor sarcomas who could benefit from flap reconstruction.

LEVEL OF EVIDENCE III

(Retrospective cohort study).

Biological Adaptations of Tumor Cells to Radiation Therapy

Radiation therapy has been used worldwide for many decades as a therapeutic regimen for the treatment of different types of cancer. Just over 50% of cancer patients are treated with radiotherapy alone or with other types of antitumor therapy. Radiation can induce different types of cell damage: directly, it can induce DNA single- and double-strand breaks; indirectly, it can induce the formation of free radicals, which can interact with different components of cells, including the genome, promoting structural alterations. During treatment, radiosensitive tumor cells decrease their rate of cell proliferation through cell cycle arrest stimulated by DNA damage. Then, DNA repair mechanisms are turned on to alleviate the damage, but cell death mechanisms are activated if damage persists and cannot be repaired. Interestingly, some cells can evade apoptosis because genome damage triggers the cellular overactivation of some DNA repair pathways. Additionally, some surviving cells exposed to radiation may have alterations in the expression of tumor suppressor genes and oncogenes, enhancing different hallmarks of cancer, such as migration, invasion, and metastasis. The activation of these genetic pathways and other epigenetic and structural cellular changes in the irradiated cells and extracellular factors, such as the tumor microenvironment, is crucial in developing tumor radioresistance. The tumor microenvironment is largely responsible for the poor efficacy of antitumor therapy, tumor relapse, and poor prognosis observed in some patients. In this review, we describe strategies that tumor cells use to respond to radiation stress, adapt, and proliferate after radiotherapy, promoting the appearance of tumor radioresistance. Also, we discuss the clinical impact of radioresistance in patient outcomes. Knowledge of such cellular strategies could help the development of new clinical interventions, increasing the radiosensitization of tumor cells, improving the effectiveness of these therapies, and increasing the survival of patients.

Indocyanine Green for Leakage Control in Isolated Limb Perfusion

Sarcomas are characterized by a high metastatic potential and aggressive growth. Despite surgery, chemotherapy plays an important role in the treatment of these tumors. Optimal anti-cancer therapy with maximized local efficacy and minimized systemic side effects has been the object of many studies for a long time. To improve the local efficacy of anti-tumor therapy, isolated limb perfusion with high-dose cytostatic agents has been introduced in surgical oncology. In order to control the local distribution of substances, radiolabeled cytostatic drugs or perfusion solutions have been applied but often require the presence of specialized personnel and result in a certain exposure to radiation. In this study, we present a novel strategy using indocyanine green to track tumor perfusion with high-dose cytostatic therapy. In a rat cadaver model, the femoral vessels were cannulated and connected to a peristaltic pump to provide circulation within the selected limb. The perfusion solution contained indocyanine green and high-dose doxorubicin. An infrared camera enabled the visualization of indocyanine green during limb perfusion, and subsequent leakage control was successfully performed. Histologic analysis of sections derived proximally from the injection site excluded systemic drug dispersion. In this study, the application of indocyanine green was proven to be a safe and cost- and time-efficient method for precise leakage control in isolated limb perfusion with a high-dose cytostatic agent.

Technical illustration of Volumetric arc conformal radiotherapy planning in a case of paratesticular sarcoma

Introduction:

Paratesticular sarcoma are extremely rare malignant tumours. Unlike other sites, they tend to be lower grade and have higher propensity of lymphatic spread. They tend to fail locally and occasionally in the regional lymph nodes. In the absence of target volume delineation guidelines and technical illustration of conformal planning, we have made an attempt to illustrate conformal planning methodology and define target volume based on current evidence in a case of paratesticular sarcoma.

Methods:

We are presenting a case of 62-year-old male who presented with 15-cm scrotal swelling and underwent high inguinal orchidectomy with ligation of spermatic cord. Histopathology presented a well-differentiated leiomyosarcoma of epididymis. Post-operative radiotherapy target volume included the tumour bed, ipsilateral inguinal nodes and lower pelvic nodes as the clinical target volume.

