A systematic review of combined surgery and brachytherapy approaches for children and young people with relapsed and refractory rhabdomyosarcoma (Local-REFoRMS)

Approximately one third of children with rhabdomyosarcoma relapse or have refractory disease. Treatment approaches include a combination of systemic therapies and local therapies, directed at tumour site(s). This review was conducted to evaluate the effectiveness and safety of the combination of surgery and brachytherapy as local therapy for treating children and young people with relapsed/refractory rhabdomyosarcoma. This review identified studies based on a previous systematic review looking at the treatments for children and young people under 18 years old with relapsed/refractory rhabdomyosarcoma. Studies conducted after 2000 were included. Survival outcomes, relapse rates, adverse events and functional outcomes were extracted. From 16,965 records identified in the baseline systematic review, 205 included the words 'AMORE' or 'brachytherapy', and were screened for eligibility in this substudy. Thirteen studies met the inclusion criteria for Local-REFoRMS, including over 55 relapsed and refractory rhabdomyosarcoma patients. Most studies were retrospective cohort studies conducted within Europe. Most patients had embryonal disease within the head and neck or bladder/prostate regions, and received local therapy for first relapse. Approximately one quarter of patients relapsed following surgery and brachytherapy, with local relapses occurring more than metastatic relapse. Adverse events and functional outcomes were infrequently reported, but related to the site of surgery and brachytherapy. Study quality was limited by inconsistent reporting and potential selection bias. Outcomes following surgery and brachytherapy for a selected group of relapsed and refractory rhabdomyosarcoma show reasonable benefits, but reporting was often unclear and based on small sample sizes.

Differential metabolic secretion between mdx mouse-derived spindle cell sarcomas and rhabdomyosarcomas drives tumor type development

The dystrophin (DMD) gene is recognized for its significance in Duchenne muscular dystrophy (DMD), a lethal and progressive skeletal muscle disease. Some DMD patients, as well as model mice with muscular dystrophy (mdx), spontaneously develop various types of tumors, among which rhabdomyosarcoma (RMS) is the most prominent. By contrast, spindle cell sarcoma (SCS) has rarely been reported in patients or mdx mice. In this study, we aimed to use metabolomics to better understand the rarity of SCS development in mdx mice. Gas chromatography-mass spectrometry was employed to compare the metabolic profiles of spontaneously developed SCS and RMS tumors from mdx mice, and metabolite supplementation assays and silencing experiments were used to assess the effects of metabolic differences in SCS tumor-derived cells. The levels of 75 metabolites exhibited differences between RMS and SCS, 25 of which were significantly altered. Further characterization revealed downregulation of non-essential amino acids, including alanine, in SCS tumors. Alanine supplementation enhanced the growth, epithelial-mesenchymal transition, and invasion of SCS cells. Reduction of intracellular alanine via knockdown of the alanine transporter Slc1a5 reduced the growth of SCS cells. Lower metabolite secretion and reduced proliferation of SCS tumors may explain the lower detection rate of SCS in mdx mice. Targeting of alanine depletion pathways may have potential as a novel treatment strategy.

Event-free survival in relapsed and refractory rhabdomyosarcoma treated on cooperative group phase II trials: A report from the Children's Oncology Group

BACKGROUND

Novel therapies are needed for relapsed and refractory rhabdomyosarcoma (RRMS). Phase II clinical trials in RRMS have typically utilized radiologic response as the primary activity endpoint, an approach that poses several limitations in RRMS. In this analysis, we aimed to estimate an event-free survival (EFS) endpoint for RRMS that could be used as a benchmark for future studies.

PROCEDURE

We performed a retrospective study of patients with RRMS enrolling on 13 single-agent phase II Children's Oncology Group and legacy group trials from 1997 to 2016. All included trials used radiographic response as their primary activity endpoint. Six-month EFS was estimated from time of trial enrollment with 95% confidence intervals. Clinical characteristics, including trial of enrollment, sex, age, race, histology, number of prior chemotherapies, and radiographic response were evaluated for their impact on 6-month EFS.

RESULTS

We identified 175 patients across 13 trials. The 6-month EFS was 16.8% (11.6%-22.8%). No differences were seen in 6-month EFS based on age, sex, race, or histology. There were nonsignificant trends toward improved 6-month EFS for patients with less than or equal to two prior lines of therapy versus higher than two, for patients enrolled on trials that achieved their primary radiographic response endpoint versus trials that did not, and for patients who achieved complete or partial response compared to those achieving stable disease.

CONCLUSIONS

The prognosis of RRMS enrolled on single-agent phase II trials is poor. This pooled 6-month EFS of RRMS on single-agent trials may be used as a RRMS-specific benchmark for future single-agent phase II trials.

A rare case of metastatic paraspinal rhabdomyosarcoma presenting with proptosis in an adult patient

Secondary metastasis of rhabdomyosarcoma (RMS) to the orbit from a distant primary site is extremely rare in adults. In this article, we describe the case of a 24-year-old male presenting with proptosis, diplopia, and headaches concurrently with a histologically confirmed diagnosis of PAX3-FOXO1 positive paraspinal alveolar rhabdomyosarcoma. An orbital MRI revealed a fusiform mass arising from the inferior rectrus, displaying necrotic and irregular morphology consistent with malignancy. The patient is currently undergoing intensive chemotherapy. The objective of this case report is to highlight the rarity of an extraocular metastasis of RMS in an adult patient, alongside the importance of considering metastatic disease in a patient with fulminant unilateral proptosis.

Adolescents and young adults with rhabdomyosarcoma: A report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group

INTRODUCTION

The impact of established prognostic factors on survival outcomes for childhood rhabdomyosarcoma (RMS) have not been well described in the adolescent and young adult (AYA) RMS patient population.

METHODS

This is a retrospective analysis of patients with newly diagnosed RMS enrolled between 1997 and 2016 on seven previously reported Children's Oncology Group (COG) clinical trials. Demographics, clinical features, treatment details, and outcome data were collected. Five-year event-free survival (EFS) and overall survival (OS) were estimated for patients diagnosed at age 15-39 years and those diagnosed under age 15 years using the Kaplan-Meier method. Log-rank test was used to compare prognostic factors for EFS and OS. Factors significant in the univariable analysis were included in a Cox proportional hazards regression model. Nonsignificant covariates were removed from the multiple regression model.

RESULTS

Total 2151 patients including 402 AYAs were analyzed. AYAs were more likely to present with primary tumors ≥5 cm in size, metastatic disease, alveolar histology, and have FOXO1 fusions compared to children. Five-year EFS for the AYA cohort was 44.2% versus 67% for children (p < .001), and 5-year OS was 52% for the AYA cohort versus 78% for children (p < .001). Multivariable analysis revealed tumor site, size and invasiveness, clinical group, and histology were prognostic in AYAs.

CONCLUSION

AYAs with RMS have a poorer prognosis compared to younger children due to multiple factors. Further research focused on AYAs to better understand RMS biology and improve treatments is critical to improve survival.

Embryonal Rhabdomyosarcoma of the Prostate: Clinico-Pathological Highlights with Review of Literature

Rhabdomyosarcoma (RMS) is the third most common extra-cranial sarcoma occurring in childhood, adolescents, and young adults (AYAs); and is rare in adults. Literature about RMS mainly considers RMS in AYAs, either with that in the children or adults, even though histological, molecular, and clinical characteristics of RMS in AYAs are significantly different from either of the two. Herein, we report a case of prostatic embryonal RMS, in a 17-year-old boy, along with the review of literature of prostatic RMS, with emphasis on AYAs. Our patient presented with clinical complaints of acute urinary retention, Grade IV prostatomegaly and, low serum prostate-specific-antigen (0.11ng/dl). The diagnosis was clinched by prostatic biopsy, which revealed diffuse 'small round blue cell' tumour admixed with larger rhabdomyoblasts, displaying positivity for desmin and myogenin, on immunohistochemistry. Clinicians should be mindful that RMS is found in all age groups ranging from childhood to adults; however, the clinical, histological, and molecular features are different. RMS in AYAs is often treated according to the guidelines provided for the paediatric age group. Treatment mostly comprises a multimodality approach, including surgery with/without chemo- and radiotherapy. Prognosis in AYAs is worse than in children but is better than in adults. Thus, early diagnosis gains utmost importance to provide comparatively more probability of rendering treatment and, hopefully, a better quality of life.

