Osteosarcoma is the most common malignant bone tumor, primarily affecting adolescents and young adults. Patients with metastases have a low survival rate, making the identification of prognostic markers crucial. The adaptor protein CIN85 is involved in various signaling pathways that regulate cell differentiation, adhesion, and motility. Its overexpression is associated with poor prognosis in multiple cancers. However, the role of CIN85 in osteosarcoma progression has not yet been explored. This study shows that CIN85 expression is higher in osteosarcoma than in normal bone tissue and further increased in metastatic lesions relative to primary tumors. CIN85 overexpression increases cell migration and Matrigel invasion, whereas silencing CIN85 suppresses these behaviors. Functional annotation and enrichment analyses of the CIN85‐driven transcriptome suggest that CIN85 regulates migration, adhesion, and extracellular matrix organization in osteosarcoma. CIN85 affects MMP2 and COL3A1 gene expression and activates Akt/mTOR signaling. Knockdown of MMP2 and COL3A1 or pharmacological inhibion of Akt/mTOR signaling abrogates CIN85‐induced motility. This study demonstrates that elevated CIN85 expression contributes to osteosarcoma migration and metastasis, highlighting its potential as a therapeutic target.

Background: Giant cell tumor of bone (GCTB) is a locally aggressive tumor characterized by osteoclast-like giant cells and neoplastic stromal cells. While denosumab effectively targets giant cells, stromal cells may persist and drive recurrence. This study evaluates the efficacy and safety of a novel neoadjuvant regimen combining denosumab with sunitinib, a tyrosine kinase inhibitor targeting stromal cell signaling. To our knowledge, this represents the first clinical series evaluating a novel neoadjuvant regimen combining denosumab with sunitinib in GCTB. Methods: We conducted a retrospective case series of 16 patients with histologically confirmed Campanacci grade 3 (or grade 2 in anatomically challenging locations) GCTB treated at a tertiary sarcoma center between January 2019 and September 2024. All patients received neoadjuvant denosumab and sunitinib prior to definitive surgery. Surgical outcomes, local recurrence, histopathological tumor regression, disease-free survival, and the relative tyrosine phosphorylation levels were analyzed. Results: Of the 16 patients (mean age 28.7 years), most had Campanacci grade 3 lesions (87.5%). En-bloc resection was performed in 43.8% and curettage in 50% of cases. Histological analysis showed near-complete regression of giant cells (mean 99.7%) and partial regression of stromal cells (mean 62.8%). Two patients (12.5%) experienced local recurrence. Disease-free survival at two years was 80%. Treatment was well tolerated, with no unexpected adverse events or dose-limiting toxicities. Conclusion: Neoadjuvant combination therapy with denosumab and sunitinib was feasible and well tolerated and resulted in substantial histological regression of both giant cells and neoplastic stromal cells. While recurrence outcomes in this limited cohort remain descriptive, the observed stromal suppression and RTK signaling profiles support the biological rationale for dual-targeted therapy. These findings justify further prospective investigation, particularly in aggressive or surgically challenging GCTB cases.

INTRODUCTION:We examined the impact of the treatment centre volumes (number of patients per centre) on the management and outcomes of rhabdomyosarcoma (RMS) patients enrolled. METHODS:We analysed 1613 patients with localised RMS treated from 2005 to 2016 in 126 European centres classified as high-, medium-, or low-volume according to the number of patients enrolled in the RMS 2005 protocol coordinated by the European paediatric Soft tissue sarcoma Study Group (EpSSG). We evaluated diagnostic and treatment indicators, protocol adherence and survival outcomes. RESULT:Patients' demographic and tumour characteristics were overall comparable across groups, though high-volume centres treated more patients with advanced disease. Diagnostic work-up largely adhered to protocol recommendations, with minor differences: high-volume centres showed greater adherence to central pathology review (77.7%) and molecular testing (76.2%), while medium-volume centres used 18FDG-PET/CT more frequently (39.7%). Risk group misclassification occurred in 4.5% of patients, more often in low-volume centres. Other treatment quality indicators, including surgical margins, chemotherapy adherence, radiotherapy administration, and participation in the randomised trials, were comparable among groups. Five-year event-free survival and overall survival did not differ significantly between groups, including high-risk subgroups. CONCLUSION:In the treatment of paediatric RMS, adherence to standardised treatment protocols ensures consistent outcomes across centres of varying volumes. Observed differences in specific diagnostic processes highlight the importance of fostering international collaboration and drawing on the expertise of high-volume centres to enhance the quality of care and outcomes for paediatric RMS patients. The adoption of a standardised international protocol would help standardise care and outcomes across Europe, thereby minimising geographical disparities and ensuring equitable access to high-quality treatment.

