Synovial sarcoma: characteristics, challenges, and evolving therapeutic strategies.

Synovial sarcoma (SS) is a rare and aggressive disease that accounts for 5%-10% of all soft tissue sarcomas. Although it can occur at any age, it typically affects younger adults and children, with a peak incidence in the fourth decade of life. In >95% of cases, the oncogenic driver is a translocation between chromosomes X and 18 that leads to the formation of the SS18::SSX fusion oncogenes. Early and accurate diagnosis is often a challenge; optimal outcomes are achieved by referral to a specialist center for diagnosis and management by a multidisciplinary team as soon as SS is suspected. Surgery with or without radiotherapy and/or chemotherapy can be effective in localized disease, especially in children. However, the prognosis in the advanced stages is poor, with treatment strategies that have relied heavily on traditional cytotoxic chemotherapies. Therefore, there is an unmet need for novel effective management strategies for advanced disease. An improved understanding of disease pathology and its molecular basis has paved the way for novel targeted agents and immunotherapies that are being investigated in clinical trials. This review provides an overview of the epidemiology and characteristics of SS in children and adults, as well as the patient journey from diagnosis to treatment. Current and future management strategies, focusing particularly on the potential of immunotherapies to improve clinical outcomes, are also summarized.

SELNET clinical practice guidelines for bone sarcoma.

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context.

Systemic treatment in advanced phyllodes tumor of the breast: a multi-institutional European retrospective case-series analyses.

BACKGROUND: We aimed at investigating outcome of systemic treatments in advanced breast PT. METHODS: All cases of advanced breast PT treated with systemic treatments from 1999 to 2019, in one of the referral sarcoma centers involved in the study, were retrospectively reviewed. RESULTS: 56 female patients were identified. Median age was 52 (range of 25-76) years. Patients received a median number of 2 systemic treatments (range of 1-4). Best responses according to RECIST were 1 (3.7%) CR, 11 (40.7%) PR, 6 (22.2%) SD, 9 (33.3%) PD with anthracyclines plus ifosfamide (AI); 2 (16.7%) PR, 4 (33.3%) SD, 6 (50.0%) PD with anthracycline alone; 3 (18.8%) PR, 4 (25.0%) SD, 9 (56.3%) PD with high-dose ifosfamide given as a continuous infusion (HD-IFX); 3 (20.0%) SD, 12 (80.0%) PD with a gemcitabine-based regimen (with 2 patients not evaluable); 1 (8.3%) PR, 2 (16.7%) SD, 9 (75.0%) PD with trabectedin (with 1 patient not evaluable); 1 (16.7%) PR, 1 (16.7%) SD, 4 (66.7%) PD with tyrosine-kinase inhibitors (TKI). The median PFS were 5.7 (IQR 2.5-9.1) months with AI; 3.2 (IQR 2.2-5.0) months with anthracycline alone; 3.4 (IQR 1.4-6.7) months with HD-IFX; 2.1 (IQR 1.4-5.2) months with gemcitabine-based chemotherapy; 1.8 (IQR 0.7-6.6) months with trabectedin; 3.4 (IQR 3.1-3.8) months with TKI. With a median follow-up of 35.3 (IQR 17.6-66.9) months, OS from the start of first-line systemic treatment was 15.2 (IQR 7.6-39.6) months. CONCLUSION: In this series of advanced PT (to our knowledge, the largest reported so far), AI was associated with a high rate of responses, however, with a median PFS of 5.7 months. Other systemic treatments were poorly active.

Intratumor morphologic and transcriptomic heterogeneity in V600EBRAF-mutated metastatic colorectal adenocarcinomas.