A systematic review of early phase studies for children and young people with relapsed and refractory rhabdomyosarcoma: The REFoRMS-SR project

Rhabdomyosarcoma is the commonest soft tissue sarcoma in children. Around one-third of children with rhabdomyosarcoma experience relapse or have refractory disease, which is associated with a poor prognosis. This systematic review of early phase studies in pediatric relapsed/refractory rhabdomyosarcoma was conducted to inform future research and provide accurate information to families and clinicians making difficult treatment choices. Nine databases and five trial registries were searched in June 2021. Early phase studies of interventions for disease control in patients under 18 years old with relapsed/refractory rhabdomyosarcoma were eligible. No language/geographic restrictions were applied. Studies conducted after 2000 were included. Survival outcomes, response rates, quality of life and adverse event data were extracted. Screening, data extraction and quality assessment (Downs and Black Checklist) were conducted by two researchers. Owing to heterogeneity in the included studies, narrative synthesis was conducted. Of 16,965 records screened, 129 published studies including over 1100 relapsed/refractory rhabdomyosarcoma patients were eligible. Most studies evaluated systemic therapies. Where reported, 70% of studies reported a median progression-free survival ≤6 months. Objective response rate was 21.6%. Adverse events were mostly hematological. One-hundred and seven trial registry records of 99 studies were also eligible, 63 of which report they are currently recruiting. Study quality was limited by poor and inconsistent reporting. Outcomes for children with relapsed/refractory rhabdomyosarcoma who enroll on early phase studies are poor. Improving reporting quality and consistency would facilitate the synthesis of early phase studies in relapsed/refractory rhabdomyosarcoma (PROSPERO registration: CRD42021266254).

A study of five cases and review of the literature

AIMS

Spindle-cell/sclerosing rhabdomyosarcomas (SS-RMS) are clinically and genetically heterogeneous. They include three well-defined molecular subtypes, of which those with EWSR1/FUS::TFCP2 rearrangements were described only recently. This study aimed to evaluate five new cases of SS-RMS and to perform a clinicopathological and statistical analysis of all TFCP2-rearranged SS-RMS described in the English literature to more comprehensively characterize this rare tumour type.

METHODS AND RESULTS

Cases were retrospectively selected and studied by immunohistochemistry, fluorescence in situ hybridization with EWSR1/FUS and TFCP2 break-apart probes, next-generation sequencing (Archer FusionPlex Sarcoma kit and TruSight RNA Pan-Cancer Panel). The PubMed database was searched for relevant peer-reviewed English reports. Five cases of SS-RMS were found. Three cases were TFCP2 rearranged SS-RMS, having FUSex6::TFCP2ex2 gene fusion in two cases and triple gene fusion EWSR1ex5::TFCP2ex2, VAX2ex2::ALKex2 and VAX2intron2::ALKex2 in one case. Two cases showed rhabdomyoblastic differentiation and spindle-round cell/sclerosing morphology, but were characterized by novel genetic fusions including EWSR1ex8::ZBTB41ex7 and PLOD2ex8::RBM6ex7, respectively. In the statistical analysis of all published cases, CDKN2A or ALK alterations, the use of standard chemotherapy and age at presentation in the range of 18-24 years were negatively correlated to overall survival.

CONCLUSION

EWSR1/FUS::TFCP2-rearranged SS-RMS is a rare rhabdomyosarcoma subtype, affecting predominantly young adults with average age at presentation 34 years (median 29.5 years; age range 7-86 years), with a predilection for craniofacial bones, rapid clinical course with frequent bone and lung metastases, and poor prognosis (3-year overall survival rate 28%).

FGFR1 fusions as a novel molecular driver in rhabdomyosarcoma

The wide application of RNA sequencing in clinical practice has allowed the discovery of novel fusion genes, which have contributed to a refined molecular classification of rhabdomyosarcoma (RMS). Most fusions in RMS result in aberrant transcription factors, such as PAX3/7::FOXO1 in alveolar RMS (ARMS) and fusions involving VGLL2 or NCOA2 in infantile spindle cell RMS. However, recurrent fusions driving oncogenic kinase activation have not been reported in RMS. Triggered by an index case of an unclassified RMS (overlapping features between ARMS and sclerosing RMS) with a novel FGFR1::ANK1 fusion, we reviewed our molecular files for cases harboring FGFR1-related fusions. One additional case with an FGFR1::TACC1 fusion was identified in a tumor resembling embryonal RMS (ERMS) with anaplasia, but with no pathogenic variants in TP53 or DICER1 on germline testing. Both cases occurred in males, aged 7 and 24, and in the pelvis. The 2nd case also harbored additional alterations, including somatic TP53 and TET2 mutations. Two additional RMS cases (one unclassified, one ERMS) with FGFR1 overexpression but lacking FGFR1 fusions were identified by RNA sequencing. These two cases and the FGFR1::TACC1-positive case clustered together with the ERMS group by RNAseq. This is the first report of RMS harboring recurrent FGFR1 fusions. However, it remains unclear if FGFR1 fusions define a novel subset of RMS or alternatively, whether this alteration can sporadically drive the pathogenesis of known RMS subtypes, such as ERMS. Additional larger series with integrated genomic and epigenetic datasets are needed for better subclassification, as the resulting oncogenic kinase activation underscores the potential for targeted therapy.

Experience With Medical Marijuana in a Pediatric Palliative Care Clinic: Case Report

Children receiving palliative care have life-limiting or life-threatening conditions, which include symptoms ranging from unpleasant to intolerable suffering. We describe three diverse cases of medical marijuana within ambulatory pediatric palliative care, highlighting use for spasticity, refractory seizures, and cancer-related symptoms. Included are caregiver perspectives of their child's experience with medical marijuana. This population has high potential for positive effects from medical marijuana therapy, particularly for maximizing quality of life.

Nomogram to predict prognosis of head and neck rhabdomyosarcoma patients in children and adolescents

Purpose

This study aims to explore the prognostic factors of head and neck rhabdomyosarcoma (HNRMS) in children and adolescents and construct a simple but reliable nomogram model for estimating overall survival (OS) of patients.

Methods

Data of all HNRMS patients during 2004-2018 were identified from the Surveillance, Epidemiology, and End Result database. Kaplan-Meier method was performed to calculate OS stratified by subgroups and comparison between subgroups was completed by log-rank test. Univariate and multivariate Cox regressions analysis were employed for identifying independent predictors, which subsequently were used for a predictive model by R software, and the efficacy of the model was evaluated by applying receiver operating curve (ROC), calibration and decision curve analysis (DCA).

Results

A total of 446 patients were included in the study. The 1-, 3-, and 5-year OS rate of the whole cohort was 90.6%, 80.0%, and 75.5%, respectively. The results of univariate and multivariate Cox regression analysis indicated that the primary site in parameningeal region, alveolar RMS histology, M1 stage, IRS stage 4, surgery, and chemotherapy were significant prognostic factors (all P<0.05). The performance of nomogram model was validated by discrimination and calibration, with AUC values of 1, 3, and 5 years OS of 0.843, 0.851, and 0.890, respectively.

Conclusion

We constructed a prognostic nomogram model for predicting the OS in HNRMS patients in children and adolescents and this model presented practical and applicable clinical value to predict survival when choosing treatment strategies.

A Rare Case Report of Intraosseous Spindle and Epithelioid Rhabdomyosarcoma With TFCP2 Rearrangement: A Pathological Diagnostic Conundrum and Literature Review

Rhabdomyosarcoma is a highly malignant tumor with striated muscle differentiation, which is histologically classified as alveolar, embryonal, pleomorphic, and spindle cell/sclerosing histological subtype. Rhabdomyosarcoma with TFCP2 rearrangement, which usually occurs in the bone, is a newly identified rare spindle and epithelioid rhabdomyosarcoma with characteristic clinicopathological features and molecular alterations. We report a 39-year-old female patient who underwent local excision of the mandibular lesion. Microscopically, the intraosseous tumor was composed of spindle-shaped, epithelioid, and rhabdomyoblastic cells with atypical nuclei and atypical mitotic figures. In addition, TFCP2 rearrangement was revealed by the fluorescence in situ hybridization. The tumor was thus correctly diagnosed as rhabdomyosarcoma with TFCP2 rearrangement. The patient was scheduled to undergo radiotherapy, and triple-agent chemotherapy after surgery, and no tumor recurrence or metastasis was detected during the 3-month postoperative follow up. Since this tumor is relatively rare and newly recognized, it can be easily misdiagnosed or missed and might be a conundrum of pathological diagnosis. Familiarity with its clinicopathological features and molecular alterations is essential for its correct diagnosis. Therefore, we summarized the clinicopathological, immunohistochemical, and molecular alterations of 43 cases of this rare rhabdomyosarcoma variant in the English-language literature. In addition, the differential diagnosis of this lesion is crucial either.

Primary cardiac rhabdomyosarcoma in a mitral valve involved with rheumatic disease

A 51-year-old female underwent emergency mitral valve replacement for mitral stenosis with an undetermined mass which was attached to the anterior mitral leaflet. Histopathological testing of the excised specimen confirmed the diagnosis of rheumatic mitral disease in combination with a primary rhabdomyosarcoma. Postoperative adjuvant chemotherapy with pazopanib hydrochloride was given. At 10 months of follow-up, repeated computed tomographic screening has not shown any signs of local recurrence or secondary metastases. The potential for the existence of primary rhabdomyosarcomas should be borne in mind when faced with undetermined masses on mitral leaflets, even in the presence of rheumatic disease.

Management of a pure uterine corpus rhabdomyosarcoma in a postmenopausal patient: A rare case report and review of the literature

Key Clinical Message

Rhabdomyosarcoma of the female genital tract often involves the vagina and cervix. It usually occurs in infants and children. Such tumors are uncommon in the uterus, especially in adults. Treatment options are based on studies of younger individuals.