Background: We present a case of a 12-month-old female patient with metastatic neuroblastoma who was transferred to our institution after disease progression following two cycles of standard treatment in Ukraine. Upon admission, the child was critically ill, presenting with a large abdominal mass, severe cachexia, deep vein thrombosis with limb oedema, and oxygen dependency due to limited chest excursions. Case report: After initial stabilization, comprehensive genomic profiling revealed an SRGAP3:NTRK2 gene fusion in the tumor sample. An individualized combination of standard chemotherapy, targeted treatment with larotrectinib, and metronomic chemotherapy was administered. This regimen resulted in a radiologically confirmed partial response and a notable clinical improvement. Conclusion: This case documents a rare instance of NTRK2 fusion-driven neuroblastoma successfully treated with a regimen containing a pan-TRK inhibitor that proved to be well-tolerated and effective.

We have recently identified transcription factor c-Myb as a negative prognostic factor in osteosarcoma (OSA) patients associated with metastatic disease. Transcriptomic analysis identified creatine kinase B (CKB) as one of the most deregulated genes in OSA cell lines with depleted MYB. CKB is a component of the creatine/phosphocreatine system that plays a key role in maintaining cellular energy homeostasis and energy transport to sites with high demand. This study was therefore conducted to investigate the functional significance of CKB in OSA. Deregulation of CKB by c-Myb in OSA cells was analyzed using gain-of-function/loss-of-function approach. Transactivation of the CKB promoter by c-Myb was assessed using a reporter assay. CRISPR/Cas9, RNAi and cyclocreatine were used to inhibit the expression/activity of CKB in OSA cells. Cell growth, colony-forming capacity, cell migration, chemosensitivity in vitro and metastatic capacity in vivo was examined. CKB protein effectors were identified using liquid chromatography-mass spectrometry (LC-MS) in data-independent acquisition-parallel accumulation serial fragmentation mode. CKB was validated as c-Myb target in OSA cell lines. Depletion of CKB using CRISPR/Cas9 resulted in slower migration of OSA cells in vitro and reduced metastatic capacity in immunodeficient mice. siRNA and cyclocreatine inhibited OSA cell migration as well but in this case, cell proliferation was also reduced. A total of 8474 protein groups were quantified, with 147 downregulated and 143 upregulated protein groups associated with the CKB knockout phenotype. The deregulated proteins were enriched for those associated with cell migration and motility. N-cadherin, an established regulator of cell migration, was identified as a target of CKB signaling and its role in OSA cell migration and metastasis was confirmed. c-Myb – CKB – N-cadherin axis was identified as pathway regulating OSA cell migration and metastasis.

