Sarcoma: concordance between initial diagnosis and centralized expert review in a population-based study within three European regions

Revolutionising osseous biopsy: the impact of artificial intelligence in the era of personalized medicine

In a rapidly evolving healthcare environment, artificial intelligence (AI) is transforming diagnostic techniques and personalized medicine. This is also seen in osseous biopsies. AI applications in radiomics, histopathology, predictive modelling, biopsy navigation, and interdisciplinary communication are reshaping how bone biopsies are conducted and interpreted. We provide a brief review of AI in image- guided biopsy of bone tumours (primary and secondary) and specimen handling, in the era of personalized medicine. This article explores AI's role in enhancing diagnostic accuracy, improving safety in biopsies, and enabling more precise targeting in bone lesion biopsies, ultimately contributing to better patient outcomes in personalized medicine. We dive into various AI technologies applied to osseous biopsies, such as traditional machine learning, deep learning, radiomics, simulation, and generative models. We explore their roles in tumour-board meetings, communication between clinicians, radiologists, and pathologists. Additionally, we inspect ethical considerations associated with the integration of AI in bone biopsy procedures, technical limitations, and we delve into health equity, generalizability, deployment issues, and reimbursement challenges in AI-powered healthcare. Finally, we explore potential future developments and offer a list of open-source AI tools and algorithms relevant to bone biopsies, which we include to encourage further discussion and research.

Superiority of targeted RNA sequencing for fusion detection and subtype diagnosis in Chinese sarcoma patients: a multicenter study

Sarcomas are rare, heterogeneous mesenchymal malignancies with notably high misdiagnosis rates. Despite sarcoma patients in China representing about one-quarter of the global disease burden, large-scale NGS-based diagnostic studies remain scarce, with limited sample sizes failing to capture the extensive subtype complexity of sarcomas. To address diagnostic gaps, we conducted the largest multicenter study in China involving 788 patients with soft tissue or bone sarcomas. All samples underwent targeted RNA sequencing (Fusioncapture) alongside standard histopathology, immunohistochemistry, and DNA-based next-generation sequencing (NGS). Compared with DNA-NGS, RNA-based profiling clarified ambiguous fusion calls and uncovered numerous additional and clinically relevant events, including 281 fusions not captured by the DNA panel. Notably, 114 recurrent alterations were strongly subtype-associated, and 20 newly identified receptor tyrosine kinase fusions had therapeutic significance, expanding targetable cases from 3.3% to 6.5%. Furthermore, integrated RNA data led to subtype reclassification in 11.9% of patients, including 22% of those initially diagnosed as "not otherwise specified". These findings confirm the utility of targeted RNA sequencing for detecting transcriptionally active fusions, refining pathological classifications, and identifying actionable variants in Chinese sarcoma patients. Despite retrospective design and limited orthogonal validation of some fusions, our results strongly support incorporating RNA-based assays into routine clinical workflows. Ultimately, this integrated approach can improve diagnostic precision, guide personalized treatment strategies, and enhance outcomes for sarcoma patients.

Approaches to Ultra-Rare Sarcomas: Definitions, Diagnostics, and Therapies

Ultra-rare sarcomas are sarcomas with an incidence of 1 case per million inhabitants per year, in which rarity poses a barrier to conducting histotype-specific randomized studies. This manuscript provides practical information and reference for clinicians and researchers looking to develop an understanding of the complexity, worldwide discrepancies in treatment options, and management choices for these patients. We provide definitions, diagnostic challenges, and therapeutic approaches to ultra-rare sarcomas. We highlight existing discriminations faced by patients with ultra-rare sarcoma, differences in approval status for innovative agents, and future perspectives for sarcoma experts who aim at working for a change in the field.

Landscape of ultra-rare sarcomas: a nationwide study for epidemiology and prognosis

BACKGROUND

The concept of 'ultra-rare sarcoma' was established to raise awareness of the clinical challenges resulting from its rarity. Given the novelty of this classification and the consequent paucity of data, this study aimed to investigate the epidemiology and prognosis of ultra-rare sarcomas.

DESIGN

We analyzed data from the Bone and Soft Tissue Tumor Registry in Japan from 2001 to 2019, comparing ultra-rare and non-ultra-rare sarcomas. To assess the prognostic impact of ultra-rare sarcomas, we used Kaplan-Meier survival analysis with propensity score matching, multivariate analysis, and a machine learning technique known as random survival forest.

RESULTS

Among the 22 821 patients analyzed, ultra-rare sarcomas accounted for 18.9% of the cases. Ultra-rare bone sarcomas were older than non-ultra-rare bone sarcomas (mean age: 57.6 versus 39.2 years, P < 0.001), while ultra-rare soft tissue sarcomas appeared in younger patients (mean age: 49.4 versus 62.2 years, P < 0.001). For patients >80 years old with bone sarcomas and those <20 years old with soft tissue sarcomas, ultra-rare sarcomas constituted approximately half of the cases. Survival analysis indicated that ultra-rare bone sarcomas were associated with longer survival (P = 0.022), whereas ultra-rare soft tissue sarcomas showed no significant difference in overall survival (P = 0.052). When stratified by age, however, patients <40 years old with ultra-rare soft tissue sarcomas had shorter survival (P < 0.001). Multivariate analysis indicated hazard ratios of 0.73 for ultra-rare bone and 1.25 for ultra-rare soft tissue sarcomas. Random survival forest showed that the importance of ultra-rare sarcomas was relatively low compared with other parameters.

CONCLUSION

Ultra-rare sarcomas are more common among older bone sarcoma patients and younger soft tissue sarcoma patients. Young patients with ultra-rare soft tissue sarcomas have a significantly worse prognosis. Overall, while ultra-rare sarcomas have a generally minor impact on prognosis, their effects are more pronounced in specific age groups.

ASO Practice Guidelines Series: Multidisciplinary Management of Retroperitoneal Sarcomas

Retroperitoneal sarcomas (RPS) represent a rare and biologically diverse group of malignancies, distinct from soft tissue sarcomas arising in other anatomic regions. Their deep-seated location, large size at presentation and proximity to critical structures contribute to diagnostic delays, treatment challenges, and variable oncologic outcomes, particularly when managed outside high-volume referral centers. Current international guidelines emphasize the importance of preoperative biopsy, review by a sarcoma pathologist, management in a referral center, multidisciplinary case discussion, consideration for clinical trials enrollment, and prospective database inclusion as standards of care. Given that the quality of the initial surgical resection-achieving complete macroscopic resection with margins tailored to the histologic type-remains the most important modifiable prognostic factor, adherence to international best practices in surgical and multimodal treatment is crucial to optimize patient outcomes. This article reviews contemporary management strategies for adult-type RPS, emphasizing the importance of multidisciplinary expertise.

Enhancing precision in sarcoma diagnosis: nCounter fusion panel implementation in a middle-income country

Background

Sarcoma diagnosis is challenging due to numerous subtypes with similar histopathological features and the high cost of fusion detection methods, particularly in middle-income countries.

Objectives

To implement a cost-effective custom-based nCounter approach previously validated for fusion analysis of suspected sarcoma in Brazil.

Design and methods

RNA isolated from 56 routine sarcomas, which were formalin-fixed and paraffin-embedded, was analyzed using a custom nCounter assay that detects 174 common sarcoma gene fusions. The results were compared to fluorescence in situ hybridization (FISH)/next-generation sequencing (NGS) and clinicopathological data.

Results

The nCounter assay was conclusive in 98.2% of cases, identifying 25 gene fusions with 82.5% accuracy, 76.6% sensitivity, and 100% specificity compared to FISH/NGS.

Conclusion

Although it does not identify all sarcoma fusions, especially for rare subtypes, the present nCounter assay is a rapid, affordable, and accurate tool for sarcoma diagnosis in resource-limited settings.