Abstract

Rhabdomyosarcoma (RMS) is a malignant mesenchymal neoplasm with a tendency to differentiate into skeletal muscle cells. RMS is an aggressive tumor that tends to develop in children and younger patients. A vast majority of genital tract RMSs occur in the vagina and cervix. Such tumors rarely occur in adults. Usually, these tumors either occur as a component of a biphasic uterine tumor (carcinosarcoma or adenosarcoma) or can be a pure heterologous tumor. Pure uterine RMSs are extremely rare in adult patients and difficult to diagnose. Accurate diagnosis of these tumors depends on precise histopathological evaluation. The present report describes a rare case of embryonal RMS of the uterus in a postmenopausal female and explores the most recent literature. The aim is to strengthen the existing literature and aid clinicians in the management of similar cases. A 64-year-old postmenopausal female presented with a history of abdominal pain associated with abdominal distension, per vaginal bleeding, and foul-smelling discharge for 6 months. A transabdominal ultrasound revealed a bulky uterus with a well-circumscribed heterogeneous lesion. Histopathology confirmed the diagnosis of high-grade embryonal RMS within the corpus region of the uterus. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed, followed by adjuvant chemotherapy to prevent relapse of the disease. Six months after oncological care has passed, the patient remains symptoms-free without evidence of recurrence or metastasis.

Spindle cell embryonal rhabdomyosarcoma of the prostate in an adult patient: a case report and review of the literature

Rhabdomyosarcoma of the prostate is a rare mesenchymal tumor that originates from undifferentiated mesenchymal cells. Spindle cell rhabdomyosarcoma is a variant of embryonal rhabdomyosarcoma. The vast majority of these two pathological types occur in children, with only a few adult cases reported to date, and both are associated with poor clinical outcomes. We herein report a case involving a man in his early 40s with spindle cell embryonal rhabdomyosarcoma of the prostate. His chief complaint was difficult urination. The diagnosis was confirmed by puncture biopsy of the prostate, and pelvic lymph node metastasis was already present at the time of diagnosis. The patient underwent three courses of chemotherapy. However, his response to the treatment was very poor, and he died of the disease 4 months after diagnosis.

Rhabdomyosarcoma in Adults: De Novo or Conversion From Non-seminomas?

Rhabdomyosarcoma (RMS) is a highly sporadic, very aggressive, and fatal soft tissue tumor in adults. Although more common and treatable in the pediatric population, the occurrence of pleomorphic RMS in adults has a low incidence. Hence, it is not easy to treat. Surgery is the primary definitive treatment, along with radiation therapy, while adjuvant chemotherapy has recently gained popularity. We present an infrequent case of RMS in a patient with a recent history of mixed non-seminomatous germ-cell tumor testicular cancer. Therefore, it was challenging to treat the RMS as a new malignancy or as a recurrence of non-seminomatous testicular cancer. Our patient passed away, unfortunately, but we hope this case can help the minimal data in this regard in order to save more lives in the future.

Frontline and Relapsed Rhabdomyosarcoma (FAR-RMS) Clinical Trial: A Report from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG)

The Frontline and Relapsed Rhabdomyosarcoma (FaR-RMS) clinical trial is an overarching, multinational study for children and adults with rhabdomyosarcoma (RMS). The trial, developed by the European Soft Tissue Sarcoma Study Group (EpSSG), incorporates multiple different research questions within a multistage design with a focus on (i) novel regimens for poor prognostic subgroups, (ii) optimal duration of maintenance chemotherapy, and (iii) optimal use of radiotherapy for local control and widespread metastatic disease. Additional sub-studies focusing on biological risk stratification, use of imaging modalities, including [18F]FDG PET-CT and diffusion-weighted MRI imaging (DWI) as prognostic markers, and impact of therapy on quality of life are described. This paper forms part of a Special Issue on rhabdomyosarcoma and outlines the study background, rationale for randomisations and sub-studies, design, and plans for utilisation and dissemination of results.

The Capacity of Drug-Metabolising Enzymes in Modulating the Therapeutic Efficacy of Drugs to Treat Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a rare soft tissue sarcoma (STS) that predominantly affects children and teenagers. It is the most common STS in children (40%) and accounts for 5-8% of total childhood malignancies. Apart from surgery and radiotherapy in eligible patients, standard chemotherapy is the only therapeutic option clinically available for RMS patients. While survival rates for this childhood cancer have considerably improved over the last few decades for low-risk and intermediate-risk cases, the mortality rate remains exceptionally high in high-risk RMS patients with recurrent and/or metastatic disease. The intensification of chemotherapeutic protocols in advanced-stage RMS has historically induced aggravated toxicity with only very modest therapeutic gain. In this review, we critically analyse what has been achieved so far in RMS therapy and provide insight into how a diverse group of drug-metabolising enzymes (DMEs) possess the capacity to modify the clinical efficacy of chemotherapy. We provide suggestions for new therapeutic strategies that exploit the presence of DMEs for prodrug activation, targeted chemotherapy that does not rely on DMEs, and RMS-molecular-subtype-targeted therapies that have the potential to enter clinical evaluation.

Transforming Growth Factor Beta and Alveolar Rhabdomyosarcoma: A Challenge of Tumor Differentiation and Chemotherapy Response

Alveolar rhabdomyosarcoma (ARMS), an invasive subtype of rhabdomyosarcoma (RMS), is associated with chromosomal translocation events resulting in one of two oncogenic fusion genes, PAX3-FOXO1 or PAX7-FOXO1. ARMS patients exhibit an overexpression of the pleiotropic cytokine transforming growth factor beta (TGF-β). This overexpression of TGF-β1 causes an increased expression of a downstream transcription factor called SNAIL, which promotes epithelial to mesenchymal transition (EMT). Overexpression of TGF-β also inhibits myogenic differentiation, making ARMS patients highly resistant to chemotherapy. In this review, we first describe different types of RMS and then focus on ARMS and the impact of TGF-β in this tumor type. We next highlight current chemotherapy strategies, including a combination of the FDA-approved drugs vincristine, actinomycin D, and cyclophosphamide (VAC); cabozantinib; bortezomib; vinorelbine; AZD 1775; and cisplatin. Lastly, we discuss chemotherapy agents that target the differentiation of tumor cells in ARMS, which include all-trans retinoic acid (ATRA) and 5-Azacytidine. Improving our understanding of the role of signaling pathways, such as TGF-β1, in the development of ARMS tumor cells differentiation will help inform more tailored drug administration in the future.

Reappraisal of prognostic factors used in the European Pediatric Soft Tissue Sarcoma Study Group RMS 2005 study for localized rhabdomyosarcoma to optimize risk stratification and generate a prognostic nomogram

BACKGROUND

The objective of this study was to investigate the role of clinical factors together with FOXO1 fusion status in patients with nonmetastatic rhabdomyosarcoma (RMS) to develop a predictive model for event-free survival and provide a rationale for risk stratification in future trials.

METHODS

The authors used data from patients enrolled in the European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) RMS 2005 study (EpSSG RMS 2005; EudraCT number 2005-000217-35). The following baseline variables were considered for the multivariable model: age at diagnosis, sex, histology, primary tumor site, Intergroup Rhabdomyosarcoma Studies group, tumor size, nodal status, and FOXO1 fusion status. Main effects and significant second-order interactions of candidate predictors were included in a multiple Cox proportional hazards regression model. A nomogram was generated for predicting 5-year event-free survival (EFS) probabilities.

RESULTS

The EFS and overall survival rates at 5 years were 70.9% (95% confidence interval, 68.6%-73.1%) and 81.0% (95% confidence interval, 78.9%-82.8%), respectively. The multivariable model retained five prognostic factors, including age at diagnosis interacting with tumor size, tumor primary site, Intergroup Rhabdomyosarcoma Studies clinical group, and FOXO1 fusion status. Based on each patient's total score in the nomogram, patients were stratified into four groups. The 5-year EFS rates were 94.1%, 78.4%, 65.2%, and 52.1% in the low-risk, intermediate-risk, high-risk, and very-high-risk groups, respectively, and the corresponding 5-year overall survival rates were 97.2%, 91.5%, 74.3%, and 60.8%, respectively.

CONCLUSIONS

The results presented here provide the rationale to modify the EpSSG stratification, with the most significant change represented by the replacement of histology with fusion status. This classification was adopted in the new international trial launched by the EpSSG.

Statin-Sensitive Akt1/Src/Caveolin-1 Signaling Enhances Oxidative Stress Resistance in Rhabdomyosarcoma

Identifying the molecular mechanisms underlying radioresistance is a priority for the treatment of RMS, a myogenic tumor accounting for approximately 50% of all pediatric soft tissue sarcomas. We found that irradiation (IR) transiently increased phosphorylation of Akt1, Src, and Cav1 in human RD and RH30 lines. Synthetic inhibition of Akt1 and Src phosphorylation increased ROS levels in all RMS lines, promoting cellular radiosensitization. Accordingly, the elevated activation of the Akt1/Src/Cav1 pathway, as detected in two RD lines characterized by overexpression of a myristoylated Akt1 form (myrAkt1) or Cav1 (RDCav1), was correlated with reduced levels of ROS, higher expression of catalase, and increased radioresistance. We found that treatment with cholesterol-lowering drugs such as lovastatin and simvastatin promoted cell apoptosis in all RMS lines by reducing Akt1 and Cav1 levels and increasing intracellular ROS levels. Combining statins with IR significantly increased DNA damage and cell apoptosis as assessed by γ histone 2AX (γH2AX) staining and FACS analysis. Furthermore, in combination with the chemotherapeutic agent actinomycin D, statins were effective in reducing cell survival through increased apoptosis. Taken together, our findings suggest that the molecularly linked signature formed by Akt1, Src, Cav1, and catalase may represent a prognostic determinant for identifying subgroups of RMS patients with higher probability of recurrence after radiotherapy. Furthermore, statin-induced oxidative stress could represent a treatment option to improve the success of radiotherapy.