Hand and foot osteosarcoma represents similar to 1% of all diagnosed cases of osteosarcoma. The rarity of osteosarcoma of the hand and foot leads to frequent misdiagnosis, delayed diagnosis or incorrect treatments, which can lead to fatal consequences. Typically, salvaging the affected limb is the treatment of choice, and with the use of chemotherapy, 60-65% of patients with osteosarcoma can be treated without amputation. Due to its rarity, misdiagnosis and treatment delays are common, yet detailed reviews and analyses of such cases are limited. The present retrospective cohort study aimed to review and analyze cases of osteosarcoma located in the hand and foot. From January 2007 to January 2019, 11 patients were treated at the Masaryk Memorial Cancer Institute Sarcoma Center (Brno, Czechia), 5 cases affected the hand and 6 affected the foot. A total of 6 male patients and 5 female patients, with a mean age of 30.9 +/- 16.74 years, were diagnosed with hand or foot osteosarcoma. The mean follow-up period was 90.36 +/- 66.14 months. The mean tumor size detected during diagnosis was 4.29 +/- 1.81 cm. Osteoblastic osteosarcoma was the most common histopathological type, accounting for 4 cases (33.4%). A majority of the osteosarcomas were identified as high grade (81.8%). A total of 5 patients experienced misdiagnoses following their initial biopsy, with 2 patients initially receiving treatment outside the Masaryk Memorial Cancer Institute Sarcoma Center. The most frequently encountered misdiagnosis was giant-cell tumor of the bone. A total of 3 patients underwent limb amputation and 2 patients developed lung metastasis and succumbed to the disease. The disease-free survival period and overall survival rate were calculated using Kaplan-Meier survival analysis. The mean disease-free survival period was 82.83 +/- 60.05 months, while the overall survival rate was 72%, with a mean survival time of 90.36 +/- 56.73 months. In summary, an examination of a case series involving 11 patients diagnosed with osteosarcoma of the hand and foot was conducted. The treatment approach, clinical characteristics and patient outcomes were described. A total of four case studies of patients with osteosarcoma in the hand or foot were presented. Misdiagnosis of this disease may result in the inappropriate treatment being administered to patients, therefore, the correct and rapid diagnosis of disease is necessary for effective treatment of hand and foot osteosarcomas.

Constitutional mismatch repair deficiency (CMMRD) is a rare syndrome characterized by an increased incidence of cancer. It is caused by biallelic germline mutations in one of the four mismatch repair genes (MMR) genes: MLH1, MSH2, MSH6, or PMS2. Accurate diagnosis accompanied by a proper molecular genetic examination plays a crucial role in cancer management and also has implications for other family members. In this report, we share the impact of the diagnosis and challenges during the clinical management of two brothers with CMMRD from a non-consanguineous family harbouring compound heterozygous variants in the PMS2 gene. Both brothers presented with different phenotypic manifestations and cancer spectrum. Treatment involving immune checkpoint inhibitors significantly contributed to prolonged survival in both patients affected by lethal gliomas. The uniform hypermutation also allowed immune-directed treatment using nivolumab for the B-cell lymphoma, thereby limiting the intensive chemotherapy exposure in this young patient who remains at risk for subsequent malignancies.

Despite significant improvement in the survival of pediatric patients with cancer, treatment outcomes for high-risk, relapsed, and refractory cancers remain unsatisfactory. Moreover, prolonged survival is frequently associated with long-term adverse effects due to intensive multimodal treatments. Accelerating the progress of pediatric oncology requires both therapeutic advances and strategies to mitigate the long-term cytotoxic side effects, potentially through targeting specific molecular drivers of pediatric malignancies. In this report, we present the results of integrative genomic and transcriptomic profiling of 230 patients with malignant solid tumors (the "primary cohort") and 18 patients with recurrent or otherwise difficult-to-treat nonmalignant conditions (the "secondary cohort"). The integrative workflow for the primary cohort enabled the identification of clinically significant single nucleotide variants, small insertions/deletions, and fusion genes, which were found in 55% and 28% of patients, respectively. For 38% of patients, molecularly informed treatment recommendations were made. In the secondary cohort, known or potentially driving alteration was detected in 89% of cases, including a suspected novel causal gene for patients with inclusion body infantile digital fibromatosis. Furthermore, 47% of findings also brought therapeutic implications for subsequent management. Across both cohorts, changes or refinements to the original histopathological diagnoses were achieved in 4% of cases. Our study demonstrates the efficacy of integrating advanced genomic and transcriptomic analyses to identify therapeutic targets, refine diagnoses, and optimize treatment strategies for challenging pediatric and young adult malignancies and underscores the need for broad implementation of precision oncology in clinical settings.