Conclusion:

Adjuvant radiotherapy using advanced delivery technique such as volumetric arc technique can provide good dose distribution with good sparing of organs at risk. The downside of conformal radiation delivery is that it is a resource-intensive and has no established target volume delineation guidelines.

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.

Soft tissue tumours of the elbow: current concepts

Soft tissue tumours of the elbow are mostly benign. Malignant tumours in this area, although uncommon, often present unique clinical and histopathological characteristics that are helpful for diagnosis.Management of soft tissue tumours around the elbow may be challenging because of their rarity and the proximity to neurovascular structures. Careful staging, histological diagnosis and treatment are essential to optimize clinical outcome. A missed or delayed diagnosis or an improperly executed biopsy may have devastating consequences for the patient.This article reviews the most common benign and malignant soft tissue tumours of the elbow and discusses the clinicopathological findings, imaging features and current therapeutic concepts. Cite this article: EFORT Open Rev 2019;4:668-677. DOI: 10.1302/2058-5241.4.190002.

The genomics of undifferentiated sarcoma of soft tissue: Progress, challenges and opportunities

Undifferentiated sarcoma of soft tissue (USTS) are aggressive sarcomas that remain a diagnosis of exclusion and show extreme genomic complexity. Many advances in diagnostic criteria have resulted in several revisions in the definition of this rare cancer type. Recent sequencing efforts have illuminated the nature of the genome complexity and have revealed extensive copy number heterogeneity and multiple evolutionary patterns of development. This review places these recent advances into their historical and translational context and covers the changes in nomenclature, molecular classification, and the promise of personalised medicine.

Analysis of bone and soft-tissue sarcomas registered during the year 2012 at Tata Memorial Hospital, Mumbai, with clinical outcomes

Introduction

Primary bone and soft tissue sarcomas are rare, but diagnostically and therapeutically challenging group of tumors, requiring multidisciplinary management. There are limited documented studies from multidisciplinary teams , in the form of comprehensive analysis of these tumors, from our country. This study is an analysis of cases of osteosarcomas, Ewing sarcomas (ESs), chondrosarcomas (CSs), and soft-tissue sarcomas (STSs), registered at our institution during 2012.

Methods

Clinical details, including outcomes of cases of bone and STSs, during the year 2012, were retrieved from the medical records of our institution and were further analyzed.

Results

Ninety-five high-grade, extremity-based, treatment-naïve cases of osteosarcomas were treated with a novel, dose-dense, nonhigh-dose methotrexate-based OGS-12 protocol. Good histopathologic response (necrosis ≥90%) was achieved in 59% nonmetastatic and 56% metastatic patients. At a median follow-up of 48 months, the estimated 5-year event-free survival and overall survival (OS) were 67% and 78%, respectively. In the metastatic cohort at a median follow-up of 51 months, the 5-year estimated progression-free survival was 24% and OS was 26%. Among 87 (73.2%) nonmetastatic and 32 (26.8%) metastatic, analyzable cases of ES, at a median follow-up of 40 months, the disease-free survival (DFS) and OS in the nonmetastatic group were 62% and 83%; in the metastatic group, they were 37.5% and 65.6%, respectively. Among 40 cases of CSs (33 nonmetastatic and 7 metastatic), 21 had limb salvage surgery while 5 had amputation. Microscopically, 90.4% were Grade II CSs. Five-year OS and DFS were 84.6% and 71%, respectively. Among 189 high-grade, extremity-based STSs (89% nonmetastatic), synovial sarcoma was the most common subtype (31%). Eighty-five percent had limb preservation surgery; a majority were offered adjuvant radiation with or without chemotherapy. At a median follow-up of 51 (1-63) months, 3-year local control, DFS, and OS were 81%, 48%, and 64%, respectively.

Conclusions

The novel OGS 12 and Ewing Family of Tumors 2001 protocols have shown comparable outcomes to international standards in cases of osteosarcoma and ES, respectively, and merit wider applications, especially in low- and middle-income countries (LMICs). Outcomes in STS and CSs were also comparable and underscore the importance of a multidisciplinary approach for the management of sarcomas in LMICS.

