Five patients received a matched targeted therapy based on the molecular profiling results.

Assessment of ITH using the Shannon diversity index score. Box plots show the distribution of ITH scores (y-axis), in which each dot corresponds to an individual tumor sample. The ITH scores were assessed across sarcoma subtypes, disease status, and tumor location, with meaningful differences observed in osteosarcoma (OS) and Ewing sarcoma (EW) but not in RMS or SS. ITH distribution stratified by (A) tumor location in OSs and (B) disease status in EWs.

Abstract Sarcomas in pediatric and adolescent–young adult (AYA) populations represent rare and biologically heterogeneous tumors with complex genetic underpinnings. Genomic profiling reveals subtype-specific alterations and therapeutic targets. Such tumors still represent an unmet clinical need due to limited treatment options and poorer outcomes, especially in advanced stages. Here, we present the SAR-GEN2016 and SAR-GEN_ITA clinical trials, conducted across 12 Italian centers, which enrolled 201 patients, including 158 bone and soft-tissue sarcoma samples collected at diagnosis or relapse. Whole-exome sequencing was successfully performed on 120 tumor samples. The most representative histotypes were osteosarcoma (n = 53), Ewing sarcoma (n = 39), rhabdomyosarcoma (n = 13), and synovial sarcoma (n = 5), and the genomic analyses were mainly focused on these subtypes. Overall, our cohort showed genomic differences between subtypes, highlighting how genomic complex sarcomas and fusion-driven sarcomas are distinct entities. The genomic complex histotypes, such as osteosarcoma, were characterized by a lower tumor mutational burden (TMB) and higher copy-number variation burden with enrichment of the CN2 signature. Recurrent and metastatic Ewing sarcomas have a higher TMB compared with treatment-naïve primary tumors, along with increased intratumoral heterogeneity. Oncogenic pathway analyses revealed dysregulation of the RTK–RAS and NOTCH pathways across subtypes, particularly in metastatic and recurrent tumors. In 71 of 120 analyzed samples (59%), at least one potentially actionable genomic alteration was identified, and 16% of those patients with relapsed disease received a matched targeted therapy based on the molecular profiling results. All findings were classified as ESCAT tier II or III. Our findings support the value of integrating genomic and clinical data to accelerate translational research in rare tumors. Significance: Pediatric and AYA sarcomas are rare with poor outcomes in advanced stages and limited treatment options. Through the SAR-GEN2016 and SAR-GEN_ITA multicenter trials, we performed whole-exome sequencing on 120 tumor samples with matched normal tissue from 158 patients with bone and soft-tissue sarcoma. Our integrative genomic analysis supports the genomic stratification and precision oncology in rare pediatric sarcomas.

Oncogenic signaling pathways. A–D, Mirrored circular bar plots depict the overall enrichment of oncogenic pathways in osteosarcoma (OS; A), Ewing sarcoma (EW; B), RMS (C), and SS (D). Each bar represents a single pathway, with the height indicating the proportion of samples harboring corresponding somatic alterations. Somatic variants are shown in yellow and CNVs in light blue, with the corresponding percentage of affected samples. E and F, The heatmaps provide a detailed view of (E) variants and (F) CNVs in genes of each pathway stratified by disease status and, grouped by disease subtype. Top color bar indicates disease status. Bar plots on the right represent the proportion of each alteration type across pathways, cells, and corresponding color code.

CNV across sarcoma subtypes. A, CNV burden is shown with a box plot highlighting significant differences across all tumor samples from osteosarcoma (OS), Ewing sarcoma (EW), RMS, and SS, without stratification by disease status. A statistically significant difference was observed between EW and OS samples (two-tailed Wilcoxon test). B–D, Recurrent and significant CNVs were identified in OS and EW samples using GISTIC2 for primary (B and C) and metastatic (D) tumors. The cytobands are visualized using the R package maftools. Blue bars indicate deletions, red bars indicate amplifications, and gray bars represent nonsignificant CNVs. The G-score represents the amplitude and frequency of the CNVs across tumors of interest. E, Distribution of CN signatures across the cohorts, stratified by disease status for each tumor subtype. Left, signature names. Each dot represents a mutational signature. The color of the dot indicates the number (N) of samples harboring the signature, whereas the size of the dot reflects the percentage of samples carrying that signature. Signatures are grouped horizontally based on their classification and vertically by disease. The color bar at the bottom indicates the disease status.