Clinician's primer for soft tissue sarcomas: Nuances of histologic subtypes

Soft tissue sarcomas are a rare group of mesenchymal malignancies, with greater than 100 histologic subtypes. Advancements in understanding these subtypes has enabled histology-tailored management. This primer describes the workup and management of generalized soft tissue sarcomas of the extremity, trunk, and retroperitoneum while also highlighting the unique attributes of many subtypes. The subtypes chosen for review include those that are most common as well as those demonstrating unique behaviors or targets for management. The focus is on initial management of localized disease; however, for situations in which novel systemic agents have been discovered, the treatment of metastatic disease is discussed. This report is a reference to be used in addition to other comprehensive reviews, such as guidelines from the National Comprehensive Cancer Network, the European Society for Medical Oncology, and the American Society for Radiation Oncology. It is not a substitute for referral to an expert sarcoma center for critical pathology review and management by an experienced team. Importantly, patients who are treated at expert sarcoma centers have better outcomes than those who are not.

Breaking barriers: The impact of telemedicine on improving soft tissue and bone tumor management in Armenia

PURPOSE

Musculoskeletal sarcomas are a rare group of malignant neoplasms, accounting for approximately 12 % of all malignant neoplasms among children. Childhood cancer outcomes vary between developed and developing countries due to financial and educational inequalities. Telemedicine programs have a huge impact on the quality of cancer care, helping to optimize resources for better cancer care in a resource-limited setting. In 2019, Armenia established multidisciplinary teams (MDT) with the guidance of international experts via telemedicine, significantly improving patients' management diagnosed with sarcomas.

METHODS

The musculoskeletal cancer working group, mentored by the University Hospital of Münster (UKM), conducted weekly virtual tumor boards to discuss cases, focusing on the review of pathological and radiological examinations.

RESULTS

From August 2019 to December 2023, the musculoskeletal cancer MDT discussed 151 musculoskeletal tumor cases via 74 MDT meetings. Imaging studies of all discussed cases were reviewed, while the review of histology images was performed for 93 % of cases. The pathology review led to changes in previously established diagnoses in eleven cases, which subsequently changed management. These led to altered local control strategies for 32 patients, with 5 requiring treatment abroad, and changes in chemotherapy regimens for 17 patients. Notably, there were no cases of treatment refusal post-implementation, a reduction from the previous 3 % refusal rate.

CONCLUSION

The successful telemedicine initiative, coupled with institutional support, improved the care of patients diagnosed with musculoskeletal tumors. The investment in telemedicine in developing countries not only enhances communications with international and local experts across various disciplines but also significantly improves the handling of patients diagnosed with sarcomas.

Underrecognized diagnostic discordance and delay in endometrial dedifferentiated and undifferentiated carcinoma

AIM

Dedifferentiated and undifferentiated endometrial carcinoma (DC/UC) is a rare subtype of endometrial cancer characterized by undifferentiated carcinoma components. This study aimed to investigate diagnostic discrepancies and delays in DC/UC and compare them with low-grade endometrioid carcinoma (LGEC).

METHODS

We retrospectively analyzed 20 DC/UC and 40 LGEC cases finally diagnosed at our hospital (2016-2024). We compared the data of the two groups, including clinicopathologic characteristics and diagnostic intervals defined as the time from the date of initial biopsy to the date of definitive diagnosis. We assessed diagnostic discordances between preoperative diagnoses, including radiological, clinical, and biopsy, and final diagnoses with immunohistochemical analyses.

RESULTS

DC/UC cases exhibited significantly longer diagnostic intervals (median 46 vs. 5 days, p = 0.037) and required more biopsy attempts (median two vs. 1, p = 0.002) and immunohistochemical tests (median 19 vs. 6, p = 0.001) than LGEC cases. In preoperative diagnoses, 60% of DC/UC cases showed diagnostic discrepancies. Radiological findings frequently suggested uterine sarcoma in DC/UC (30%, 6/20). Only 50% of DC/UC were suggested via initial biopsy. Immunohistochemistry revealed mismatch repair deficiency in 70% of DC/UC cases.

CONCLUSIONS

Frequent diagnostic discrepancies and delays were observed in DC/UC, possibly due to its atypical imaging and histopathological features. Raising awareness of DC/UC's clinical and pathological characteristics is crucial to minimizing diagnostic delays. Given its frequency (at least 1% of endometrial cancers) and eligibility for emerging therapies, prioritizing DC/UC in differential diagnoses and improving diagnostic workflows through interdisciplinary collaboration are required for timely and effective treatment.

Pain Accelerates, Swelling and Sensory Disturbances Delay Diagnosis in Mesenchymal Tumors

Sarcomas are rare mesenchymal tumors with significant heterogeneity, encompassing both bone and soft tissue neoplasms that can range from benign to malignant and from superficial to deep-seated lesions [...].

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. This makes it more important that STS are managed by expert multidisciplinary teams, to ensure consistent and optimal treatment, 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 versions published in 2010 and 2016 [1, 2]. The original guidelines were drawn up by a panel 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 iteration of the guidance, as well as updating the general multidisciplinary management of soft tissue sarcoma, includes specific sections relating to the management of sarcomas at defined anatomical sites: gynaecological sarcomas, retroperitoneal sarcomas, breast sarcomas, and skin sarcomas. These are generally managed collaboratively by site specific multidisciplinary teams linked to the regional sarcoma specialist team, as stipulated in the recently published sarcoma service specification [3]. In the UK, any patient with a suspected soft tissue sarcoma should be referred to a specialist regional soft tissues sarcoma service, to be managed by a specialist sarcoma multidisciplinary team. Once the diagnosis has been confirmed using appropriate imaging and a tissue biopsy, the main modality of management is usually surgical excision performed by a specialist surgeon, combined with pre- or post-operative radiotherapy for tumours at higher risk for local recurrence. Systemic anti-cancer therapy (SACT) may be utilised in 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.

Lymphadenectomy in the treatment of sarcomas - indications and technique

Sarcomas are a rare type of malignancy with limited treatment options so far. This analysis aimed to describe the impact of lymphadenectomy on treating sarcoma patients. Sarcomas characterized by lymphatic spread are rare. For this reason, lymphadenectomy is not a procedure that is performed frequently. However, there are histological subtypes that spread more frequently through lymphatic vessels, such as rhabdomyosarcoma (RMS), epithelioid sarcoma (ES), clear cell sarcoma (CCS), and angiosarcoma. On the other hand, synovial sarcoma (SS) is not characterized by an increased tendency to lymphogenous metastases. In our study, we focus on these subtypes of sarcomas. The relationship between lymphadenectomy results and the subsequent prognosis of the patients was investigated. Metastases in the lymph nodes are diagnosed synchronously with distant metastases or when the primary tumor is detected. At the same time, despite lymphadenectomy, sarcoma patients developed further distant metastases. Currently, lymphadenectomy is not a routinely recommended method of treatment for patients with sarcomas. Most often, its potential use is indicated in the case of epithelioid sarcoma, clear cell sarcoma, and rhabdomyosarcoma after a previous positive sentinel lymph node biopsy (SLNB) result. Multicenter randomized prospective clinical trials on the role of lymphadenectomy in the treatment of sarcomas are needed.

Intracranial pleomorphic liposarcoma misclassified as a pleomorphic xanthoastrocytoma by a DNA methylation classifier: illustrative case

BACKGROUND

Recently, it has been shown that DNA methylation arrays and German Cancer Research Center (Deutsches Krebsforschungszentrum) methylation classifiers are useful aids in brain tumor diagnosis for cases in which histopathological diagnosis is difficult. However, not enough is known about diagnostic aids for intracranial liposarcoma (LPS).

OBSERVATIONS

An 18-year-old woman with a history of natural killer/T-cell lymphoma, which had been treated with a bone marrow transplant and total body irradiation at age 11 years, presented with diplopia. Magnetic resonance imaging revealed a brain tumor in the posterior left temporal lobe, which was removed by craniotomy. The tumor was initially diagnosed as pleomorphic xanthoastrocytoma through histopathological and DNA methylation examination. She also had a soft tissue tumor in her left thigh, which was removed. It contained spindle cells with oval nuclei and highly pleomorphic cells and was diagnosed as radiation-induced LPS. Histopathological re-examination of the brain tumor led to a final diagnosis of pleomorphic LPS.