Case Report: Robotic pylorus-preserving pancreatoduodenectomy for periampullary rhabdomyosarcoma in a 3-year-old patient

Periampullary neoplasm is rare in pediatric patients and has constituted a strict indication for pancreatoduodenectomy (PD), which is a procedure sporadically reported in the literature among children. Robotic PD has been routinely performed for periampullary neoplasm in periampullary neoplasm, but only a few cases in pediatric patients have been reported. Here, we report the case of a 3-year-old patient with periampullary rhabdomyosarcoma treated with robotic pylorus-preserving PD and share our experience with this procedure in pediatric patients. A 3-year-old patient presented with obstructive jaundice and a mass in the pancreatic head revealed by imaging. A laparoscopic biopsy was performed. Jaundice progressed with abdominal pain and elevated alpha-amylase leading to urgent robotic exploration in which a periampullary neoplasm was revealed and pathologically diagnosed as rhabdomyosarcoma by frozen section examination. After pylorus-preserving PD, we performed a conventional jejunal loop following a child reconstruction, including an end-to-end pancreaticojejunostomy, followed by end-to-side hepaticojejunostomy and duodenojejunostomy. Delayed gastric emptying (DGE) presented with increasing drain from the nasogastric tube (NGT) a week after the surgery and improved spontaneously within 10 days. In a 13-month follow-up until the present, our case patient recovered well without potentially fatal complications, such as pancreatic fistula. Robotic PD in pediatric patients was safe and effective without intra- or postoperative complications.

Risk factors for neurocognitive impairment, emotional distress, and poor quality of life in survivors of pediatric rhabdomyosarcoma: A report from the Childhood Cancer Survivor Study

BACKGROUND

Prevalence and risk of poor psychological outcomes following rhabdomyosarcoma (RMS) are not well-established.

METHODS

Participants in this cross-sectional, case-control study (n = 713 survivors, 42.5% female; mean [SD] age, 30.5 [6.6] years; n = 706 siblings, 57.2% female; mean age, 32.8,[7.9] years) completed measures of neurocognition, emotional distress, and health-related quality of life (HRQOL). Multivariable logistic regression models identified treatments, health behaviors, and chronic conditions associated with impairment.

RESULTS

Relative to siblings, more survivors reported neurocognitive impairment (task efficiency: 21.1% vs. 13.7%, emotional regulation: 16.7% vs. 11.0%, memory: 19.3% vs. 15.1%), elevated emotional distress (somatic distress: 12.9% vs. 4.7%, anxiety: 11.7% vs. 5.9%, depression: 22.8% vs. 16.9%) and poorer HRQOL (physical functioning: 11.1% vs. 2.8%, role functioning due to physical problems: 16.8% vs. 8.2%, pain: 17.5% vs. 10.0%, vitality: 22.3% vs. 13.8%, social functioning: 14.4% vs. 6.8%, emotional functioning: 17.1% vs. 10.6%). Cranial radiation increased risk for impaired task efficiency (odds ratio [OR], 2.30; 95% confidence interval [CI], 1.14-4.63), whereas chest and pelvic radiation predicted increased risk of physical functioning (OR, 2.68; 95% CI, 1.16-6.21 and OR, 3.44; 95% CI, 1.70-6.95, respectively). Smoking was associated with impaired task efficiency (OR, 2.06; 95% CI, 1.14-3.70), memory (OR, 2.23; 95% CI, 1.26-3.95), anxiety (OR, 2.71; 95% CI, 1.36-5.41) and depression (OR, 1.77; 95% CI, 1.01-3.11). Neurologic conditions increased risk of anxiety (OR, 2.30; 95% CI, 1.04-5.10), and hearing conditions increased risk of depression (OR, 1.79; 95% CI, 1.05-3.03). Neurologic and hearing conditions, respectively, were associated with impaired memory (OR, 2.44; 95% CI, 1.20-4.95 and OR, 1.87; 95% CI, 1.05-3.35) and poor health perception (OR, 2.62; 95% CI, 1.62-1.28 and OR, 2.33; 95% CI, 1.34-4.06).

CONCLUSIONS

RMS survivors are at significant risk for poor psychological outcomes. Advancing therapies for local control, smoking cessation, and managing chronic medical conditions may mitigate poor outcomes following RMS.

Evaluation of clinical and imaging features for differentiating rhabdomyosarcoma from neuroblastoma in pediatric soft tissue

Background

In this study, we developed a nomogram predictive model based on clinical, CT, and MRI parameters to differentiate soft tissue rhabdomyosarcoma (RMS) from neuroblastoma (NB) in children preoperatively.

Materials and methods

A total of 103 children with RMS (n=37) and NB (n=66) were enrolled in the study from December 2012 to July 2023. The clinical and imaging data (assessed by two experienced radiologists) were analyzed using univariate analysis, and significant factors were further analyzed by multivariable logistic regression using the forward LR method to develop the clinical model, radiological model, and integrated nomogram model, respectively. The diagnostic performances, goodness of fit, and clinical utility of the integrated nomogram model were assessed using the area under the curve (AUC) of the receiver operator characteristics curve (ROC) with a 95% confidence interval (95% CI), calibration curve, and decision curve analysis (DCA) curves, respectively. Diagnostic efficacy between the model and radiologists' interpretations was examined.

Results

The median age at diagnosis in the RMS group was significantly older than the NB group (36.0 months vs. 14.5 months; P=0.003); the fever rates in RMS patients were significantly lower than in patients with NB (0.0% vs.16.7%; P=0.022), and the incidence of palpable mass was higher in patients with RMS compared with the NB patients (89.2% vs. 34.8%; P<0.001). Compare NB on image features: RMS occurred more frequently in the head and neck and displayed homogeneous density on non-enhanced CT than NB (48.6% vs. 9.1%; 35.3% vs. 13.8%, respectively; all P<0.05), and the occurrence of characteristics such as calcification, encasing vessels, and intraspinal tumor extension was significantly less frequent in RMS children compared to children with NB (18.9% vs. 84.8%; 13.5% vs. 34.8%; 2.7% vs. 50.0%, respectively; all P <0.05). Two, three, and four features were identified as independent parameters by multivariate logistic regression analysis to develop the clinical, radiological, and integrated nomogram models, respectively. The AUC value (0.962), calibration curve, and DCA showed that the integrated nomogram model may provide better diagnostic performance, good agreement, and greater clinical net benefits than the clinical model, radiological model, and radiologists' subjective diagnosis.

Conclusion

The clinical and imaging features-based nomogram has potential for helping radiologists distinguish between pediatric soft tissue RMS and NB patients preoperatively, and reduce unnecessary interventions.

Contemporary preclinical mouse models for pediatric rhabdomyosarcoma: from bedside to bench to bedside

Background

Rhabdomyosarcoma (RMS) is the most common pediatric soft-tissue malignancy, characterized by high clinicalopathological and molecular heterogeneity. Preclinical in vivo models are essential for advancing our understanding of RMS oncobiology and developing novel treatment strategies. However, the diversity of scholarly data on preclinical RMS studies may challenge scientists and clinicians. Hence, we performed a systematic literature survey of contemporary RMS mouse models to characterize their phenotypes and assess their translational relevance.

Methods

We identified papers published between 01/07/2018 and 01/07/2023 by searching PubMed and Web of Science databases.

Results

Out of 713 records screened, 118 studies (26.9%) were included in the qualitative synthesis. Cell line-derived xenografts (CDX) were the most commonly utilized (n = 75, 63.6%), followed by patient-derived xenografts (PDX) and syngeneic models, each accounting for 11.9% (n = 14), and genetically engineered mouse models (GEMM) (n = 7, 5.9%). Combinations of different model categories were reported in 5.9% (n = 7) of studies. One study employed a virus-induced RMS model. Overall, 40.0% (n = 30) of the studies utilizing CDX models established alveolar RMS (aRMS), while 38.7% (n = 29) were embryonal phenotypes (eRMS). There were 20.0% (n = 15) of studies that involved a combination of both aRMS and eRMS subtypes. In one study (1.3%), the RMS phenotype was spindle cell/sclerosing. Subcutaneous xenografts (n = 66, 55.9%) were more frequently used compared to orthotopic models (n = 29, 24.6%). Notably, none of the employed cell lines were derived from primary untreated tumors. Only a minority of studies investigated disseminated RMS phenotypes (n = 16, 13.6%). The utilization areas of RMS models included testing drugs (n = 64, 54.2%), studying tumorigenesis (n = 56, 47.5%), tumor modeling (n = 19, 16.1%), imaging (n = 9, 7.6%), radiotherapy (n = 6, 5.1%), long-term effects related to radiotherapy (n = 3, 2.5%), and investigating biomarkers (n = 1, 0.8%). Notably, no preclinical studies focused on surgery.