Phase II study of neoadjuvant checkpoint blockade in patients with surgically resectable undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma

BACKGROUND

Soft tissue sarcomas are a heterogeneous and rare group of solid tumors of mesenchymal origin that can arise anywhere in the body. Although surgical resection is the mainstay of treatment for patients with localized disease, disease recurrence is common and 5-year overall survival is poor (~ 65%). Both radiation therapy and conventional chemotherapy are used to reduce local and distant recurrence. However, the utility of radiation therapy is often limited by disease location (in the case of retroperitoneal sarcomas, for instance) while systemic therapy with conventional lines of chemotherapy offer limited efficacy and are often poorly tolerated and associated with significant toxicity. Within the past decade, major advances have been made in the treatment of other malignancies including melanoma, renal cell carcinoma, and non-small cell lung carcinoma with the advent of immune-checkpoint inhibitors such as ipilimumab (anti-CTLA4), pembrolizumab (anti-PD1), and nivolumab (anti-PD1). The recently published SARC028 (NCT02301039), an open label, phase II, multicenter trial of pembrolizumab in patients with advanced bone and soft tissue sarcomas reported promising activity in select histologic subtypes of advanced STS, including undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma.

METHODS

There is a clear need for novel and effective adjuncts in the treatment of STS. We hypothesize that immune checkpoint blockade will be effective in patients with surgically resectable primary or locally recurrent dedifferentiated liposarcoma and undifferentiated pleomorphic sarcoma when administered in the neoadjuvant setting. The primary aim of this phase II, single-center, open label, randomized non-comparative trial is to determine the pathologic response to neoadjuvant nivolumab monotherapy and combination nivolumab/ipilimumab in patients with resectable dedifferentiated liposarcoma of the retroperitoneum or undifferentiated pleomorphic sarcoma of the trunk or extremity treated with concurrent standard of care neoadjuvant radiation therapy.

DISCUSSION

This study will help define the role of single agent anti-PD1 and combination anti-CTLA4 and anti-PD1 therapy in patients with surgically resectable dedifferentiated liposarcoma and undifferentiated pleomorphic sarcoma.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03307616 , registered October 12, 2017.

A matched cohort study of radio-chemotherapy versus radiotherapy alone in soft tissue sarcoma patients

PURPOSE

Adjuvant radiotherapy is the standard postoperative treatment after conservative surgery in high risk soft tissue sarcoma. The role of adjuvant chemotherapy is still debated. Therefore, a matched cohort analysis was performed in high risk soft tissue patients to analyse differences in terms of clinical outcome and toxicity between patients treated with concomitant radio-chemotherapy (RTCT) and radiotherapy (RT) alone.

MATERIALS AND METHODS

For each patient in RT group was selected a patient in the RTCT group matching for age, T stage and grading. Acute and late toxicity were recorded, overall survival, recurrence free survival and distant metastases free survival were analysed and compared between the two groups.

RESULTS

Ninety patients were selected, half of patients underwent radio-chemotherapy and half received radiotherapy alone. During the treatment Grade 3 dermatitis was recorded in 15 (16.7%) patients, 6 (6.7%) patients associated chemotherapy and during follow up 12 (13.3%) patients developed grade 2 late fibrosis, 3 (3.3%) joint stiffness and 1 (1.1%) patient experienced a bone fracture. There were no differences in the rate of acute and late toxicity between RTCT and RT alone group. Nineteen (21.1%) patients developed local recurrence, overall 5-year local relapse free survival was 83%. There were no differences between the two groups. 29 patients developed distant metastases, 14 (15.6%) patients in the RTCT group and 15 (16.7%) patients in the RT group. The 5-year distant metastases free survival was 67%. Age > 65 years was the only independent factor affecting distant recurrence (HR = 5.7, 95% CI 2.7-11.9; p = 0.001). At the time of analysis 15 (16.7%) patients were dead, 6 (6.7%) patients in the RTCT group and 9 (10%) patients in the RT group. 5-years overall survival was: 88%. At multivariate analysis age > 65 years was an independent prognostic factor of overall survival (HR = 3.7, 95% CI 1.2-12.1, p = 0.037).