Background: The authors report the prospective evaluation of reduced dose alkylator chemotherapy combined with radiotherapy for European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) standard risk nonalveolar rhabdomyosarcoma (NA-RMS). Patients and Methods: Localized node negative Intergroup Rhabdomyosarcoma Study (IRS) II/III NA-RMS at favorable sites (subgroup C), <25 years old, received five cycles of ifosfamide, vincristine, and dactinomycin (IVA) chemotherapy (30 g/m(2) ifosfamide) and four cycles of vincristine and dactinomycin (if receiving radiotherapy), or nine cycles of IVA (54 g/m(2) ifosfamide) +/- radiotherapy. Delayed primary tumor excision was considered for IRS III tumors. The primary end points were event-free survival (EFS) and overall survival (OS). Results: From October 2005 to December 2016, 359 evaluable patients were recruited: orbit, 164 (45.7%); head and neck nonparameningeal, 77 (21.4%); and genitourinary non-bladder/prostate, 118 (32.9%). EFS and OS were 77.4% (95% confidence interval [CI], 72.5-81.6) and 93.5% (95% CI, 90.1-95.8), respectively. Lower dose alkylator chemotherapy and radiotherapy achieved 5-year OS of 93.7% but the difference with higher dose alkylator chemotherapy +/- radiotherapy was not significant (p = 0.8003). Adjuvant radiotherapy improved EFS with 5-year estimates of 84.7% versus 65.2% for nonirradiated (p < .0001), but not OS (p = .9298). Omitting radiotherapy for orbital tumors reduced OS (5-year was 87.1% vs. 97.3% for irradiated, p = .0257). Following R0 resection (n = 60), radiotherapy did not significantly improve EFS or OS. Conclusions: Radiotherapy for local tumor control allows for reduction of cumulative dose of alkylators in EpSSG standard risk subgroup C RMS patients. The omission of radiotherapy did not affect OS in all patients except those with orbital RMS and was associated with inferior EFS.

A lot of hope for high-risk cancers is being pinned on immunotherapy but the evidence in children is lacking due to the rarity and limited efficacy of single-agent approaches. Here, we aim to assess the effectiveness of multimodal therapy comprising a personalized dendritic cell (DC) vaccine in children with relapsed and/or high-risk solid tumors using the N-of-1 approach in real-world scenario. A total of 160 evaluable events occurred in 48 patients during the 4-year follow-up. Overall survival of the cohort was 7.03 years. Disease control after vaccination was achieved in 53.8% patients. Comparative survival analysis showed the beneficial effect of DC vaccine beyond 2 years from initial diagnosis (HR = 0.53, P = .048) or in patients with disease control (HR = 0.16, P = .00053). A trend for synergistic effect with metronomic cyclophosphamide and/or vinblastine was indicated (HR = 0.60 P = .225). A strong synergistic effect was found for immune check-point inhibitors (ICIs) after priming with the DC vaccine (HR = 0.40, P = .0047). In conclusion, the personalized DC vaccine was an effective component in the multimodal individualized treatment. Personalized DC vaccine was effective in less burdened or more indolent diseases with a favorable safety profile and synergized with metronomic and/or immunomodulating agents.

PURPOSE:Pediatric sarcomas are bone and soft tissue tumors that often exhibit high metastatic potential and refractory stem-like phenotypes, resulting in poor outcomes. Aggressive sarcomas frequently harbor a disrupted p53 pathway. However, whether pediatric sarcoma stemness is associated with abrogated p53 function and might be attenuated via p53 reactivation remains unclear. METHODS:We utilized a unique panel of pediatric sarcoma models and tumor tissue cohorts to investigate the correlation between the expression of stemness-related transcription factors, p53 pathway dysregulations, tumorigenicity in vivo, and clinicopathological features. TP53 mutation status was assessed by next-generation sequencing. Major findings were validated via shRNA-mediated silencing and functional assays. The p53 pathway-targeting drugs were used to explore the effects and selectivity of p53 reactivation against sarcoma cells with stem-like traits. RESULTS:We found that highly tumorigenic stem-like sarcoma cells exhibit dysregulated p53, making them vulnerable to drugs that restore wild-type p53 activity. Immunohistochemistry of mouse xenografts and human tumor tissues revealed that p53 dysregulations, together with enhanced expression of the stemness-related transcription factors SOX2 or KLF4, are crucial features in pediatric osteosarcoma, rhabdomyosarcoma, and Ewing's sarcoma development. p53 dysregulation appears to be an important step for sarcoma cells to acquire a fully stem-like phenotype, and p53-positive pediatric sarcomas exhibit a high frequency of early metastasis. Importantly, reactivating p53 signaling via MDM2/MDMX inhibition selectively induces apoptosis in aggressive, stem-like Ewing's sarcoma cells while sparing healthy fibroblasts. CONCLUSIONS:Our results indicate that restoring canonical p53 activity provides a promising strategy for developing improved therapies for pediatric sarcomas with unfavorable stem-like traits.