Conclusions

This up-to-date review highlights the need for mouse models with dissemination phenotypes and cell lines from primary untreated tumors. Furthermore, efforts should be directed towards underexplored areas such as surgery, radiotherapy, and biomarkers.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Rhabdomyosarcoma of the tongue in a neonatal calf

A newborn male Holstein calf developed a nodular enlargement at the tip of the tongue. Histopathological examination of the mass revealed predominant proliferating small, round, spindloid or polygonal neoplastic cells with scattered myoblast- and myotube-like cells and multinuclear giant cells. Phosphotungstic acid haematoxylin staining revealed cytoplasmic cross-striations in a few neoplastic cells. Neoplastic cells were immunopositive for vimentin, desmin, myoD1, myogenin, myoglobin and α-smooth muscle actin. The mass was diagnosed as embryonal rhabdomyosarcoma. To the best of our knowledge, this is the first reported case of bovine congenital lingual rhabdomyosarcoma, which is rare in animals.

Molecular Amplification and Cell Culturing Efficiency for Enteroviruses' Detection in Cerebrospinal Fluids of Algerian Patients Suffering from Meningitis

Enteroviruses (EVs) represent a major cause of viral meningitis, being responsible for nearly 1 billion infections each year worldwide. Several techniques were developed to obtain better diagnostic results of EV infections. Herein, we evaluated the efficiency of EV detection through isolation on both Rhabdomyosarcoma (RD) and Vero cell line cultures, conventional reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR. Thus, 50 cerebrospinal fluid (CSF) samples belonging to patients suspected to have viral meningitis in northern Algeria were collected, anonymously numbered from 1 to 50 and subjected to the above-mentioned techniques for EV detection. Using real-time RT-PCR, 34 CSF samples were revealed to be positive for viral origin of meningitis (68%). Thirteen of them were positive when the conventional RT-PCR was used (26%), and only three samples gave positive results when the cell culture technique was used (6%). Surprisingly, two cell culture-positive CSF samples, namely, 31 and 39, were negative using RT-PCR directly on the original samples. However, they turned to be positive when amplification was carried out on their corresponding cell culture supernatant. The cell-cultured viral isolates were then identified by sequencing their viral genome's VP1 regions. All of them were revealed to belong to the echovirus 27 strain. This investigation demonstrates that RT-PCR techniques are often more sensitive, accurate and much faster, providing reliable results within a clinically acceptable timeframe. However, viral isolation on cell cultures remains crucial to obtain enough viral load for serological tests or even to avoid the rare, but existing, false negative PCR.

Dedifferentiated Leiomyosarcoma of the Uterine Corpus with Heterologous Component: Clinicopathological Analysis of Five Consecutive Cases from a Single Institution and Comprehensive Literature Review

Dedifferentiation is a very rare phenomenon in uterine leiomyosarcoma (LMS). The aim of this study was to comprehensively analyze the clinicopathological characteristics of uterine dedifferentiated LMS (DDLMS). We reviewed electronic medical records and pathology slides from five patients with uterine DDLMS and performed immunostaining. The mean age of the patients was 56 years. Two patients presented with abdominal discomfort, while in three cases the uterine tumors were detected on routine medical examination. The mean size of the tumors was 17.0 cm. Four patients underwent hysterectomy. The initial stages were distributed as IB (2/5), IIIC (2/5), and IVC (1/5). Post-operative concurrent chemoradiation therapy, radiation therapy, and chemotherapy were administered in one, one, and two patients, respectively. Despite post-operative treatment, three patients developed metastatic recurrences in the abdominal and pelvic organs. Recurrence-free survival time ranged between 4 and 30 months. Histologically, the differentiated areas demonstrated the classic morphology of malignant smooth muscle differentiation, whereas the dedifferentiated areas resembled undifferentiated pleomorphic sarcoma and were characterized by large pleomorphic tumor cells admixed with haphazardly arranged atypical cells with marked nuclear pleomorphism. All cases also exhibited heterologous components, including chondrosarcoma (CSA; 3/5) and rhabdomyosarcoma (2/5). In two cases, the heterologous components were initially detected in primary tumors. In three cases, the primary tumors did not exhibit any dedifferentiated or heterologous components. Instead, more than half of the recurrent tumors consisted of heterologous components. Three cases showed a sharp demarcation between the LMS and CSA components, while in two cases the dedifferentiated area imperceptibly merged with the differentiated component. Immunostaining revealed that the dedifferentiated components exhibited a lack of desmin immunoreactivity in three of the four examined cases. A subset of uterine LMS represents various amounts and types of dedifferentiation and heterologous components in both primary and recurrent tumors. Routine recognition of DDLMS and distinction from its mimickers are required for accurate diagnosis and further characterization of these rare tumors.

Identification of common factors among fibrosarcoma, rhabdomyosarcoma, and osteosarcoma by network analysis

Sarcoma cancers are uncommon malignant tumors, and there are many subgroups, including fibrosarcoma (FS), which mainly affects middle-aged and older adults in deep soft tissues. Rhabdomyosarcoma (RMS), on the other hand, is the most common soft-tissue sarcoma in children and is located in the head and neck area. Osteosarcomas (OS) is the predominant form of primary bone cancer among young adults, primarily resulting from sporadically random mutations. This frequently results in the dissemination of cancer cells to the lungs, commonly known as metastasis. Mesodermal cells are the origin of sarcoma cancers. In this study, a rather radical approach has been applied. Instead of comparing homogenous cancer types, we focus on three main subtypes of sarcoma: fibrosarcoma, rhabdomyosarcoma, and osteosarcoma, and compare their gene expression with normal cell groups to identify the differentially expressed genes (DEGs). Next, by applying protein-protein interaction (PPI) network analysis, we determine the hub genes and crucial factors, such as transcription factors (TFs), affected by these types of cancer. Our findings indicate a modification in a range of pathways associated with cell cycle, extracellular matrix, and DNA repair in these three malignancies. Results showed that fibrosarcoma (FS), rhabdomyosarcoma (RMS), and osteosarcoma (OS) had 653, 1270, and 2823 differentially expressed genes (DEGs), respectively. Interestingly, there were 24 DEGs common to all three types. Network analysis showed that the fibrosarcoma network had two sub-networks identified in FS that contributed to the catabolic process of collagen via the G-protein coupled receptor signaling pathway. The rhabdomyosarcoma network included nine sub-networks associated with cell division, extracellular matrix organization, mRNA splicing via spliceosome, and others. The osteosarcoma network has 13 sub-networks, including mRNA splicing, sister chromatid cohesion, DNA repair, etc. In conclusion, the common DEGs identified in this study have been shown to play significant and multiple roles in various other cancers based on the literature review, indicating their significance.

Inflammatory Rhabdomyoblastic Tumor: Clinicopathologic and Molecular Analysis of 13 Cases

Inflammatory rhabdomyoblastic tumors (IRMTs) are newly recognized skeletal muscle tumors with uncertain malignant potential. We investigated 13 IRMTs using clinicopathologic, genetic, and epigenetic methods. The cohort included 7 men and 6 women, aged 23 to 80 years (median, 50 years), of whom 2 had neurofibromatosis type 1. Most tumors occurred in the deep soft tissues of the lower limbs, head/neck, trunk wall, and retroperitoneum/pelvis. Two tumors involved the hypopharyngeal submucosa as polypoid masses. Eight tumors showed conventional histology of predominantly spindled cells with nuclear atypia, low mitotic activity, and massive inflammatory infiltrates. Three tumors showed atypical histology, including uniform epithelioid or plump cells and mitotically active histiocytes. The remaining 2 tumors demonstrated malignant progression to rhabdomyosarcoma; one had additional IRMT histology and the other was a pure sarcoma. All 11 IRMTs without malignant progression exhibited indolent behavior at a median follow-up of 43 months. One of the 2 patients with IRMTs with malignant progression died of lung metastases. All IRMTs were positive for desmin and PAX7, whereas myogenin and MyoD1 were expressed in a subset of cases. Targeted next-generation sequencing identified pathogenic mutations in NF1 (5/8) and TP53 (4/8). All TP53 mutations co-occurred with NF1 mutations. TP53 variant allele frequency was much lower than that of NF1 in 2 cases. These tumors showed geographic (subclonal) strong p53 immunoreactivity, suggesting the secondary emergence of a TP53-mutant clone. DNA methylation-based copy number analysis conducted in 11 tumors revealed characteristic flat patterns with relative gains, including chromosomes 5, 18, 20, 21, and/or 22 in most cases. Widespread loss of heterozygosity with retained biparental copies of these chromosomes was confirmed in 4 tumors analyzed via allele-specific profiling. Based on unsupervised DNA methylation analysis, none of the 11 tumors tested clustered with existing reference entities but formed a coherent group, although its specificity warrants further study.