BACKGROUND: Intratumor heterogeneity (ITH) is described as the presence of various clones within one tumor, each with their own unique features in terms of morphology, inflammation, genetics or transcriptomics. Heterogeneity provides the fuel for drug resistance; therefore, an accurate assessment of tumor heterogeneity is essential for the development of effective therapies. The purpose of this study was to dissect morphologic and molecular ITH in colorectal adenocarcinoma. MATERIALS AND METHODS: A series of 120 V600EBRAF-mutated (V600EBRAFmt) consecutive metastatic colorectal adenocarcinomas was assessed for morphologic heterogeneity. The two heterogeneous components of each specimen underwent a histopathological, immunohistochemical and molecular characterization to evaluate: histologic variant, grading, tumor-infiltrating lymphocytes (TILs), mismatch repair proteins' expression, KRAS/BRAF/NRAS mutations, microsatellite instability (MSI) status and consensus molecular subtype (CMS). RESULTS: Thirty-one out of 120 (25.8%) V600EBRAFmt primary colorectal adenocarcinomas presented a heterogeneous morphology. Among these, eight cases had adequate material for molecular profiling. Five out of the eight (62.5%) cases resulted instable at MSI testing. The majority (62.5%) of the samples showed a CMS4 phenotype based on gene expression profiling. Heterogeneity in CMS classification was observed in four out of eight cases. One out of eight cases presented significant heterogeneity in the number of TILs between the two components of the tumor. CONCLUSIONS: Although the distribution of the immune infiltrate appears relatively conserved among heterogeneous areas of the same tumor, changes in gene expression profile and CMS occur in 50% of V600EBRAFmt adenocarcinoma cases in our small series and might contribute to variability in response to anticancer therapy and clinical outcomes. Assessment of morphological and molecular ITH is needed to improve colorectal cancer classification and to tailor anticancer treatments and should be included in the pathology report.

Druggable targets meet oncogenic drivers: opportunities and limitations of target-based classification of tumors and the role of Molecular Tumor Boards.

The therapeutic landscape of cancer is changing rapidly due to the growing number of approved drugs capable of targeting specific genetic alterations. This aspect, together with the development of noninvasive methods for the assessment of somatic mutations in the peripheral blood of patients, generated a growing interest toward a new tumor-agnostic classification system based on 'predictive' biomarkers. The current review article discusses this emerging alternative approach to the classification of cancer and its implications for the selection of treatments. It is suggested that different types of cancers sharing the same molecular profiles could benefit from the same targeted drugs. Although recent clinical trials have demonstrated that this approach cannot be generalized, there are also specific examples that demonstrate the clinical utility of this alternative vision. In this rapidly evolving scenario, a multidisciplinary approach managed by institutional Molecular Tumor Boards is fundamental to interpret the biological and clinical relevance of genetic alterations and the complexity of their relationship with treatment response.

Diagnosis and management of tropomyosin receptor kinase (TRK) fusion sarcomas: expert recommendations from the World Sarcoma Network.

Sarcomas are a heterogeneous group of malignancies with mesenchymal lineage differentiation. The discovery of neurotrophic tyrosine receptor kinase (NTRK) gene fusions as tissue-agnostic oncogenic drivers has led to new personalized therapies for a subset of patients with sarcoma in the form of tropomyosin receptor kinase (TRK) inhibitors. NTRK gene rearrangements and fusion transcripts can be detected with different molecular pathology techniques, while TRK protein expression can be demonstrated with immunohistochemistry. The rarity and diagnostic complexity of NTRK gene fusions raise a number of questions and challenges for clinicians. To address these challenges, the World Sarcoma Network convened two meetings of expert adult oncologists and pathologists and subsequently developed this article to provide practical guidance on the management of patients with sarcoma harboring NTRK gene fusions. We propose a diagnostic strategy that considers disease stage and histologic and molecular subtypes to facilitate routine testing for TRK expression and subsequent testing for NTRK gene fusions.

The sacral chordoma margin.

OBJECTIVE: Aim of the manuscript is to discuss how to improve margins in sacral chordoma. BACKGROUND: Chordoma is a rare neoplasm, arising in half cases from the sacrum, with reported local failure in >50% after surgery. METHODS: A multidisciplinary meeting of the "Chordoma Global Consensus Group" was held in Milan in 2017, focusing on challenges in defining and achieving optimal margins in chordoma with respect to surgery, definitive particle radiation therapy (RT) and medical therapies. This review aims to report on the outcome of the consensus meeting and to provide a summary of the most recent evidence in this field. Possible new ways forward, including on-going international clinical studies, are discussed. RESULTS: En-bloc tumor-sacrum resection is the cornerstone of treatment of primary sacral chordoma, aiming to achieve negative microscopic margins. Radical definitive particle therapy seems to offer a similar outcome compared to surgery, although confirmation in comparative trials is lacking; besides there is still a certain degree of technical variability across institutions, corresponding to different fields of treatment and different tumor coverage. To address some of these questions, a prospective, randomized international study comparing surgery versus definitive high-dose RT is ongoing. Available data do not support the routine use of any medical therapy as (neo)adjuvant/cytoreductive treatment. CONCLUSION: Given the significant influence of margins status on local control in patients with primary localized sacral chordoma, the clear definition of adequate margins and a standard local approach across institutions for both surgery and particle RT is vital for improving the management of these patients.