LESSONS

In this report, the authors describe the case of a patient with an intracranial pleomorphic LPS that was initially classified as a pleomorphic xanthoastrocytoma by a DNA methylation classifier. Although DNA methylation classifiers are useful as diagnostic aids in cases in which definitive pathology is difficult to determine, there is a risk of misdiagnosis in some types of tumors. https://thejns.org/doi/10.3171/CASE24465.

Biphenotypic sinonasal sarcoma diagnosed by detection of PAX3-MAML3 fusion gene using integrated whole-genome and transcriptome sequencing

Biphenotypic sinonasal sarcoma (BSNS) is a double-phenotype sarcoma that shows differentiation in both the nervous and muscular systems. To date, whole-genome and transcriptome sequencing (WGTS) has not been used to analyze BSNS. We report a patient with BSNS who was diagnosed based on PAX3 rearrangement using WGTS. A 71-year-old Japanese male without remarkable symptoms showed a nasal tumor when undergoing computed tomography. Although pathological examination revealed a non-characteristic spindle cell tumor, a definitive diagnosis could not be made based on this examination. Endoscopic sinus surgery was performed for subsequent diagnosis, treatment, and WGTS. WGTS revealed a t(2; 4)(q35; q31.1) reciprocal translocation, resulting in a PAX3-MAML3 fusion gene, leading to a definitive diagnosis of BSNS. We also detected upregulation of the expression of PAX3, MAML3, and 11 known genes involved in neural and myogenic differentiation relevant to the BSNS phenotype. Hence, using WGTS in combination with conventional pathological diagnosis can contribute to a definitive diagnosis of rare cancers, including BSNS, by detecting chromosomal rearrangements or diagnostic markers.

Primary Retrovesical Leiomyosarcoma: A Case Report

Soft tissue sarcomas (STS) are a rare group of malignant tumors in adults. This group of tumors contains a variety of subtypes, each with distinct clinical features and presentations. Leiomyosarcoma is among the most common subtypes, which typically occur within the uterus, retroperitoneum, abdomen, and large blood vessels. At presentation, tumors are often large and may have metastasized to the lungs, liver, or peritoneum. Given the rarity and variability of the disease, a multidisciplinary treatment approach is essential for management, however, further research is needed to develop histologic-specific guidelines and targeted treatments. Here, we present a case of a 69-year-old male who was found to have a large pelvic mass of unknown etiology after presenting to the emergency department with generalized weakness, decreased appetite, and an inability to ambulate. On examination, he was found to have testicular swelling and trace edema of bilateral lower extremities. Labs significant for lactic acidosis and CT chest/abdomen/pelvis showed a large heterogeneously enhancing mass within the pelvis measuring up to 15 cm x 12 cm x 15 cm, of uncertain origin, but highly concerning for malignancy. Biopsy with immunohistochemical stains of the mass revealed a grade 2 leiomyosarcoma. Due to the size and location of the mass, transfer to a tertiary care center was recommended. Computed tomography angiography (CTA) abdomen/pelvis and magnetic resonance imaging (MRI) abdomen/pelvis performed at the tertiary care hospital revealed a 16.6 cm heterogeneously enhancing, necrotic mass within the retrovesical pelvic space and three liver lesions, which were concerning for metastases. Due to the patient's deconditioning and poor functional status, surgical resection and radiation were not offered. The patient expired soon after his code status was changed to comfort care.

Clinical relevance and druggability of sole reciprocal kinase fusions: A large-scale study

BACKGROUND

Building on our prior work that RNA alternative splicing modulates the druggability of kinase fusions, this study probes the clinical significance of sole reciprocal fusions. These rare genomic arrangements, despite lacking kinase domains at the DNA level, demonstrated potential RNA-level druggability in sporadic cases from our prior research.

METHODS

Utilizing the large-scale multicenter approach, we performed RNA sequencing and clinical follow-up to evaluate a broad spectrum of kinase fusions, including ALK, ROS1, RET, BRAF, NTRK, MET, NRG1, and EGFR, in 1943 patients.

RESULTS

Our findings revealed 51 instances (2.57%) of sole reciprocal fusions, predominantly in lung (57%), colorectal (14%), and glioma (10%) cancers. Comparative analysis with an MSKCC cohort confirmed the prevalence in diverse cancer types and identified unique fusion partners and chromosomal locales. Cross-validation through RNA-NGS and FISH authenticated the existence of functional kinase domains in subsets including ALK, ROS1, RET, and BRAF, which correlated with positive clinical responses to targeted kinase inhibitors (KIs). Conversely, fusions involving EGFR, NRG1, and NTRK1/2/3 generated nonfunctional transcripts, suggesting the need for alternative therapeutic interventions.

CONCLUSION

This inaugural multicenter study introduces a novel algorithm for detecting and treating sole reciprocal fusions in advanced cancers, expanding the patient population potentially amenable to KIs.

Histological diagnostic discrepancy and its clinical impact in bone and soft tissue tumors referred to a sarcoma center

Histological diagnosis of sarcomas (malignant bone and soft tissue tumors) is challenging due to their rarity, morphological diversity, and constantly evolving diagnostic criteria. In this study, we aimed to assess the concordance in histological diagnosis of bone and soft tissue tumors between referring hospitals and a tertiary sarcoma center and analyzed the clinical impact of the diagnostic alteration. We analyzed 628 consecutively accessioned specimens from 624 patients who visited a specialized sarcoma center for treatment. The diagnoses at referring hospitals and those at the sarcoma center were compared and classified into four categories: agreed, disagreed, specified, and de-specified. Of the 628 specimens, the diagnoses agreed in 403 (64.2%) specimens, whereas some changes were made in 225 (35.8%) specimens: disagreed in 153 (24.3%), specified in 52 (8.3%), and de-specified in 20 (3.2%) cases. The benign/intermediate/malignant judgment changed for 92 cases (14.6%). The diagnostic change resulted in patient management modification in 91 cases (14.5%), including surgical and medical treatment changes. The main inferred reason for the diagnostic discrepancies was a different interpretation of morphological findings of the tumor, which accounted for 48.9% of the cases. This was followed by the unavailability of specialized immunohistochemical antibodies and the unavailability of genetic analysis. In summary, our study clarified the actual clinical impact of diagnostic discrepancy in bone and soft tissue tumors. This may underscore the value of pathology consultation, facilitating access to specialized diagnostic tools, and continued education. These measures are expected to improve diagnostic precision and ultimately benefit patients.

Discordance Between the Initial Diagnosis of Sarcomas and Subsequent Histopathological Revision and Molecular Analyses in a Sarcoma Reference Center in Brazil

PURPOSE

To investigate the discordance in sarcoma diagnoses between nonspecialized institutions following revision by dedicated sarcoma pathologists at a reference center in Brazil and the relevance of molecular pathology in this context.

METHODS

We conducted a retrospective analysis of sarcoma samples initially analyzed at outside laboratories and subsequently reviewed by two specialized pathologists between January 2014 and December 2020. After obtaining demographic and tumor characteristics, pathology results were matched and classified as complete discordance (CD; benign v malignant, sarcoma v other malignancies), partial concordance (similar diagnosis of connective tumor, but different grade/histological subtype/differentiation), and complete concordance (CC). The concordance for histology or grade, and the role of molecular assessments supporting the diagnosis were also independently determined. Statistical analyses were conducted through the kappa coefficient of agreement and adherence by χ2 test, χ2 test by Person, and Fisher exact test.

RESULTS

In total, 197 cases were included, with samples obtained predominately from male patients (57.9%) and localized/primary tumors (86.8%). Following revision, the most frequent final diagnoses were undifferentiated pleomorphic sarcoma (17.8%), well-differentiated/dedifferentiated liposarcoma (8.6%), and leiomyosarcoma (7.6%). CD was found in 13.2%, partial discordance in 45.2%, and CC in 41.6% of reviews (P < .001). We found a concordance for histology or grade of 53.5% (P < .001) and 51.8% (P < .001), respectively. Molecular assessments, comprising next-generation sequencing panels (79.5%) and fluorescent in situ hybridization (20.5%), were performed in 44 (22.3%) cases, with findings classified as of diagnostic relevance in 31.8%.