Bipolar Head Perforation With Rhabdomyosarcoma of the Thigh: A Case Report With Literature Review

Background/Aim

High complication rates during the perioperative management of sarcomas around the pelvis have been reported; however, few include the detailed clinical course or complications in the late postoperative period. Radiotherapy is a multidisciplinary strategy for treating sarcomas. However, irradiated bone and soft tissues show a permanent loss of repair and immunocompetence. We present a case of pleomorphic rhabdomyosarcoma of the thigh that resulted in acetabular collapse induced by radiation and intestinal perforation during long-term follow-up. Additionally, we discuss the risk factors for late complications and pelvic reconstruction methods.

Case Report

A 75-year-old man presented with a 1-month history of a recurring fever. Ten years prior, he was diagnosed with pleomorphic rhabdomyosarcoma of the right thigh and underwent a wide resection and bipolar hip arthroplasty, followed by chemotherapy and radiotherapy. Radiographs showed central dislocation of the bipolar head. Computed tomography revealed free air in the hip joint and thickening of the colon wall. Colonoscopy revealed displacement of the bipolar head into the colon wall. Colon resection and hip disarticulation were performed, as the bipolar head was contaminated with intestinal contents. Currently, he is able to walk stably with a walker, and there is no evidence of recurrence or metastasis of the tumor.

Conclusion

Irradiation of the periacetabular bone may induce resorptive destruction, resulting in future structural failure. Hardware should not be used for periacetabular bone reconstruction; the risk of pelvic organ damage should be considered when the acetabular collapse becomes deteriorated. Therefore, other reliable and permanent reconstruction options are required.

Successful management strategy for giant primary hepatic rhabdomyosarcoma in 15-year-old male: a case report

Primary hepatic rhabdomyosarcoma is an exceedingly rare type of sarcomas. A 15-year-old boy was admitted to the hospital with abdominal pain. Serial investigation showed a giant heterogeneous mass, with a diameter of 15 cm, located in the right lobe of the liver (segment 4a, 4b, 5, 6, 7, 8), with clear margins, non-homogeneous density in computerized tomography and the Positron Emission Tomography Scan Multi Slice revealed a peripherally slightly metabolically active hepatic mass (205 × 134 × 208 mm). Histopathological examination and the Immunohistochemical showed embryonal rhabdomyosarcoma. The management strategy involved multiple cycles of ifosfamide and doxorubicin and monitoring the tumor size, until the tumor size was suitable for the surgery. The management of hepatic rhabdomyosarcoma is a surgical challenge due to the late onset of symptoms, a limited number of reported cases, and poor prognosis. Surgical excision is the treatment of choice for primary hepatic rhabdomyosarcoma and combination between chemotherapy, surgery showed good results.

Diagnostic journey and multimodal management of a rare urogenital rhabdomyosarcoma with rectovaginal fistula in an adolescent: a case report

Introduction and importance

Rhabdomyosarcoma is a malignant tumour that originates from immature muscle cells and belongs to the category of soft-tissue sarcomas. It is predominantly diagnosed in children under the age of 6. This condition can manifest within the genitourinary tract and may exhibit non-specific symptoms such as changes in bowel habits and fever. Early detection and a comprehensive, multidisciplinary approach are essential to achieving more favourable outcomes. This report highlights an uncommon case of urogenital rhabdomyosarcoma in a 15-year-old girl, in addition to the presence of a rectovaginal fistula.

Case presentation

A 15-year-old girl with presented with fever, altered bowel habits, and a lump in her lower abdomen, abdominal discomfort, and incomplete bowel evacuation. She also had faecal discharge from the vagina. Diagnostic imaging and biopsy confirmed urogenital rhabdomyosarcoma with a rectovaginal fistula. The patient is currently undergoing induction chemotherapy and is scheduled for radiation therapy and surgery.

Clinical discussion

Rhabdomyosarcoma is a rare paediatric oncologic concern due to its aggressive nature and potential metastasis. The presentation varies based on age, tumour location, and metastasis presence. This patient presented with altered bowel habits, a pelvic mass and unusual feculent discharge, suggesting a rectovaginal fistula. Diagnostic imaging confirmed the diagnosis, and induction chemotherapy led to a positive response and reduced tumour size.

Conclusion

Urogenital rhabdomyosarcoma is an aggressive malignancy with non-specific symptoms, making early diagnosis challenging. An accurate diagnosis requires high suspicion, imaging, and a biopsy. Multidisciplinary management, including surgery, chemotherapy, and radiation therapy, improves outcomes and improves paediatric patients' prognosis and quality of life.

Significance of fusion status, Oberlin risk factors, local and maintenance treatment in pediatric and adolescent patients with metastatic rhabdomyosarcoma: Data of the European Soft Tissue Sarcoma Registry SoTiSaR

BACKGROUND

Outcome of primary metastatic rhabdomyosarcoma (RMS) is poor. Certain risk factors as fusion status, Oberlin score, and local treatment of primary tumor are known to influence prognosis.

PROCEDURE

Patients with metastatic RMS were treated according to Cooperative Weichteilsarkom Studiengruppe (CWS) guidance with chemotherapy (CHT), radiotherapy (RT) excluding total lung irradiation (TLI), complete resection of the primary tumor, and metastasectomy if possible. Kaplan-Meier estimators and Cox proportional hazard models were used to examine event-free survival (EFS) and overall survival (OS) involving also landmark analyses.

RESULTS

In the European Soft Tissue Sarcoma Registry SoTiSaR (2009-2018), 211 patients were analyzed. Many patients had fusion-positive alveolar RMS (n = 83; 39%). Median age was 9.4 years [0.1-19.7 years]. Treatment primarily consisted of CHT with CEVAIE (carboplatin, epirubicine, vincristine, actinomycin-D, ifosfamide, etoposide: 86%, other regimens: 14%), RT (71%), resection of primary tumor (37%), metastasectomy (19%), and lymph node sampling/dissection (21%). Maintenance treatment (MT) (oral trofosfamide, idarubicin, etoposide) was added in 74% of patients. Oberlin factors, fusion status, and MT were predictive for EFS and OS. MT with O-TIE was not improving outcome when adjusting for the immortal time bias. Local treatment of the primary tumor and radical irradiation (except TLI) improved EFS, not OS, when adjusting for the Oberlin score. Patients with fusion-negative alveolar RMS (n = 9) had an excellent outcome with a 5-year EFS and OS of 100%, compared to patients with embryonal RMS (49%/62%), PAX7- (22%/47%) and PAX3/FOXO1-positive ARMS (10/13%), respectively (p < .001).

CONCLUSIONS

Prognosis of metastatic RMS primarily depends on fusion status and Oberlin score. Fusion status needs to be considered in future trials to optimize treatment outcome. The role of radical irradiation needs further investigation.

Ergodicity Breaking and Self-Destruction of Cancer Cells by Induced Genome Chaos

During the progression of some cancer cells, the degree of genome instability may increase, leading to genome chaos in populations of malignant cells. While normally chaos is associated with ergodicity, i.e., the state when the time averages of relevant parameters are equal to their phase space averages, the situation with cancer propagation is more complex. Chromothripsis, a catastrophic massive genomic rearrangement, is observed in many types of cancer, leading to increased mutation rates. We present an entropic model of genome chaos and ergodicity and experimental evidence that increasing the degree of chaos beyond the non-ergodic threshold may lead to the self-destruction of some tumor cells. We study time and population averages of chromothripsis frequency in cloned rhabdomyosarcomas from rat stem cells. Clones with frequency above 10% result in cell apoptosis, possibly due to mutations in the BCL2 gene. Potentially, this can be used for suppressing cancer cells by shifting them into a non-ergodic proliferation regime.

PROGNOSTIC IMPLICATIONS OF PD-L1 EXPRESSION AND LOSS OF PTEN IN PATIENTS WITH RHABDOMYOSARCOMA, EWING'S SARCOMA AND OSTEOSARCOMA

BACKGROUND

In children, osteosarcoma (OS), Ewing's sarcoma (ES), and rhabdomyosarcoma (RMS) are the most common sarcomas. A link between the anti-programmed death ligand-1 PD-L1 and the tumor suppressor phosphatase and tensin homologue (PTEN) expression has been described in many tumors. The aim of this work is to determine clinicopathological relationships and the possible prognostic significance of PD-L1 and PTEN expression in rhabdomyosarcoma (RMS), Ewing's sarcoma (ES), and osteosarcoma (OS).

MATERIALS AND METHODS

Expression of PD-L1 and PTEN were examined by immunohistochemistry in 45 archival RMS, ES, and OS cases.

RESULTS

The positive expression of PD-L1 was found in 16.7% and 31.6% of ES and OS, respectively. The negative PD-L1 was related to a substantially longer survival in ES cases (p = 0.045), but positive PD-L1 expression was significantly associated with the increased tumor stage and vascular invasion in the OS cases (p = 0.005 and p = 0.002), respectively. On the other hand, PTEN loss was strongly associated with deep tumor, high tumor grade, and recurrence in RMS (p = 0.002, p = 0.045, and p = 0.026, respectively). However, PTEN loss was significantly absent in ES as tumor grade increased (p = 0.031). It is noteworthy that tumor recurrence, the loss of PTEN, and positive PD-L1 were all considered predictive factors in OS patients (p = 0.045, p = 0.032, and p = 0.02, respectively).