CONCLUSIONS

Prospective randomized studies with large size population and with subgroup analysis for histological subtypes are necessary to clarify the role of adjuvant chemotherapy in soft tissue sarcoma patients. Tailored treatment has to be considered in elderly soft tissue patients to guarantee a better outcome in this high risk and fragile population.

Rhabdomyosarcoma of the breast: Report of a rare malignancy

Rhabdomyosarcoma (RMS) is an uncommon type of soft-tissue malignancy which mainly influences children. RMS rarely occurs in breast and little of the clinical behavior and treatment strategies were reported. Here, we describe a case of adult female patient with breast RMS. A 34-years-old Chinese woman visited to our hospital complaining palpable mass in her left breast. Seven months ago, the patient was diagnosed as lymphocytic mastitis and received surgical excision in the left breast. Five months later, she noticed a palpable mass again in the left breast. Ultrasonography suspected a malignant lesion and a diagnosis of RMS was made after segmental mastectomy and immunohistochemical staining. Therapy consisted of mastectomy and following neoadjuvant chemotherapy. The patient has remained disease free 30 months post-operatively. We should consider RMS when we see a breast mass. Tissue biopsy and immunohistochemical staining are recommended for diagnosis of RMS in young women. Oncologists should take immediate and active treatment on RMS.

Adequate Local Control in High-Risk Soft Tissue Sarcoma of the Extremity Treated with Surgery Alone at a Reference Centre: Should Radiotherapy Still be a Standard?

BACKGROUND

Established practice for the management of soft tissue sarcoma (STS) of the extremity and trunk wall combines perioperative radiotherapy (RT) with limb-preserving surgery.

OBJECTIVE

The aim of this study was to explore whether high-quality surgery at high-volume centers may offer equivalent local control in selected cases, when RT needs to be avoided.

METHODS

All consecutive adult cases of primary, high-risk STSs treated in a high-volume reference center over a 12-year timeframe were included, and, on retrospective analysis, were divided into two groups. Group A received RT with surgery, and Group B received surgery alone. The primary endpoint was local recurrence-free survival (LRFS).

RESULTS

Overall, 390 patients were included (318 in Group A and 72 in Group B), with a median follow-up of 53 months. The main reasons for avoiding RT were patient choice and technical considerations (vascular bypass or flap reconstruction). No difference in R0 resection was seen between the groups (79% vs. 70%; p = 0.18), but Group A had more G3 tumors (80.5% vs. 68%; p = 0.021). No difference in 5-year LRFS was evident (84% vs. 81%; p = 0.16).

CONCLUSIONS

LRFS did not differ between patients with high-risk STSs receiving perioperative RT and those treated with surgery alone. The study was retrospective and omission of RT was largely uncontrolled with inherent bias. Nonetheless, data suggest that in experienced centers, the omission of RT did not diminish local disease outcome. Future studies on a selective approach to RT administration are awaited.

Identification of predictors for wound complications following preoperative or postoperative radiotherapy in extremity soft tissue sarcoma

INTRODUCTION

In extremity soft tissue sarcoma (ESTS), external beam radiotherapy (EBRT) has been used in addition to limb-sparing surgery (LSS). This study aims to identify predictors for major wound complication (MWC) development following EBRT and LSS in ESTS.

METHODS

This retrospective study includes ESTS patients treated with EBRT and LSS between 2005 and 2017. Two groups were formed; Group I included preoperatively irradiated patients, whereas Group II included patients who underwent postoperative EBRT. Multivariate logistic regression analyses were performed to create a prediction model for MWC development.

RESULTS

One hundred twenty-seven patients were included, 58 patients (45.7%) in Group I and 69 patients (54.3%) in Group II. Some differences in baseline characteristics were found between the groups, e.g. in tumor size and grade, histological subtype and total RT dose. Twenty-three patients (39.7%) in Group I and 14 patients (20.3%) in Group II developed a MWC (p = 0.02). Preoperative EBRT was identified as independent predictor for MWC development, OR 2.75 (95%CI 1.21-6.26), p = 0.02. Furthermore, a trend towards an increased MWC risk was shown for patients' age (OR 1.02 (0.99-1.04)), delayed wound closure (OR 3.20 (0.64-16.02)) and negative surgical margins (OR 2.26 (0.72-7.11)). The area under the curve (AUC) of the model was 0.68 (0.57-0.79).