CONCLUSION

In nearly 60% of the cases, the initial sarcoma diagnosis was modified when revised by a reference center and dedicated pathologists, assisted by molecular pathology techniques. These results justify the assembly of referral networks in countries with limited health care resources.

The Impact of Expert Pathology Review and Molecular Diagnostics on the Management of Sarcoma Patients: A Prospective Study of the Hellenic Group of Sarcomas and Rare Cancers

Precise classification of sarcomas is crucial to optimal clinical management. In this prospective, multicenter, observational study within the Hellenic Group of Sarcoma and Rare Cancers (HGSRC), we assessed the effect of expert pathology review, coupled with the application of molecular diagnostics, on the diagnosis and management of sarcoma patients. Newly diagnosed sarcoma patients were addressed by their physicians to one of the two sarcoma pathologists of HGSRC for histopathological diagnostic assessment. RNA next-generation sequencing was performed on all samples using a platform targeting 86 sarcoma gene fusions. Additional molecular methods were performed in the opinion of the expert pathologist. Therefore, the expert pathologist provided a final diagnosis based on the histopathological findings and, when necessary, molecular tests. In total, 128 specimens from 122 patients were assessed. Among the 119 cases in which there was a preliminary diagnosis by a non-sarcoma pathologist, there were 37 modifications in diagnosis (31.1%) by the sarcoma pathologist, resulting in 17 (14.2%) modifications in management. Among the 110 cases in which molecular tests were performed, there were 29 modifications in diagnosis (26.4%) through the genomic results, resulting in 12 (10.9%) modifications in management. Our study confirms that expert pathology review is of utmost importance for optimal sarcoma diagnosis and management and should be assisted by molecular methods in selected cases.

Enhanced accuracy and reduced delay in diagnosing bone tumors within an expert sarcoma network: A nationwide study

INTRODUCTION

Primary bone tumors encompass a range of rare and diverse lesions. Pathological diagnosis poses significant challenges, with histological discrepancies extensively studied in soft tissue sarcomas but lacking specific investigation in bone lesions. This study aimed to determine the rate of major diagnostic discrepancies in primary bone tumors, assessing whether initial histological analysis within an expert referral center network reduces this rate and final diagnostic delay. Additionally, we examined the impact of mandatory systematic re-reading by expert pathologists on diagnostic variation and readjustment.

METHODS

Our study cohort comprised patients with primary bone tumors, drawn from the national prospective French sarcoma network database. A total of 1075 patients were included from 2018 to 2019.

RESULTS

The cohort exhibited a major discrepancy rate of 24%. Within the expert referral centers network, 49 cases (7%) showed major diagnostic discrepancies in the initial analysis, compared to 207 cases (57%) outside the network (p < 0.001). Regarding the final diagnostic delay, a mean of 2.8 weeks (±4.9) was observed within the network, contrasting with 6.5 weeks (±9.1) outside the network (p < 0.001). Systematic re-reading by an expert pathologist facilitated diagnosis readjustment in 75% of the 256 cases, with 68% of all diagnostic variations occurring preoperatively.

CONCLUSION

Early management within the expert network significantly reduced major diagnostic discrepancies and shortened the diagnosis delay by approximately a month. Expert pathologist systematic re-readings were responsible for diagnosis readjustments in three-quarters of cases, with two-thirds of all diagnostic variations occurring preoperatively, thereby mitigating the consequences of mistreatment.

Initial local resection versus early referral for spermatic cord sarcoma: Any impact on treatment timelines and oncological outcomes?

OBJECTIVES

Spermatic cord sarcomas are exceedingly rare, often misdiagnosed and subsequently improperly treated at local hospitals. This retrospective study looked at the oncological outcomes of spermatic cord sarcoma cases managed with curative intent resection at a tertiary referral sarcoma centre. We specifically studied how initial inadequate resections impact the oncologic outcomes compared to primary tumour resections at the reference centre.

METHODS

One hundred eighteen consecutive patients affected by primary, localized spermatic cord sarcoma surgically managed at our reference centre from January 2001 through January 2021 were included. Primary endpoints were local relapse free (LRFS), distant metastasis free (DMFS) and overall survival (OS). These outcomes were evaluated with multi-nomial logistic regression and Cox proportional hazards regression models for a co-relation to known patient, tumour and treatment-related prognostic factors, including a prior inadequate resection and time from diagnosis to a complete oncologic resection as independent variables. Secondarily, we compared the above variables and treatment intervals among the subgroups of primary versus re-resection surgery.

RESULTS

Over a median follow-up of 54 months (IQR 25-105), 12 patients (10.2%) developed local recurrence (LR) and 14 (11.6%) had distant metastasis (DM). 5-year local relapse (LRFS) and distant metastasis-free survival (DMFS) were 89.3% and 86.5%, respectively. Higher tumour grade and size were associated with a worse DMFS (p=<0.05). Likewise, marginal (R1) resection correlated with an inferior LRFS (p=< 0.05). Eighty-four patients (71.2%) had their initial diagnosis established on an inadequate surgical excision performed in a local hospital, followed by a re-excision at our centre (Re-resection group). During the same period, 34 (28.8%) were managed primarily with biopsy and treatment at our reference centre (Primary-resection group). The two groups had statistically significant differences in tumour size, histopathology, surgery duration, rate of postoperative complication and R0 resection (p < 0.005). Additionally, the difference in time intervals to achieve the treatment targets was statistically insignificant and did not correlate to the risk of recurrence as an independent variable. Residual disease was present in 51.2 % (n = 43) of the re-excision specimens. However, following a complete R0 resection, this did not correlate with a higher risk of recurrence (p = 0.481).

CONCLUSION

Prompt referral to a tertiary centre, where multidisciplinary evaluation and sound oncologic resections are the standard of treatment, can align the OS and DFS of patients receiving incomplete surgery elsewhere to those treated primarily in referral centres. The primary determinant of prognosis remains surgical margin, tumour size and grade.

Gynecological sarcomas, surgical management: primary, metastatic, and recurrent disease

Adult-type gynecological soft tissue and visceral sarcomas are rare tumors, with an estimated incidence of 13% of all sarcomas and 4% of all gynecological malignancies. They most often develop in the uterus (83%), followed by the ovaries (8%), vulva and vagina (5%), and other gynecological organs (2%). The objective of this review is to provide an overview of the current management of gynecological sarcomas, according to international guidelines. The management of gynecological sarcomas should follow the recommendations for the management of soft tissue and visceral sarcomas. Centralizing cases in expert centers improves patient survival, both for the diagnostic phase and for multidisciplinary therapeutic management. In the case of pelvic soft tissue sarcomas, a radiological biopsy is essential before any surgical decision is taken. In the case of a myometrial tumour which may correspond to a sarcoma, if conservative surgery such as myomectomy or morcellation is planned, an ultrasound-guided biopsy with pathological analysis including comparative genomic hybridization analysis must be carried out. In all cases, en bloc surgery, without rupture, is mandatory. Many rare histological subtypes require specific surgical management.

Clinico-Demographic Profile Of Soft Tissue Sarcoma- 5 Year Experience From A Tertiary Care Centre Of Eastern India

Soft tissue sarcomas (STS) are a diverse group of malignant mesenchymal neoplasm.But, due to their low prevalence, very little data is available worldwide as well as in India regarding their clinico-epidemiological pattern.In this study we analysed the clinico-demographic profile of STS patients attending a tertiary care centre of Eastern India over the last 5 years. We analyzed the prospectively maintained database of a tertiary care centre of West Bengal in Eastern India, and collected the data regarding the demography, clinical profile, pathology and treatment of STS patients who attended our OPD between 2017-2021. The objective was to assess the demographic and clinical data of STS patients of Eastern India and compare it with those of the reported literature from rest of the country as well as outside world. Most of the cases (27%) were between 41-50 years of age group with a slight male predominance (Male: Female = 1.01:1). Spindle cell sarcoma was the most common (24.3%) histology followed by undifferentiated pleomorphic sarcoma (15%) and extremities were the most common site of involvement (47.7%). 71% patients presented with stage III and advanced disease.81% patients underwent radical surgery,14% patient received neo-adjuvant and 60% received adjuvant radiotherapy.91% patients received systemic chemotherapy. To conclude, this study is one of its first from Eastern India and will act as a stepping stone for future studies concentrating on clinico-epidemiological profile, early diagnosis and treatment of STS.