OBJECTIVES:The death of a child from cancer is a devastating event with long-term psychological and social consequences for parents. While bereavement support is increasingly recognised as a standard of care in paediatric oncology, structured programmes remain limited and heterogeneous. METHODS:We conducted a cross-sectional survey of bereaved parents of paediatric oncology patients treated at our institution. A structured questionnaire, developed by a multidisciplinary team, explored experiences with bereavement initiatives and preferences for supportive activities. RESULTS:Of 156 questionnaires distributed, 74 were returned (47% response rate). Mothers completed 51% of the surveys, fathers 35% and both parents jointly 14%. Although 70% of parents reported no perceived need for formal bereavement support, 56% found volunteer activities and 62% ongoing contact with healthcare staff to be helpful. Preferred support options included counselling with a psychologist (38%), commemorative ceremonies (34%), peer groups (30%) and self-help groups (26%). Parents bereaved for more than 3 years expressed greater interest in peer meetings and contact with clinicians. No significant gender differences were observed. CONCLUSIONS:Parental bereavement needs are frequently underestimated and may extend beyond traditional counselling. A proactive and diversified model-integrating psychological care, peer mentorship and structured contact with healthcare teams-should be systematically offered to improve adaptation and reduce isolation among bereaved parents.

Details of sample according to histotypes.

INTRODUCTION:Ewing sarcoma (ES) is a malignant bone tumor with high relapse rates, especially in multi-metastatic disease despite multimodal treatment. The role of maintenance therapy in ES remains undefined. We systematically reviewed clinical trial data to assess the feasibility and rationale for maintenance therapy in localized and metastatic disease, with the aim to help selecting drugs to introduce as maintenance therapy within the trial. METHODS:A PubMed search identified studies evaluating maintenance or metronomic therapy in ES and other pediatric sarcomas published between January 1990 and January 2020. Inclusion of articles required clinical use of maintenance therapy in pediatric (Ewing) sarcoma; case reports, preclinical studies, reviews, and phase I trials were excluded. A second PubMed search (February 2020-June 2025) updated the evidence base. Data on study design, patient characteristics, treatment regimens, and outcomes were extracted. RESULTS:Of 3040 records identified in the first search, 20 were included: 11 included ES patients, 9 in other pediatric sarcomas. The update yielded 9 additional studies (3 ES, 6 other sarcomas). Vinorelbine, alone or combined with low-dose cyclophosphamide, was most frequently investigated, mainly in heavily pretreated relapsed or refractory ES patients, showing modest clinical activity. Strongest evidence derived from rhabdomyosarcoma (RMS) patients, where the randomized EpSSG RMS 2005-trial demonstrated improved long-term survival with vinorelbine/cyclophosphamide maintenance. CONCLUSION:Vinorelbine plus low-dose cyclophosphamide represent a rational backbone for ES maintenance therapy, supported by evidence in RMS and limited ES data. Ongoing international efforts will define their clinical role when given for 6 months. Future studies should eventually clarify optimal duration, alternative agents, and long-term safety.

Significant cytobands identified in osteosarcoma (primary and recurrent) and Ewing’s sarcoma (primary, recurrent, metastasis) with the respective genes

Clinical and sample overview of Sargen and Sargen-ITA patients

OBJECTIVES:The association between exposure to dinutuximab beta (DB) and event-free survival (EFS) or overall survival (OS) of neuroblastoma patients was assessed using data collected during three clinical trials (five cohorts). METHODS:A systematic review (March 2026) was conducted to identify relevant studies (prospective; registered DB indication and posology). Patient-level information on outcomes and their predictors was extracted from study reports. Because of immortal-time and reverse causation biases, survival was examined among patients who were event-free at their end-of-treatment (EOT) date (i.e., last dose + 25 days). To address selection bias, stabilised inverse-probability weights were estimated, and weighted post-EOT survival models were fitted. RESULTS:Of 665 patients, 98 had relapse or progression before EOT. The median duration of follow-up in the post-EOT cohort was 3.78 years. The total number of cycles was independently associated with both EFS (HR = 0.80, 95% CI: 0.70-0.90 per cycle, p < 0.001) and OS (HR = 0.78, 95% CI: 0.68-0.90 per cycle, p < 0.001). With each treatment cycle, post-EOT hazard of an EFS event decreased by 20% (95% CI: 10%-30%) and hazard of death decreased by 22% (95% CI: 10%-32%). The results were consistent across most sensitivity analyses (e.g., excluding IL-2 recipients, restricting to frontline maintenance immunotherapy, alternative specifications and exposure metrics), but not among patients with relapsed or refractory neuroblastoma. In a target-trial emulation (5 cycles vs. <5 cycles), associations were significant for EFS (HR = 0.46, 95% CI: 0.32-0.66, p < 0.001) and OS (HR = 0.44, 95% CI: 0.28-0.67, p < 0.001). CONCLUSIONS:Greater prior exposure to DB, particularly a higher number of treatment cycles, was associated with better post-EOT EFS and OS. The study did not estimate an on-treatment causal effect of DB, and the residual confounding cannot be fully excluded. Prior treatment exposure may help inform post-treatment risk stratification.