Extra-axial chordoma: a clinicopathologic analysis of six cases.

Extra-axial chordoma is an exceedingly rare tumor, with only 28 cases reported in the literature to date. Axial and extra-axial chordoma exhibits complete morphologic and immunophenotypic (expression of brachyury) overlap. However, in consideration of the non-canonical presentation, extra-axial chordoma is under-recognized and often misdiagnosed, most often as extraskeletal myxoid chondrosarcoma or myoepithelioma. To increase our understanding of the clinicopathologic features of extra-axial chordoma, six cases have been retrieved from the files of the Istituto Ortopedico Rizzoli and of the General Hospital of Treviso. The clinicoradiologic, morphologic, and molecular features have been analyzed, and the follow-up was updated. Our series included four female and two male patients; their ages ranged from 20 to 67 years (mean 45.8 years). All patients presented with a single mass localized in four cases in the soft tissue (posterior arm, left leg, dorsal aspect of the foot, and popliteal fossa), and in two cases in the bone (radius and second metacarpal bone). Grossly, the neoplasm was lobulated, with a fleshy cut surface and a diameter ranging between 0.8 and 8 cm (mean 3.4 cm). Morphologically, all six cases showed an epithelioid cell proliferation organized in nests and cords demarcated by fibrous septa and set in an abundant extracellular myxoid matrix. Neoplastic cells featured hyperchromatic nuclei and abundant vacuolated cytoplasm. Immunohistochemically, all six cases were strongly positive for EMA, cytokeratin AE1/AE3, S100, and brachyury. INI1 nuclear expression was retained. Smooth muscle actin, calponin, p63, and GFAP were all negative. Fluorescent in situ hybridization (FISH) analysis did not reveal rearrangements involving NR4A3, FUS, and EWSR1 genes. At follow-up (mean 55 months), all patients were alive without disease after local surgical treatment. One patient underwent thigh amputation following multiple local recurrences and inguinal node metastases treated with marginal resection. In conclusion, primary extra-axial chordoma is an extremely rare neoplasm with distinct morphological and immunohistochemical features. Immunomorphology and molecular analysis allow distinction from both extraskeletal myxoid chondrosarcoma and myoepithelioma. Complete surgical resection appears to be curative.

Histology and grading are important prognostic factors in synovial sarcoma.

INTRODUCTION: The diagnosis of synovial sarcoma (SS) is currently based on clinical, morphological, immunohistochemical and cytogenetic data. Some of these factors such as grade and histology, specific translocations (SS18-SSX1 vs. SS18-SSX2) and the reduced expression of INI1, were proposed as prognostic variables. The aim of this study was to verify whether histological (grading and histology) and molecular (type of SSX translocation and INI1 expression) characteristics of SS influence the prognosis of the disease. MATERIAL AND METHODS: We retrospectively evaluated 196 patients affected by SS of the extremities treated at our Institution (Istituto Ortopedico Rizzoli, Bologna, Italy). All cases were histologically revised and tumor grade was assessed according to the FNLCC system. Tissue specimens were retrospectively evaluated to check for SS18-SSX fusion type and INI1 expression. RESULTS: Most SS were monophasic, 28% were biphasic. Eighty tumors (41%) were grade 3. Sixty percent harbored SSX1 translocation, 40% SSX2; 51% maintained the expression of INI1. Sarcoma specific survival (OS) was 56.6% at 5 years and 46.9% at 10 years. Prognosis was worse in those patients monophasic SS (p = 0.011) as in those with a grade 3 tumors (p = 0.083). No correlation was found neither between SSX fusion type nor INI1 expression and survival. LR-free survival was 78.9% at 5 years and 75.9% at 10 years. A higher LR rate was observed in tumors with SSX2 translocation and (p = 0.049) in grade 3 SS (0 = 0.028). DISCUSSION: Our data confirm that not all cases of SS present the same severe outcome. High-risk patients identified on the basis of these parameters may qualify for an aggressive treatment approach.