Impact of guideline adherence and expert center referral on the early management and outcomes of uterine sarcoma patients: A retrospective analysis from the French NETSARC network

OBJECTIVE

Uterine sarcomas are rare tumors with a poor prognosis. Their diagnosis is often incidental, following surgery. Our goal was to examine the early management strategies for uterine sarcomas, and to assess the impact of guideline adherence and expert center referral on both the management approaches and the clinical outcomes in patients with uterine sarcomas.

METHODS

We retrospectively analyzed medical records from patients with uterine sarcoma referred to the Institut Curie and registered in the database of the French NETSARC network.

RESULTS

In total, 100 patients, with a median age of 54 years, were included in the analyses. On MRI scans (n = 36), all patients had at least two signs suggestive of malignancy, and 77.8 % had four or more signs. No preoperative biopsy was performed in 65.6 % of cases. Only 14.1 % of patients underwent initial surgery at an expert center. Surgery performed outside the network was significantly associated with morcellation (32.9 % vs. 0 %; p = 0.036), fewer negative margins (R0 margins 52.4 % vs. 100 %; p = 0.006), and poor adherence to surgical guidelines (28.3 vs. 72.7 %; p = 0.013). Multivariate analysis showed that non-adherence to surgical recommendations was not significantly associated with relapse-free survival (HR = 0.54; 95 % CI [0.21-1.38]), but was an independent predictor of poor overall survival (HR = 0.12; 95 % CI [0.03-0.52]; p = 0.005).

CONCLUSION

Despite a high frequency of suspicious clinical and radiological signs, a large proportion of women undergoing sarcoma surgery are treated outside of expert networks. We provide guidelines, integrating the clinical context and radiological signs to encourage early referral to reference centers for sarcoma.

Challenges and opportunities for sarcoma care and research in Latin America: a position paper from the LACOG sarcoma group

As a developing region, Latin America faces unique cancer control and prevention challenges, which are intensified when considering rare cancers, including sarcomas. Sarcomas are a group of malignancies that arise in the connective tissues of the body-such as muscle, fat, nerves, blood vessels, and bones-accounting for a diverse range of tumours that, although rare, require specialized attention. Sarcoma care and research in Latin America require a comprehensive approach that includes deeper epidemiologic knowledge, diagnostic capacity building, access to innovative treatments, increased patient advocacy, and strengthening of clinical research capacity. This article will review current challenges and opportunities for treating patients with sarcoma in Latin America and outline a pathway toward improvement for regional collaborative groups.

Challenges and opportunities in rare cancer research in China

Cancer is one of the major public health challenges in China. Rare cancers collectively account for a considerable proportion of all malignancies. The lack of awareness of rare cancers among healthcare professionals and the general public, the typically complex and delayed diagnosis, and limited access to clinical trials are key challenges. Recent years have witnessed an increase in funding for research related to rare cancers in China. In this review, we provide a comprehensive overview of rare cancers and summarize the status of research on rare cancers in China and overseas, including the trends of funding and publications. We also highlight the challenges and perspectives regarding rare cancers in China.

Evaluation of response to neoadjuvant chemotherapy in osteosarcoma using dynamic contrast-enhanced MRI: development and external validation of a model

OBJECTIVE

To identify which dynamic contrast-enhanced (DCE-)MRI features best predict histological response to neoadjuvant chemotherapy in patients with an osteosarcoma.

METHODS

Patients with osteosarcoma who underwent DCE-MRI before and after neoadjuvant chemotherapy prior to resection were retrospectively included at two different centers. Data from the center with the larger cohort (training cohort) was used to identify which method for region-of-interest selection (whole slab or focal area method) and which change in DCE-MRI features (time to enhancement, wash-in rate, maximum relative enhancement and area under the curve) gave the most accurate prediction of histological response. Models were created using logistic regression and cross-validated. The most accurate model was then externally validated using data from the other center (test cohort).

RESULTS

Fifty-five (27 poor response) and 30 (19 poor response) patients were included in training and test cohorts, respectively. Intraclass correlation coefficient of relative DCE-MRI features ranged 0.81-0.97 with the whole slab and 0.57-0.85 with the focal area segmentation method. Poor histological response was best predicted with the whole slab segmentation method using a single feature threshold, relative wash-in rate <2.3. Mean accuracy was 0.85 (95%CI: 0.75-0.95), and area under the receiver operating characteristic curve (AUC-index) was 0.93 (95%CI: 0.86-1.00). In external validation, accuracy and AUC-index were 0.80 and 0.80.

CONCLUSION

In this study, a relative wash-in rate of <2.3 determined with the whole slab segmentation method predicted histological response to neoadjuvant chemotherapy in osteosarcoma. Consistent performance was observed in an external test cohort.

[Diagnosis of uterine sarcomas and rare uterine mesenchymal tumours with malignant potential. Guidelines of the French Sarcoma Group and Rare Gynaecological Tumours]

The landscape of uterine sarcomas is becoming more complex with the description of new entities associated with recurrent driver molecular alterations. Uterine sarcomas, in analogy with soft tissue sarcomas, are distinguished into complex genomic and simple genomic sarcomas. Leiomyosarcomas and undifferentiated uterine sarcomas belong to complex genomic sarcomas group. Low-grade and high-grade endometrial stromal sarcomas, other rare tumors associated with fusion transcripts (such as NTRK, PDGFB, ALK, RET ROS1) and SMARCA4-deficient uterine sarcoma are considered simple genomic sarcomas. The most common uterine sarcoma are first leiomyosarcoma and secondly endometrial stromal sarcomas. Three different histological subtypes of leiomyosarcoma (fusiform, myxoid, epithelioid) are identified, myxoid and epithelioid leiomyosarcoma being more aggressive than fusiform leiomyosarcoma. The distinction between low-grade and high-grade endometrial stromal sarcoma is primarily morphological and immunohistochemical and the detection of fusion transcripts can help the diagnosis. Uterine PEComa is a rare tumor, which is distinguished into borderline and malignant, according to a risk assessment algorithm. Embryonal rhabdomyosarcoma of the uterine cervix is more common in children but can also occur in adult women. Embryonal rhabdomyosarcoma of the uterine cervix is almost always DICER1 mutated, unlike that of the vagina which is wild-type DICER1, and adenosarcoma which can be DICER1 mutated but with less frequency. Among the emerging entities, sarcomas associated with fusion transcripts involving the NTRK, ALK, PDGFB genes benefit from targeted therapy. The integration of molecular data with histology and clinical data allows better identification of uterine sarcomas in order to better treat them.

Complementary value of molecular analysis to expert review in refining classification of uncommon soft tissue tumors

The classification of many soft tissue tumors remains subjective due their rarity, significant overlap in microscopic features and often a non-specific immunohistochemical (IHC) profile. The application of molecular genetic tools, which leverage the underlying molecular pathogenesis of these neoplasms, have considerably improved the diagnostic abilities of pathologists and refined classification based on objective molecular markers. In this study, we describe the results of an international collaboration conducted over a 3-year period, assessing the added diagnostic value of applying molecular genetics to sarcoma expert pathologic review in a selected series of 84 uncommon, mostly unclassifiable mesenchymal tumors, 74 of which originated in soft tissues and 10 in bone. The case mix (71% historical, 29% contemporary) included mostly unusual and challenging soft tissue tumors, which remained unclassified even with the benefit of expert review and routine ancillary methods, including broad IHC panels and a limited number of commercially available fluorescence in situ hybridization (FISH) probes. All cases were further tested by FISH using a wide range of custom bacterial artificial chromosome probes covering most of known fusions in sarcomas, whereas targeted RNA sequencing was performed in 13 cases negative by FISH, for potential discovery of novel fusion genes. Tumor-defining molecular alterations were found in 48/84 tumors (57%). In 27 (32%) cases the tumor diagnosis was refined or revised by the additional molecular work-up, including five cases (6%), in which the updated diagnosis had clinical implications. Sarcoma classification is rapidly evolving due to an increased molecular characterization of these neoplasms, so unsurprisingly 17% of the tumors in this series harbored abnormalities only very recently described as defining novel molecularly defined soft tissue tumor subsets.