INTRODUCTION:Rhabdomyosarcoma is a highly chemosensitive tumor; however, high-risk and metastatic cases require more effective systemic treatments. This study evaluates the feasibility and efficacy of the "VIVA" regimen (vinorelbine-ifosfamide-vincristine-actinomycin D), which incorporates weekly vinorelbine into the induction phase of standard therapy. METHODS:Between 2020 and 2025, 45 patients (median age 14 years) with high-risk or metastatic rhabdomyosarcoma were treated at the Pediatric Unit of the Istituto Nazionale Tumori in Milan. The VIVA regimen added intravenous vinorelbine (25 mg/m2) on Days 8 and 15 of the standard 3-week IVA cycle. Treatment included nine induction cycles followed by 6-12 months of maintenance therapy (vinorelbine and oral cyclophosphamide), alongside multidisciplinary local control. RESULTS:Forty patients (89%) completed the planned nine VIVA cycles; five discontinued early due to disease progression. Among 41 evaluable patients, the overall response rate after three cycles was 95%. The estimated 3-year event-free survival (EFS) and overall survival (OS) rates were 68.0% and 78.6%, respectively. Myelotoxicity was the main side effect: grade ≥ 3 neutropenia, thrombocytopenia, and anemia occurred in 70%, 7%, and 21% of cycles, respectively. Granulocyte-colony-stimulating factor (G-CSF) was administered in 51% of cycles. Overall, 30% of the cycles required either a reduction or the omission of vinorelbine administration. Notably, 68% of patients required either no modifications (24%) or modifications in fewer than 25% of doses (44%). CONCLUSIONS:Integrating vinorelbine into the intensive induction phase proved feasible with an acceptable toxicity profile and high response rates. Further investigations are needed to define the long-term efficacy of this promising intensive regimen.

Overview of SAR-GEN2016 and SAR-GEN_ITA prospective multicentric trials. A, Workflow of the clinical trials, illustrating the process from patient enrollment through sample collection, genomic profiling, and analysis, to the multidisciplinary discussion at the MTB for therapeutic decision-making, with excluded samples indicated at each stage. B, Combination of percent stacked barcharts and box plot, from left to right: number of samples for each sarcoma subtype, tissue type of the biopsy (fresh or FFPE), disease status at the moment of the surgical procedure (primary, recurrent, and metastasis), purity of the tumor calculated after sequencing, and sex and age of the samples. EW, Ewing sarcoma; NA, not available; OS, osteosarcoma. [A, Created in BioRender. Grieco, M. (2025) https://BioRender.com/c7w0fbz.]

Genomic landscape of the four sarcoma subtypes. A and B, Box plots show the distribution of TMB on the y-axis, in which each dot represents an individual tumor sample. The horizontal dotted line at 1 mutation per megabase (mut/Mb) denotes the threshold used to separate lowly and highly mutated tumors. A, TMB distribution across all tumor samples of osteosarcoma (OS), Ewing sarcoma (EW), RMS, and SS. Statistically significant difference was observed between OS and EW samples (two-tailed Wilcoxon test). B, TMB distribution stratified by disease status (primary, recurrent, and metastasis) within the EW cohort. Significant differences were observed between primary and recurrent tumors (two-tailed Wilcoxon test) and between primary and metastatic tumors (two-tailed Wilcoxon test). C–F, Bar plots summarizing the top 25 mutated genes for each sarcoma subtypes, based on all tumor samples and without stratification by disease status. Genes are listed on the left side of each plot, with the corresponding percentage of mutated samples shown on the right. The percentages represent the number of unique samples harboring a mutation divided by the total number of samples in each sarcoma subtype (OS = 53, EW = 39, RMS = 13, and SS = 5). The x-axis shows the total number of mutations identified per gene. Color code represents the type of variants. G, Summary of the SBS and small indel signatures, stratified by disease status for each tumor subtype. On the left, the signature names. Each dot represents a mutational signature. The color of the dot (N) indicates the number of samples in which the signature is present, whereas the dot size represents the percentage of samples carrying that signature within that cohort. Signatures are grouped horizontally based on their classification and vertically by disease. The color bar at the bottom indicates the disease status.