CONCLUSIONS

In children, OS and ES have positive PD-L1 expression, which has an independent unfavorable prognostic effect and raises the possibility of using PD-L1 as a therapeutic target. OS, ES, and RMS prognosis are all predicted by PTEN loss.

Clinicopathologic characteristics, treatment, prognosis and pregnancy outcomes in rhabdomyosarcoma of the uterine cervix: a case series

OBJECTIVES

In this retrospective observational study, cases from our institution were included and the published literature reviewed to investigate the diagnosis and prognosis of cervical rhabdomyosarcoma, a rare group of tumours.

MATERIAL AND METHODS

The clinicopathological data of 12 patients with cervical rhabdomyosarcoma (RMS) treated at the West China Second University Hospital of Sichuan University from January 2006 to May 2023 were collected, and their clinicopathological characteristics, diagnoses, treatments, prognoses and pregnancy outcomes were retrospectively analysed.

RESULTS

(1) Clinical characteristics: The ages of the 12 RMS patients ranged from 15 to 50 years, with a median age of 17 years. Five of the patients were adults, and seven were adolescents. The initial symptoms were vaginal bleeding in 5 patients, vaginal tissue prolapse in 6 patients, and abdominal pain and urinary frequency in 1 patient. Two patients were considered to have "cervical polyps" and underwent polypectomy at the other hospitals, but the cervical mass recurred soon thereafter. (2) Pathological features: The maximum tumour diameter ranged from 3 to 25 cm. The twelve cases of cervical RMS consisted of embryonal rhabdomyosarcoma (ERMS) in 7 adolescents, ERMS in 3 adults, and pleomorphic rhabdomyosarcoma (PRMS) in 2 adults. Immunohistochemical results showed the expression of one or more characteristic markers of RMS. We reclassified tumour stage according to the Intergroup Rhabdomyosarcoma Study (IRS) clinical group and tumour node metastasis (TNM) classification. (3) Treatment: Eight patients underwent radical surgery (66.7%, 8/12), including all 5 of the included adults and 3 of the adolescents, 2 of whom were treated 10 years ago. Conservative surgical resection was performed on four patients (33.3%, 4/12), all of whom were adolescents. Postoperative chemotherapy was given to all patients except one, but one patient who underwent radical surgery discontinued chemotherapy on her own without receiving a full course. Two of the ERMS patients underwent preoperative chemotherapy, and the lesions were significantly reduced. (4) Prognosis: One of the 12 patients with cervical RMS was lost to follow-up. Of the remaining 11 patients, 10 (including seven adolescents and three adults) survived tumour free (90.9%, 10/11), and 1 adult patient with existing pulmonary multiple metastases (IRS stage IV, T2N0M1) at the initial diagnosis survived 9 months with progression-free disease (9.1%, 1/11). The median survival time was 91 months (5 to 213 months). Among 4 patients receiving fertility-sparing management, 1 conceived and delivered successfully (25%).

CONCLUSIONS

The treatment of cervical RMS must take the patient's age and reproductive intent into account. The overall prognosis for cervical RMS in children and adolescents is good, and conservative surgical resection combined with chemotherapy is recommended to preserve fertility. The pregnancy outcome is also worth anticipating. For patients who have completed childbirth, radical surgery is preferred. Approaches to accurately assessing the patient's condition, grasping the indications and scope of surgery, and developing chemoradiotherapy regimens deserve further exploration.

Resection of a Large Growing Mediastinal Germ Cell Tumor Using a Multidisciplinary Approach

Mediastinal germ cell tumors (GCTs) are rare. Post-chemotherapy residual masses in patients with a nonseminomatous GCT require resection. A patient with a large mediastinal GCT involving the left subclavian artery, superior vena cava (SVC) and hilum of the right lung is presented. Despite a biochemical response to chemotherapy, the tumor enlarged on serial imaging. With guidance from medical oncology, a multidisciplinary surgical team, including cardiac anesthesia, cardiac surgery and thoracic surgery resected the tumor with a staged reconstruction of the SVC. The procedure was well tolerated and yielded clear margins. The final pathology showed a significant associated component of rhabdomyosarcoma.

Fusion-negative rhabdomyosarcoma 3D organoids to predict effective drug combinations: A proof-of-concept on cell death inducers

Rhabdomyosarcoma (RMS) is the main form of pediatric soft-tissue sarcoma. Its cure rate has not notably improved in the last 20 years following relapse, and the lack of reliable preclinical models has hampered the design of new therapies. This is particularly true for highly heterogeneous fusion-negative RMS (FNRMS). Although methods have been proposed to establish FNRMS organoids, their efficiency remains limited to date, both in terms of derivation rate and ability to accurately mimic the original tumor. Here, we present the development of a next-generation 3D organoid model derived from relapsed adult and pediatric FNRMS. This model preserves the molecular features of the patients' tumors and is expandable for several months in 3D, reinforcing its interest to drug combination screening with longitudinal efficacy monitoring. As a proof-of-concept, we demonstrate its preclinical relevance by reevaluating the therapeutic opportunities of targeting apoptosis in FNRMS from a streamlined approach based on transcriptomic data exploitation.

[Clinical analysis of 5 adult laryngeal rhabdomyosarcoma]

Objective:To explore the clinical manifestations,the type of pathology, treatment and prognosis of laryngeal rhabdomyosarcoma, and to enhance the understanding of the clinical characteristics of the disease, while improving the diagnosis rateand reducing the misdiagnosis rate, in order to explore effective diagnosis and treatment methods. Methods:A retrospective analysis was conducted on the clinical data of 5 cases of laryngeal rhabdomyosarcoma treated in the First Affiliated Hospital of Zhengzhou University from May 2015 to May 2021. Results:All 5 cases of laryngeal rhabdomyosarcoma were misdiagnosed in the early stage. with tumors mostly occurring in the vocal cords and appearing as smooth mass. The clinical symptoms were mostly hoarseness. According to pathological classification, three cases were embryonic type, one case was polymorphic type, and one case was spindle type.Three patients died due to tumor recurrence, one patient had multiple systemic metastases, and another patient who underwent surgical resection in the early stage and supplemented with postoperative radiotherapy and chemotherapyhas been followed up to date without recurrence. Conclusion:Laryngeal rhabdomyosarcoma has low incidence rate, high malignancy degree and poor prognosis. It is easy to be misdiagnosed as a benign mass. Extensive surgical resection combined with radiotherapy and chemotherapy should be performed as soon as possible after diagnosis.

Primary Gastric Rhabdomyosarcoma

Primary gastric rhabdomyosarcoma is extremely rare. An 87-year-old man visited our clinic with a chief complaint of abdominal pain. Computed tomography (CT) and 18F-fluorodeoxyglucose positron emission tomography-CT revealed a massive tumor originating from the muscularis propria of the stomach along with splenic vein tumor thrombosis. We diagnosed the patient with primary gastric rhabdomyosarcoma by an endoscopic ultrasound-guided fine-needle aspiration/biopsy.

Prognosis of children and young adults with newly diagnosed rhabdomyosarcoma metastatic to bone marrow treated on Children's Oncology Group studies

BACKGROUND

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Metastatic disease occurs in 16% of all RMS cases and has a poor prognosis. There are limited studies examining the outcomes specific to patients with RMS metastatic to bone marrow despite an incidence of 6% at diagnosis. Our study aims to document the outcomes, prognostic factors, and clinical courses of children presenting with RMS metastatic to bone marrow treated on Children's Oncology Group (COG) cooperative trials.

METHODS

We performed a retrospective analysis of the patients diagnosed with RMS metastatic to bone marrow between 1997 and 2013 enrolled on one of four COG RMS clinical trials of D9802, D9803, ARST0431, and ARST08P1.

RESULTS

We identified 179 cases with RMS metastatic to bone marrow. Patients had a median age of 14.8 years, 58% were male, predominantly alveolar histology (76%), extremity was the most common primary site (32%), and 87% had metastatic disease to additional sites; 83% (n = 149) received radiation as a treatment modality. The 3- and 5-year event-free survival was 9.4% and 8.2%, respectively. The 3- and 5-year overall survival was 26.1% and 12.6%, respectively. Age ≥10 years, alveolar histology, FOXO1 fusion presence, unfavorable primary location, higher Oberlin score, and lack of radiation were identified as poor prognostic/predictive characteristics.

CONCLUSIONS

This study represents the largest analysis of RMS metastatic to bone marrow, defining the poor prognostic outcome for these patients. These patients may be eligible for therapy deintensification or early pursuit of novel treatments/approaches that are desperately needed.