Comparison of radiological and pathological tumor sizes in resected non-small cell lung cancer

OBJECTIVES

In non-small cell lung cancer (NSCLC), T factor plays an important role in determining staging. The present study aimed to determine the validity of preoperative evaluation of clinical T (cT) factor by comparing radiological and pathological tumor sizes.

METHODS

Data for 1,799 patients with primary NSCLC who underwent curative surgery were investigated. The concordance between cT and pathological T (pT) factors was analyzed. Furthermore, we compared groups with an increase or decrease of ≥ 20% and groups with an increase or decrease of < 20% in the size change between preoperative radiological and pathological diameters.

RESULTS

The mean sizes of the radiological solid components and the pathological invasive tumors were 1.90 cm and 1.99 cm, respectively, correlation degree = 0.782. The group with increased pathological invasive tumor size (≥ 20%) compared with the radiologic solid component was significantly more likely female, consolidation tumor ratio (CTR) ≤ 0.5, and within cT1. Multivariate logistic analysis identified CTR < 1, cT ≤ T1, and adenocarcinoma as independent risk factors for increased pT factor.

CONCLUSION

The radiological invasive area of tumors with cT1, CTR < 1, or adenocarcinoma on preoperative CT may be underestimated compared with pathological invasive diameter.

Sarcoma care in the era of precision medicine

Sarcoma subtype classification is currently mainly based upon histopathological morphology. Molecular analyses have emerged as an efficient addition to the diagnostic workup and sarcoma care. Knowledge about the sarcoma genome increases, and genetic events that can either support a histopathological diagnosis or suggest a differential diagnosis are identified, as well as novel therapeutic targets. In this review, we present diagnostic, therapeutic, and prognostic molecular markers that are, or might soon be, used clinically. For sarcoma diagnostics, there are specific fusions highly supportive or pathognomonic for a diagnostic entity-for instance, SYT::SSX in synovial sarcoma. Complex karyotypes also give diagnostic information-for example, supporting dedifferentiation rather than low-grade central osteosarcoma or well-differentiated liposarcoma when detected in combination with MDM2/CDK4 amplification. Molecular treatment predictive sarcoma markers are available for gastrointestinal stromal tumor (GIST) and locally aggressive benign mesenchymal tumors. The molecular prognostic markers for sarcomas in clinical practice are few. For solitary fibrous tumor, the type of NAB2::STAT6 fusion is associated with the outcome, and the KIT/PDGFRA pathogenic variant in GISTs can give prognostic information. With the exploding availability of sequencing technologies, it becomes increasingly important to understand the strengths and limitations of those methods and their context in sarcoma diagnostics. It is reasonable to believe that most sarcoma treatment centers will increase the use of massive-parallel sequencing soon. We conclude that the context in which the genetic findings are interpreted is of importance, and the interpretation of genomic findings requires considering tumor histomorphology.

Diagnostic Superiority of Dual-Time Point [18F]FDG PET/CT to Differentiate Malignant from Benign Soft Tissue Tumors

[18F]FDG PET/CT is used in the workup of indeterminate soft tissue tumors (STTs) but lacks accuracy in the detection of malignant STTs. The aim of this study is to evaluate whether dual-time point [18F]FDG PET/CT imaging (DTPI) can be useful in this indication. In this prospective study, [18F]FDG PET/CT imaging was performed 1 h (t1) and 3 h (t2) after injection. Tumor uptake (SUVmax) was calculated at each time point to define a retention index (RI) corresponding to the variation between t1 and t2 (%). Sixty-eight patients were included, representing 20 benign and 48 malignant tumors (including 40 sarcomas). The RI was significantly higher in malignant STTs than in benign STTs (median: +21.8% vs. -2%, p < 0.001). An RI of >14.3% predicted STT malignancy with a specificity (Sp) of 90% and a sensitivity (Se) of 69%. An SUVmaxt1 of >4.5 was less accurate with an Sp of 80% and an Se of 60%. In a subgroup of tumors with at least mild [18F]FDG uptake (SUVmax ≥ 3; n = 46), the RI significantly outperformed the diagnostic accuracy of SUVmax (AUC: 0.88 vs. 0.68, p = 0.01). DTPI identifies malignant STT tumors with high specificity and outperforms the diagnostic accuracy of standard PET/CT.

Enhancing Healthcare for Sarcoma Patients: Lessons from a Diagnostic Pathway Efficiency Analysis

Sarcomas, rare and with lower survival rates than common tumors, offer insights into healthcare efficiency via the analysis of the total interval of the diagnostic pathway, combining the patient interval (time between the first symptom and visit with a physician) and diagnostic interval (time between first physician visit and histological diagnosis). Switzerland's healthcare system, Europe's costliest, lacks research on treating rare conditions, like mesenchymal tumors. This study examines the total interval of the diagnostic pathway for optimization strategies. Analyzing a dataset of 1028 patients presented from 2018 to 2021 to the Swiss Sarcoma Board (MDT/SB-SSN), this retrospective analysis delves into bone sarcoma (BS), soft-tissue sarcoma (STS), and their benign counterparts. Demographic and treatment data were extracted from medical records. The patient interval accounted for the largest proportion of the total interval and secondary care interval for the largest proportion of the diagnostic interval. Age, grade, and localization could be elicited as influencing factors of the length of different components of the total interval. An increasing age and tumor size, as well as the axial localization, could be elicited as factors increasing the probability of sarcoma. The patient and secondary care interval (SCI) offer the greatest potential for optimization, with SCI being the bottleneck of the diagnostic interval. New organizational structures for care work-ups are needed, such as integrated practice units (IPU) as integral part of value-based healthcare (VBHC).

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.

A primary multiple pleomorphic rhabdomyosarcoma of the heart in an adult dog

BACKGROUND

Heart tumors are rare in dogs. They can be benign or malignant. Clinical signs depend primarily on the location of the tumor and its effect on blood flow.

CASE PRESENTATION

An eleven-year-old crossbreed male dog lethargic and anorectic for previous 3 days was presented to the veterinary clinic. The focused ultrasound assessment with sonograms in trauma (FAST) revealed multiple tumors in the heart which were then confirmed in echocardiographic examination performed by a veterinary cardiologist. Due to the poor general condition and grave prognosis, the dog was humanely euthanized. The autopsy revealed numerous intracardiac tumors in all four heart chambers. No proliferative changes were found in other organs either in thoracic or abdominal cavity. Immunohistochemical examination was performed using formalin-fixed, paraffin-embedded tissue from heart masses. The antibodies against myoglobin, desmin, smooth muscle actin, vimentin, CD34, S100, and pan-cytokeratin (AE1/AE3) were used. Microscopically, the tumor was composed of fascicles of spindle-shaped cells with pale eosinophilic cytoplasm with round, oval, and focally elongated nuclei and one or two prominent nucleoli. The tumor cells showed strong diffuse cytoplasmic immunopositivity for myoglobin and vimentin and focal staining for desmin. Immunostainings for smooth muscle actin-SMA, CD34, pan-cytokeratin, S-100 protein were negative. The immunohistochemical staining pattern confirmed rhabdomyosarcoma.

CONCLUSIONS

This is the first description of the primary multiple heart rhabdomyosarcoma in a dog.

Indicators of clinical performance in monitoring soft tissue sarcoma management: a population-based perspective

Background

Soft tissue sarcomas (STS) are rare malignancies which prognosis varies significantly by primary site, histological subtype, and tumor stage. Their low incidence, and the complexity of their clinico-pathological characteristics demand standardized, cancer-tailored diagnostics and therapies managed at high-volume, multidisciplinary care centers. This study evaluates the quality of STS management in north-east Italy (Veneto Region) through a list of ad hoc defined clinical indicators.

Methods

This population-based study concerns all incident cases of STS in 2018 (214 cases) recorded in the adult population censored by the Veneto's regional Cancer Registry. Based on the international literature, a multidisciplinary working group of experts identified a set of indicators for monitoring the quality of diagnostic, therapeutic, and end-of-life clinical interventions. The quality of care was assessed by comparing the reference thresholds with the indicators' values achieved in clinical practice.