ESMO Scale for Clinical Actionability of molecular Targets (ESCAT)

Background Atypical cartilaginous tumors (ACT) are low-grade cartilaginous lesions of the appendicular skeleton with debated diagnostic and therapeutic management. Methods The Italian Sarcoma Group (ISG) conducted a multidisciplinary consensus process involving 61 experts from six specialties across 22 institutions. A narrative literature review informed key questions discussed during an in-person consensus meeting, and agreement was assessed through structured voting. Results Six consensus statements were developed: three on diagnosis, two on treatment, and one on active surveillance and follow-up. Biopsy was recommended selectively in the presence of aggressive or equivocal radiological features. Active surveillance was endorsed for selected patients, while intralesional curettage remains the preferred surgical option when treatment is indicated. Structured follow-up protocols were proposed. Conclusions This consensus provides practical recommendations for the management of ACT, supporting imaging-driven decision-making and active surveillance in appropriate cases.

BackgroundWith the rapid progress of molecular medicine, new target therapies for solid tumors have become available, leading to the creation of molecular tumor boards (MTBs) designated to evaluate potential individualized treatment options. Unlike other solid or liquid tumors, there is no standard and customized tool to analyze sarcoma. We analyzed the organization of MTB in referral centers for sarcomas treatment in Italy.Materials and methodsA 30-question survey was designed in 2021 by the Regina Elena National Cancer Institute and distributed among Italian referral centers for pediatric and adult sarcomas. This survey was developed as part of Alliance Against Cancer (Alleanza Contro il Cancro, ACC) project to provide a descriptive analysis of the availability and organization of MTBs as well as the propensity to offer genomic profiling to sarcoma patients.ResultsA total of 6 out of 10 centers contacted answered the survey, and all stating centers declared to have an MTB. The composition of MTB was variable, with a dedicated oncologist in 83% of centers, although all cases discussed required the presence of the oncologist. 83% of centers met the ACC criteria for eligibility at MTB discussion. In 83% of cases both the primary and the metastases were analyzed, while in 17% only the metastasis were analyzed. The type of analysis available were target panel sequencing and whole exome sequencing (WES) in 100% of centers, whole genome sequencing (WGS) in 83%, RNA sequencing in 53%. Bioinformatics analysis software used were Illumina pipeline in 50% of centers; Ion Reporter (Thermo Fisher Scientific), QIAGEN CLC Genomics Variant Reporter and Archer Analysis in 33%, 17% and 33% of centers respectively. The knowledge base software for variant interpretation in precision oncology were Oncomine Reporter and Sophia, both in 17%. Other specific tools (e.g., CibersortX, GATK suite, and DEseq2) were used in 33% of centers. The time required for the analysis was ≤ 10 days in 33% of centers and > 10 days in 67%. In 83% of centers results are stored locally, and a database with clinical data and follow-up was recorded.ConclusionMTBs were present in most sarcoma referral centers that answered the survey, albeit with different organizational arrangements. Although this survey should be regarded merely as a descriptive analysis of the early stages of MTB use in sarcomas, and is not representative of the national landscape as a whole, it highlights the clinical need to develop expertise in using MTB for rare cancers and to standardize the process and may serve as a basis for future larger-scale, prospective efforts aimed at harmonizing MTB practices across Italian sarcoma centers.

Objective:Dinutuximab beta (dB) immunotherapy is used as maintenance treatment for relapsed/refractory neuroblastoma (NBL); however, comparative studies directly comparing dB with no dB therapy in this setting are lacking. This study aimed to indirectly compare dB (with or without interleukin-2) with no immunotherapy in patients with relapsed NBL. Methods:Three studies of dB (APN311-202, APN311-304, and APN311-303) with individual patient data, along with two historical control cohorts (INBR and R1) were included. Both unadjusted (naïve) and population-adjusted comparisons of overall survival (OS) were performed, with adjustment conducted using inverse probability or odds weighting. Harmonized inclusion criteria were applied across all study populations. The adjusted comparison used the propensity score reweighting to balance the cohorts based on key baseline prognostic factors. Results:The base-case unadjusted indirect comparison revealed that dB (with or without IL-2) significantly prolonged OS compared to historical controls not treated with dB (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.31- 0.79; p<0.001). Similarly, in the adjusted comparison, dB significantly prolonged OS compared to historical controls (HR, 0.53; 95% CI, 0.35; 0.79, p=0.002). All sensitivity unadjusted and adjusted comparisons supported the results of the base-case analysis. Conclusion:Dinutuximab beta significantly prolonged OS compared to historical control cohorts not treated with dB in both unadjusted and adjusted indirect comparisons.