OBJECTIVES The objective of this study was to determine the incidence of neoplastic diseases and associated risk factors in the early stages of life. METHODS Data were retrospectively assessed in 730,000 live births between 2000 and 2019. The occurrence of tumors was monitored in the neonatal, infant (1-12 months), and toddler (13-24 months) periods. Risk factors were divided into demographic, internal, and environmental factors. The control group consisted of subjects in the same age category without oncological diseases. RESULTS A total of 452 neoplastic diseases were diagnosed in the study sample. In total, 24% (110/452) manifested during the neonatal period, 45% (203/452) in infants, and 31% (139/452) at the age of 13-24 months. Any genetic disease (OR 26.68; 95% CI 7.64-93.12) and medications used by the mother (OR 3.07; 95% CI 1.32-7.15) were identified as risk factors. Without adjustment for all factors, asphyxia in the first minute, a younger age of the mother, lower pregnancy, and the presence of a congenital defect manifested themselves as risk factors. CONCLUSIONS The highest risk factors for the development of early childhood tumors were identified as with medications used by the mother before or during pregnancy and genetic diseases.

Background: Despite major improvements in the survival of pediatric cancer patients that were achieved through the intensification of chemotherapy and the perfection of supportive care in the past decades, treatment outcomes for high-risk, relapsed, and refractory solid cancers remain unsatisfactory. Accelerating the progress of pediatric oncology requires both therapeutic advances and attention to reducing the long-term cytotoxic treatment-related side effects. This could be achieved by targeting specific molecular changes that drive pediatric malignancies. Material and Methods: From September 2016 to August 2020, a total of 192 patients with pediatric high-risk solid tumors successfully underwent comprehensive genomic profiling. Since more than thirty patients had two or more biopsies from recurrent relapses, the total number of samples examined was 295. In the cohort, there were 78 cases of central nervous system tumors, 68 sarcomas, 14 neuroblastomas, 10 lymphomas, and 22 tumors of other histology. Whole-exome sequencing was performed in all patients, fusion gene analysis in 96% of patients, whole-transcriptome profiling in 84% of patients, and CNV analysis in 63% of patients. Results: The diagnostic yield of therapeutically actionable findings was 40%, with single-nucleotide variants and small insertions/deletions being the most common actionable alteration types. In 23% of patients, a clinically relevant gene fusion was identified. The majority of the identified fusions were of diagnostic significance, and 18% of those were therapeutically targetable gene fusions involving BRAF, RAF1, ALK, FGFR1, or NTRK2. Four patients were eligible for immunotherapy based on high tumor mutational burden (>10 mut/Mb). Lymphomas and CNS tumors showed the highest rate of patients with therapeutically actionable findings (60% and 56%, respectively), followed by neuroblastomas (36%), sarcomas (25%), and other solid tumors (23%). All results and individual treatment plans were discussed at multidisciplinary molecular tumor boards. Conclusion: Precision medicine in pediatric oncology has rapidly developed over the last decade and resulted in new therapeutic options based on molecular biomarkers and increased our understanding of the complexity of pediatric malignancies. Supported by the Ministry of Health of the Czech Republic, grant nr. NU20-03-00240 and the project National Institute for Cancer Research (Programme EXCELES, ID Project No. LX22NPO5102) - Funded by the European Union - Next Generation EU. Citation Format: Petra Pokorna, Hana Palova, Sona Adamcova, Vojtech Bystry, Michal Kyr, Dagmar Al Tukmachi, Sona Mejstrikova, Peter Mudry, Jaroslav Sterba, Ondrej Slaby. Impact of the comprehensive genomic profiling on the individual therapeutic planning in high-risk/refractory tumors: real-world precision medicine in pediatric oncology. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4511.