Results

Diagnostic procedures showed poor adherence to the thresholds, with a low percentage of histological diagnoses validated by a second opinion. The indicators relating to the surgical treatment of superficial, small, low-grade STS, or of medium, high-grade STS of the head-neck, trunk, or limbs were consistent with the thresholds, while for intermediate, high-grade (large-sized, deep) and retroperitoneal STS they fell significantly below the thresholds.

Conclusion

A critical evaluation of the clinical indicators allowed to uncover the procedures needing corrective action. Monitoring clinical care indicators improves cancer care, confirms the importance of managing rare cancers at highly specialized, high-volume centers, and promotes the ethical sustainability of the healthcare system.

Survival Outcomes of Ewing Sarcoma and Rhabdomyosarcoma by High- versus Low-Volume Cancer Centres in British Columbia, Canada

Due to the rarity and complexity of treatment for Ewing sarcoma and rhabdomyosarcoma, studies demonstrate improved patient outcomes when managed by a multidisciplinary team at high-volume centres (HVCs). Our study explores the difference in outcomes of Ewing sarcoma and rhabdomyosarcoma patients based on the centre of initial consultation in British Columbia, Canada. This retrospective study assessed adults diagnosed with Ewing sarcoma and rhabdomyosarcoma between 1 January 2000 and 31 December 2020 undergoing curative intent therapy in one of five cancer centres across the province. Seventy-seven patients were included, 46 seen at HVCs and 31 at low-volume centres (LVCs). Patients at HVCs were younger (32.1 vs. 40.8 years, p = 0.020) and more likely to receive curative intent radiation (88% vs. 67%, p = 0.047). The time from diagnosis to first chemotherapy was 24 days shorter at HVCs (26 vs. 50 days, p = 0.120). There was no significant difference in overall survival by treatment centre (HR 0.850, 95% CI 0.448-1.614). Variations in care exist amongst patients treated at HVCs vs. LVCs, which may reflect differences in access to resources, clinical specialists, and varying practice patterns across centres. This study can be used to inform decisions regarding triaging and centralization of Ewing sarcoma and rhabdomyosarcoma patient treatment.

Extrapelvic Endometriosis Mimicking Peritoneal Surface Malignancy: Case Report and a Review of Literature

Extrapelvic endometriosis is a rare presentation of endometriosis with atypical clinical symptoms. It can mimic peritoneal surface malignancy, as well as some abdominal infectious diseases. A 29-year-old Moroccan woman presented with abdominal pain, progressive abdominal distention, and an intermittent inflammatory syndrome. Imaging revealed multiple, progressively growing abdominal cysts. She had elevated tumor markers CA125 and CA19.9. Despite thorough investigation, several differential diagnoses persisted for a long time. Definitive pathological diagnosis could only be established after debulking surgery. Literature review on malignant and benign conditions causing multicystic abdominal distention is provided. When definitive diagnosis is not established, but suspicion for peritoneal malignancy remains, a debulking procedure can be undertaken. Organ preservation can be pursued whenever benign disease is still considered. In case of malignancy, short-term (curative) debulking procedure with or without hyperthermic intraperitoneal chemotherapy (HIPEC) can be proposed.

Epidemiology of rare cancers in India and South Asian countries - remembering the forgotten

Background

Rare cancers (RCs) are challenging to manage and are "forgotten cancers" though they collectively constitute a significant proportion of all cancers (∼20%). As a first step towards streamlining care, there is an unmet need to map the epidemiology of RCs in South Asian Association for Regional Collaboration (SAARC) countries.

Methods

The authors collected data from 30 Population-Based Cancer Registries (PBCR) of India and the published national registries of Nepal, Bhutan and Sri Lanka (SL) and compared them with the standard RARECAREnet RC list.

Findings

With the standard definition of crude incidence rates (CR) ≤6/100,0000 per population, 67.5%, 68.3%, 62.3% and 37% of all incident cancers qualify as RCs in India, Bhutan, Nepal and SL, respectively. An arbitrary cut-off CR ≤3 appears more appropriate with 43%, 39.5%, 51.8% and 17.2% of cancers identified as RCs, respectively, due to the lower cancer incidence.There are similarities and notable differences between the RC lists of the SAARC region with that of the European RC list. Oral cavity cancers are rare in Europe, while pancreas, rectum, urinary bladder and melanomas are common. In addition, uterine, colon and prostatic cancers are rare in India, Nepal and Bhutan. In SL, thyroid cancer is common. There are gender-related and regional differences in RC trends in the SAARC countries.

Interpretation

There is an unmet need in SAARC nations to capture epidemiological nuances in rare cancers. Understanding the unique issues in the developing world may guide policymakers to adopt appropriate measures to improve RC care and tailor public health interventions.

Funding

None.

[Multimodal treatment of localized high-grade soft tissue sarcomas of the extremities : Summary and discussion of the current S3 guidelines on adult soft tissue sarcomas and the ESMO guidelines on soft tissue and visceral sarcomas]

Soft tissue sarcomas are rare, heterogeneous tumors that are frequently in the extremities. Treatment includes surgical resection, combination chemotherapy and/or radiotherapy, as well as supplementary procedures such as isolated limb perfusion and regional deep hyperthermia. The prognosis depends on the tumor stage and the approximately 70 histological subtypes, with specific treatment approaches existing only for some subtypes. This review summarizes the recommendations of the German S3 guideline "Adult Soft Tissue Sarcomas" and the European Society for Medical Oncology (ESMO) guideline "Soft tissue and visceral sarcomas" regarding the diagnostic workup and therapy of soft tissue sarcomas of the extremities.

Datasets for reporting of soft-tissue sarcoma: recommendations from the International Collaboration on Cancer Reporting (ICCR)

AIMS

Soft-tissue tumours are rare and both accurate diagnosis and proper treatment represent a global challenge. Current treatment guidelines also recommend review by specialised pathologists. Here we report on international consensus-based datasets for the pathology reporting of biopsy and resection specimens of soft-tissue sarcomas. The datasets were produced under the auspices of the International Collaboration on Cancer Reporting (ICCR), a global alliance of international pathology and cancer organisations.

METHODS AND RESULTS

According to the ICCR's guidelines for dataset development, an international expert panel consisting of pathologists, a surgical oncologist, and a medical oncologist produced a set of core and noncore data items for biopsy and resection specimens based on a critical review and discussion of current evidence. All professionals involved were subspecialised soft-tissue sarcoma experts and affiliated with tertiary referral centres. Commentary was provided for each data item to explain the rationale for selecting it as a core or noncore element, its clinical relevance, and to highlight potential areas of disagreement or lack of evidence, in which case a consensus position was formulated. Following international public consultation, the documents were finalised and ratified, and the datasets, which included a synoptic reporting guide, were published on the ICCR website.

CONCLUSION

These first international datasets for soft-tissue sarcomas are aimed to promote high-quality, standardised pathology reporting. Their adoption will improve consistency of reporting, facilitate multidisciplinary communication, and enhance comparability of data, all of which will help to improve patient's management.

Establishing an RNA fusions panel in soft tissue sarcoma with clinical validation

The diagnosis and classification of soft tissue sarcomas (STS) remain challenging because of the rarity and overlapping morphologic manifestations of diverse STS subtypes. Characteristic gene fusions are commonly detected in STS and represent useful diagnostic markers. This study established and validated a custom-designed RNA sequencing panel that identified 64 gene fusions in STS. The analytical performance validation yielded excellent accuracy, with 100% (95% CI, 94.40%-100%) sensitivity and 93.33% (95% CI, 68.05%-99.83%) specificity. Clinical performances were further confirmed with 145 clinical formalin-fixed and paraffin-embedded (FFPE) samples from STS patients. Fusions were detected in 40% of samples (58/145). The common fusions SS18-SSX family, EWSR1-related fusions, COL1A1-PDGFB, FOXO1-associated fusions, and FUS-associated fusions were identified in corresponding STS subtypes. The RNA panel detected specific fusions in several cases where no conclusive diagnosis can be made based on the morphology and immunohistochemistry results. Data collected in this study demonstrate that the RNA fusions panel can better classify STS subtypes and serve as a good supplement for histopathology, exhibiting a great potential for the STS precise diagnosis.