Expression of NKX2.2 in Non-Ewing Tumors With Round Cell Morphology

Background Round cell sarcomas pose diagnostic challenges due to overlapping histopathological features, necessitating precise immunohistochemical markers for accurate categorization. NKX2.2 has emerged as a sensitive diagnostic tool, particularly in Ewing sarcoma. This study extends this understanding to various round-cell sarcomas, shedding light on the potential diagnostic utility of NKX2.2 beyond its established role. The nuanced exploration of NKX2.2 expression aims to enhance diagnostic strategies, prognostic assessments, and therapeutic developments in the landscape of sarcoma research. Methodology Cases were retrieved from the surgical pathology and consultation files of Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, Pakistan. Representative hematoxylin and eosin-stained slides of six different types of already confirmed tumors, including lymphoblastic lymphoma, neuroblastoma, rhabdomyosarcoma, synovial sarcoma, Wilms tumor, and Ewing sarcoma, were reviewed by a panel of pathologists. Immunohistochemistry, utilizing a rabbit anti-NKX2.2 monoclonal antibody, was performed on formalin-fixed paraffin-embedded tissue sections. The presence of NKX2.2 was defined as moderate or high nuclear immunoreactivity in at least 5% of cells. Results The histopathological examination revealed characteristic features in each sarcoma subtype, aligning with established diagnostic criteria. In Lymphoblastic lymphoma, T-cell lineage was confirmed through TdT expression, while the atypical finding of focal NKX 2.2 expression hinted at genetic diversity. Neuroblastoma exhibited the expected salt and pepper chromatin pattern, with NKX 2.2 expression raising questions about its prognostic significance. Rhabdomyosarcoma presented primitive cells expressing desmin, and NKX 2.2 focal expression echoed previous subtype-associated studies. Synovial sarcoma displayed both monophasic and biphasic growth patterns and TLE1 expression, with NKX 2.2 variation suggesting tumor heterogeneity. In Wilms tumor, the characteristic WT1 expression was observed, while NKX2.2's absence reaffirmed its irrelevance in this context. Ewing sarcoma displayed the anticipated homogenous cell population, strong NKX2.2 expression, and CD99 positivity across various sites. Furthermore, age and gender impact on this range of sarcomas found no significant relation with an expression of NKX2.2. Conclusion In conclusion, the diverse expression profiles of diagnostic markers discovered in this study, particularly the atypical expression of NKX2.2 beyond its established role in Ewing sarcoma, signify a significant advancement. This unique finding accentuates the potential diagnostic importance of NKX2.2 in various sarcomas, presenting a novel dimension to our understanding of these malignancies.

Piezo1 facilitates optimal T cell activation during tumor challenge

Functional effector T cells in the tumor microenvironment (TME) are critical for successful anti-tumor responses. T cell anti-tumor function is dependent on their ability to differentiate from a naïve state, infiltrate into the tumor site, and exert cytotoxic functions. The factors dictating whether a particular T cell can successfully undergo these processes during tumor challenge are not yet completely understood. Piezo1 is a mechanosensitive cation channel with high expression on both CD4+ and CD8+ T cells. Previous studies have demonstrated that Piezo1 optimizes T cell activation and restrains the CD4+ regulatory T cell (Treg) pool in vitro and under inflammatory conditions in vivo. However, little is known about the role Piezo1 plays on CD4+ and CD8+ T cells in cancer. We hypothesized that disruption of Piezo1 on T cells impairs anti-tumor immunity in vivo by hindering inflammatory T cell responses. We challenged mice with T cell Piezo1 deletion (P1KO) with tumor models dependent on T cells for immune rejection. P1KO mice had the more aggressive tumors, higher tumor growth rates and were unresponsive to immune-mediated therapeutic interventions. We observed a decreased CD4:CD8 ratio in both the secondary lymphoid organs and TME of P1KO mice that correlated inversely with tumor size. Poor CD4+ helper T cell responses underpinned the immunodeficient phenotype of P1KO mice. Wild type CD8+ T cells are sub-optimally activated in vivo with P1KO CD4+ T cells, taking on a CD25loPD-1hi phenotype. Together, our results suggest that Piezo1 optimizes T cell activation in the context of a tumor response.

Differentiation-dependent chromosomal organization changes in normal myogenic cells are absent in rhabdomyosarcoma cells

Myogenesis, the progression of proliferating skeletal myoblasts to terminally differentiated myotubes, regulates thousands of target genes. Uninterrupted linear arrays of such genes are differentially associated with specific chromosomes, suggesting chromosome specific regulatory roles in myogenesis. Rhabdomyosarcoma (RMS), a tumor of skeletal muscle, shares common features with normal muscle cells. We hypothesized that RMS and myogenic cells possess differences in chromosomal organization related to myogenic gene arrangement. We compared the organizational characteristics of chromosomes 2 and 18, chosen for their difference in myogenic gene arrangement, in cultured RMS cell lines and normal myoblasts and myotubes. We found chromosome-specific differences in organization during normal myogenesis, with increased area occupied and a shift in peripheral localization specifically for chromosome 2. Most strikingly, we found a differentiation-dependent difference in positioning of chromosome 2 relative to the nuclear axis, with preferential positioning along the major nuclear axis present only in myotubes. RMS cells demonstrated no preference for such axial positioning, but induced differentiation through transfection of the pro-myogenic miRNA miR-206 resulted in an increase of major axial positioning of chromosome 2. Our findings identify both a differentiation-dependent, chromosome-specific change in organization in normal myogenesis, and highlight the role of chromosomal spatial organization in myogenic differentiation.

Inhibition of NAD+-Dependent Metabolic Processes Induces Cellular Necrosis and Tumor Regression in Rhabdomyosarcoma Models

PURPOSE

Deregulated metabolism in cancer cells represents a vulnerability that may be therapeutically exploited to benefit patients. One such target is nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD+ salvage pathway. NAMPT is necessary for efficient NAD+ production and may be exploited in cells with increased metabolic demands. We have identified NAMPT as a dependency in rhabdomyosarcoma (RMS), a malignancy for which novel therapies are critically needed. Here we describe the effect of NAMPT inhibition on RMS proliferation and metabolism in vitro and in vivo.

EXPERIMENTAL DESIGN

Assays of proliferation and cell death were used to determine the effects of pharmacologic NAMPT inhibition in a panel of ten molecularly diverse RMS cell lines. Mechanism of the clinical NAMPTi OT-82 was determined using measures of NAD+ and downstream NAD+-dependent functions, including energy metabolism. We used orthotopic xenograft models to examine tolerability, efficacy, and drug mechanism in vivo.

RESULTS

Across all ten RMS cell lines, OT-82 depleted NAD+ and inhibited cell growth at concentrations ≤1 nmol/L. Significant impairment of glycolysis was a universal finding, with some cell lines also exhibiting diminished oxidative phosphorylation. Most cell lines experienced profound depletion of ATP with subsequent irreversible necrotic cell death. Importantly, loss of NAD and glycolytic activity were confirmed in orthotopic in vivo models, which exhibited complete tumor regressions with OT-82 treatment delivered on the clinical schedule.

CONCLUSIONS

RMS is highly vulnerable to NAMPT inhibition. These findings underscore the need for further clinical study of this class of agents for this malignancy.

A systematic review of the prevalence of pathogenic or likely pathogenic germline variants in individuals with FOXO1 fusion-positive rhabdomyosarcoma

Several cancer predisposition syndromes (CPS) are reported to predispose to rhabdomyosarcoma, most frequently in children with embryonal rhabdomyosarcoma. There are lingering questions over the role of CPS in individuals with alveolar rhabdomyosarcoma (ARMS), which are frequently driven by FOXO1 fusion oncoproteins. We conducted a systematic review to identify patients with FOXO1 fusion-positive ARMS (FP-ARMS) who underwent germline DNA sequencing. We estimated the prevalence of pathogenic/likely pathogenic (P/LP) variants in cancer predisposing genes (CPGs) and of CPSs. We included 19 publications reporting on 191 patients with FP-ARMS. P/LP variants in CPGs were identified in 26/191 (13.6%) patients, nine (4.9%) of which were associated with a CPS diagnosis. Evidence for causal associations between CPSs and FP-ARMS could not be assessed with available data from this review. Only one patient was affected with a CPS known to predispose to rhabdomyosarcoma, Li-Fraumeni syndrome. Typical CPS associations with rhabdomyosarcoma are rare, but not nonexistent, in patients with FP-ARMS. FOXO1 fusion status, alone, is insufficient for clinicians to rely on to distinguish between patients with/without CPS.

Common queries in managing rhabdomyosarcoma in low- and middle-income countries: An Indo-North American collaboration

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma among children and adolescents. The management of RMS involves risk stratification of the patients based on various clinicopathological characteristics. The multimodality treatment approach requires chemotherapy, surgery, and/or radiation. The treatment of RMS necessitates the involvement of multiple disciplines, such as pathology, pediatric oncology, surgery, and radiation oncology. The disease heterogeneity, molecular testing, evolving treatment regimens, and limited resources are some of the challenges faced by clinicians while treating a patient with RMS in low- and middle-income countries (LMICs). In this review, we endeavor to bring experts from varying fields to address clinicians' common questions while managing a child or adolescent with RMS in LMICs. This review is most applicable to level 2 centers in LMICs as per the levels of services described by the Adapted Treatment Regimens Working Group of the Pediatric Oncology in Developing Countries committee of the International Society of Pediatric Oncology.