CONCLUSIONS

This study corroborates the increased MWC risk following preoperative EBRT in ESTS. It remains important to carefully weigh the MWC risk against the expected long-term functional outcome, and to consider the liberal use of primary plastic surgical reconstructions in an individualized multidisciplinary tumor board prior to treatment.

Analysis of the immune infiltrate in undifferentiated pleomorphic sarcoma of the extremity and trunk in response to radiotherapy: Rationale for combination neoadjuvant immune checkpoint inhibition and radiotherapy

Background: Undifferentiated pleomorphic sarcoma of the extremity and trunk (ET-UPS) presents a unique therapeutic challenge. Although immunotherapy has recently been employed in advanced soft tissue sarcoma, there is limited data characterizing the immune infiltrate in ET-UPS. Radiotherapy (RT) has been shown in other tumor types to promote tumor antigen release and enhance tumor-specific targeting by the adaptive immune system. The aim of this study was to 1) characterize the baseline immune infiltrate and 2) evaluate the effect of preoperative RT on the histologic appearance of and the immune infiltrate in ET-UPS. Methods: We identified 17 matched ET-UPS samples before and after RT. Immunohistochemistry was performed with CD8, CD4, PD-L1, PD1, CD3, CD163 and FoxP3 positive cells identified in all samples. Changes in the immune infiltrate following RT were examined. Results: There was a trend towards increased density of tumor infiltrating immune cells in ET-UPS following RT, with increases in median number of CD3 (158 vs 219 cells/mm2, p = 0.06), CD4 (3 vs 13 cells/mm2, p = 0.01), CD8 (55 vs 111 cells/mm2, p = 0.17), and FOXP3 (14 vs 25 cells/mm2, p = 0.23) positive cells. Interestingly, although PD-L1 was not expressed in any ET-UPS tumor at baseline, positive PD-L1 expression was observed in 21% (3/14) of tumors after RT (p = 0.07). Conclusion: An immune infiltrate is present in ET-UPS at the time of diagnosis, with a trend towards increased density of immune infiltrate and PD-L1 expression after RT. These data support prospectively evaluating immune checkpoint inhibitors with standard of care RT in the treatment of ET-UPS.

Chronic radiation-induced dermatitis: challenges and solutions

Chronic radiation dermatitis is a late side effect of skin irradiation, which may deteriorate patients’ quality of life. There is a lack of precise data about its incidence; however, several risk factors may predispose to the development of this condition. It includes radiotherapy dose, fractionation, technique, concurrent systemic therapy, comorbidities, and personal and genetic factors. Chronic radiation dermatitis is mostly caused by the imbalance of proinflammatory and profibrotic cytokines. Clinical manifestation includes changes in skin appearance, wounds, ulcerations, necrosis, fibrosis, and secondary cancers. The most severe complication of irradiation is extensive radiation-induced fibrosis (RIF). RIF can manifest in many ways, such as skin induration and retraction, lymphedema or restriction of joint motion. Diagnosis of chronic radiation dermatitis is usually made by clinical examination. In case of unclear clinical manifestation, a biopsy and histopathological examination are recommended to exclude secondary malignancy. The most effective prophylaxis of chronic radiation dermatitis is the use of proper radiation therapy techniques to avoid unnecessary irradiation of healthy skin. Treatment of chronic radiation dermatitis is demanding. The majority of the interventions are based only on clinical practice. Telangiectasia may be treated with pulse dye laser therapy. Chronic postirradiation wounds need special dressings. In case of necrosis or severe ulceration, surgical intervention may be considered. Management of RIF should be complex. Available methods are rehabilitative care, pharmacotherapy, hyperbaric oxygen therapy, and laser therapy. Future challenges include the assessment of late skin toxicity in modern irradiation techniques. Special attention should be paid on genomics and radiomics that allow scientists and clinicians to select patients who are at risk of the development of chronic radiation dermatitis. Novel treatment methods and clinical trials are strongly needed to provide more efficacious therapies.