Diagnostic errors in musculoskeletal oncology and possible mitigation strategies

The objective of this paper is to explore sources of diagnostic error in musculoskeletal oncology and potential strategies for mitigating them using case examples. As musculoskeletal tumors are often obvious, the diagnostic errors in musculoskeletal oncology are frequently cognitive. In our experience, the most encountered cognitive biases in musculoskeletal oncologic imaging are as follows: (1) anchoring bias, (2) premature closure, (3) hindsight bias, (4) availability bias, and (5) alliterative bias. Anchoring bias results from failing to adjust an early impression despite receiving additional contrary information. Premature closure is the cognitive equivalent of "satisfaction of search." Hindsight bias occurs when we retrospectively overestimate the likelihood of correctly interpreting the examination prospectively. In availability bias, the radiologist judges the probability of a diagnosis based on which diagnosis is most easily recalled. Finally, alliterative bias occurs when a prior radiologist's impression overly influences the diagnostic thinking of another radiologist on a subsequent exam. In addition to cognitive biases, it is also important for radiologists to acknowledge their feelings when making a diagnosis to recognize positive and negative impact of affect on decision making. While errors decrease with radiologist experience, the lack of application of medical knowledge is often the primary source of error rather than a deficiency of knowledge, emphasizing the need to foster clinical reasoning skills and assist cognition. Possible solutions for reducing error exist at both the individual and the system level and include (1) improvement in knowledge and experience, (2) improvement in clinical reasoning and decision-making skills, and (3) improvement in assisting cognition.

The impact of additional pathology analysis on the diagnosis and management of soft tissue tumours: a 10-year,retrospective study

In order to characterise soft tissue tumours, pathologists often utilise specialised additional tests, or may seek opinions from subspecialist pathologists due to rarity or complex morphology. Additionally, further review may be sought by subspecialist sarcoma pathologists, such as those at our tertiary referral centre in Sydney, Australia. The aim of this study was to examine the impact on diagnosis and management of this external review, following diagnosis at a specialised sarcoma unit. We collated the results of all additional external ancillary tests and specialist reviews over a 10-year period and characterised the impact on the preliminary diagnosis as 'confirmed', 'new' or 'no clear diagnosis'. We subsequently noted whether the additional findings resulted in a clinically significant change in management. Of the 136 cases sent away, 103 patients had their initial diagnosis confirmed, 29 patients received a new diagnosis and, for four patients, the diagnosis remained uncertain. Nine of the 29 patients receiving a new diagnosis had their management altered. This study demonstrated that within our specialised sarcoma unit, the majority of diagnoses provided by our specialist pathologists are confirmed on additional external testing and review, but external review does provide additional assurance and benefit to the patient.

Management of Recurrent Retroperitoneal Sarcoma

Recurrence after resection of retroperitoneal sarcoma is common and varies by histological subtype. Pattern of recurrence is similarly affected by histology (e.g., well-differentiated liposarcoma is more likely to recur locoregionally, whereas leiomyosarcoma is more likely to develop distant metastases). Radiotherapy may provide effective locoregional control in limited circumstances and the data on the impact of chemotherapy are scant. Surgery for locally recurrent disease is associated with the greatest survival benefit; however, data are retrospective and from a highly selected subgroup of patients. Limited retrospective data have also suggested a survival association with the resection of limited distant metastases. Given the complexity of these patients, multidisciplinary evaluation at a high-volume sarcoma center is critical.

Treatment Pathways and Prognosis in Advanced Sarcoma with Peritoneal Sarcomatosis

Sarcomas represent a heterogeneous group of mesenchymal malignancies that most commonly occur in the extremities, retroperitoneum, and head and neck. Intra-abdominal manifestations are rare and prove particularly difficult to treat when peritoneal sarcomatosis is present. Because of the overall poor prognosis of the disease, a tailored approach to surgical management is essential to achieve satisfactory outcomes with limited morbidity. We present the perioperative and long-term outcomes of 19 cases of sarcoma with peritoneal sarcomatosis treated surgically at our hospital. Treatment pathways were reviewed and clinical follow-up was performed. Patient characteristics, medical history, tumor subtype, surgical approach, hospital stay, complications, follow-up, and overall survival (OS) were assessed. Our patients were 9 women and 10 men with a median age of 45.9 years (18-88) and a median survival of 30 months (0-200). In most cases, peritoneal sarcomatosis was either discovered during surgery or the procedure was performed with palliative intent from the beginning. The surgical approach in these cases is very heterogeneous and should consider a variety of factors to tailor an approach for each patient. Sharing our experiences will help to increase knowledge about this rare disease and provide insight into the management of future cases.

Trabectedin use in soft-tissue sarcoma patients in a real-world setting: Data from an Italian national drug-access registry

Trabectedin is a marine-derived anticancer drug approved for the treatment of patients with advanced soft-tissue sarcomas (STS). Here, we aimed to analyze its use in a large cohort of STS patients treated in Italy in a real-world setting. Data on STS patients treated with trabectedin in Italy were prospectively collected from January 2013 to December 2019 by the national drug regulator, the Italian Medicines Agency (AIFA). Time-to-off-treatment (TToT) was defined as the time between the initial prescription of trabectedin and the date of treatment discontinuation for any cause. The impact of the different baseline covariates, including the initial prescribed dose of trabectedin, on TToT was evaluated using an accelerated failure time (AFT) models with log-logistic distribution. In total, we analyzed data from 2633 sarcoma patients and 14 950 individual cycles of trabectedin. The median number of cycles of trabectedin received per patient was 3 (interquartile range 2-7). The labeled 1.5 mg/sqm dose was used in 27.3% of all first prescriptions. Overall, the median TToT was 93 days. In the final AFT model, the variables significantly associated to longer TToT were female gender (+13% increase in TToT); ECOG performance status 0 (+50%); histological diagnosis of leiomyosarcoma (+22%), well-differentiated/dedifferentiated liposarcoma (+72%) or myxoid liposarcoma (+61%); receiving treatment in a high-volume center (+23%). In this large real-world cohort of STS patients treated with trabectedin, our findings support the use of trabectedin in STS patients, in particular in leiomyosarcoma and liposarcoma patients, and highlight the role of treatment center volume in their management.

Outcomes for Children With Type II and Type III Pleuropulmonary Blastoma Following Chemotherapy: A Report From the International PPB/DICER1 Registry

PURPOSE

Pleuropulmonary blastoma (PPB) is the most common primary lung neoplasm of infancy and early childhood. Type II and type III PPB have historically been associated with a poor prognosis.

METHODS

Patients with known or suspected PPB were enrolled in the International PPB/DICER1 Registry. Medical records were abstracted with follow-up ascertained annually. All PPB diagnoses were confirmed by central pathology review. Beginning in 2007, the IVADo regimen (ifosfamide, vincristine, actinomycin-D, and doxorubicin) was recommended as a potential treatment regimen for children with type II and type III PPB. This regimen was compared with a historical control cohort.

RESULTS

From 1987 to 2021, 314 children with centrally confirmed type II and type III PPB who received upfront chemotherapy were enrolled; 132 children (75 with type II and 57 with type III) received IVADo chemotherapy. Adjusted analyses suggest improved overall survival for children treated with IVADo in comparison with historical controls with an estimated hazard ratio of 0.65 (95% CI, 0.39 to 1.08). Compared with localized disease, distant metastasis at diagnosis was associated with worse PPB event-free survival and overall survival with hazard ratio of 4.23 (95% CI, 2.42 to 7.38) and 4.69 (95% CI, 2.50 to 8.80), respectively.

CONCLUSION

The use of IVADo in children with type II and type III PPB resulted in similar-to-improved outcomes compared with historical controls. Inferior outcomes with metastatic disease suggest the need for novel therapies. This large cohort of uniformly treated children with advanced PPB serves as a benchmark for future multicenter therapeutic studies for this rare pediatric tumor.