10035 Background: Despite major improvements in the survival of pediatric cancer patients that were achieved through the intensification of chemotherapy and the perfection of supportive care in the past decades, treatment outcomes for high-risk, relapsed, and refractory solid cancers remain unsatisfactory. Accelerating the progress of pediatric oncology requires both therapeutic advances and attention to reducing the long-term cytotoxic treatment-related side effects. This could be achieved by targeting specific molecular changes that drive pediatric malignancies. Methods: From September 2016 to August 2020, a total of 192 patients with pediatric high-risk solid tumors successfully underwent comprehensive genomic profiling. Since more than thirty patients had two or more biopsies from recurrent relapses, the total number of samples examined was 295. In the cohort, there were 78 cases of central nervous system tumors, 68 sarcomas, 14 neuroblastomas, 10 lymphomas, and 22 tumors of other histology. Whole-exome sequencing was performed in all patients, fusion gene analysis in 96% of patients, whole-transcriptome profiling in 84% of patients, and CNV analysis in 63% of patients. Results: The diagnostic yield of therapeutically actionable findings was 40%, with single-nucleotide variants and small insertions/deletions being the most common actionable alteration types. In 23% of patients, a clinically relevant gene fusion was identified. The majority of the identified fusions were of diagnostic significance, and 18% of those were therapeutically targetable gene fusions involving BRAF, RAF1, ALK, FGFR1, or NTRK2. Four patients were eligible for immunotherapy based on high tumor mutational burden ( > 10 mut/Mb). Lymphomas and CNS tumors showed the highest rate of patients with therapeutically actionable findings (60% and 56%, respectively), followed by neuroblastomas (36%), sarcomas (25%), and other solid tumors (23%). All results and individual treatment plans were discussed and approved at multidisciplinary molecular tumor boards. Conclusions: Precision medicine in pediatric oncology has rapidly developed over the last decade and resulted in new therapeutic options based on molecular biomarkers and increased our understanding of the complexity of pediatric malignancies. Supported by the Ministry of Health of the Czech Republic, grant nr. NU20-03-00240 and the project National Institute for Cancer Research (Programme EXCELES, ID Project No. LX22NPO5102) - Funded by the European Union - Next Generation EU.

This was a prospective cohort study of eighteen patients with large and debilitating vascular malformations with one or more major systemic complications. In all patients, we discovered activating alterations in either TEK or PIK3CA. Based on these findings, targeted treatment using the PI3K inhibitor alpelisib was started with regular check-ups, therapy duration varied from 6 to 31 months. In all patients, marked improvement in quality of life was observed. We observed radiological improvement in fourteen patients (two of them being on combination with either propranolol or sirolimus), stable disease in 2 patients. For 2 patients, an MRI scan was not available as they were shortly on treatment, however, a clinically visible response in size reduction or structure regression, together with pain relief was observed. In patients with elevated D-dimer levels before alpelisib administration, a major improvement was noted, suggesting its biomarker role. We observed overall very good tolerance of the treatment, documenting a single patient with grade 3 hyperglycemia. Patients with size reduction were offered local therapies wherever possible. Our report presents a promising approach for the treatment of VMs harboring different targetable TEK and PIK3CA gene mutations with a low toxicity profile and high efficacy.

Vascular anomalies are a heterogeneous group of rare diseases caused by defects in the early stages of vascular development that result in abnormal growth and development of vessels. The treatment typically consists of surgical approaches; unfortunately, many anomalies cannot be cured. Therefore, the goal of the treatment is to control the lesion, and progression or recurrence after an intervention is no exception. In the last 15 years, tremendous progress in understanding the molecular basis of the disease has been made, with alterations in more than 40 genes proven to be causal in the disease pathogenesis. Interestingly, such alterations are also found in many human cancers, which recently raised the question of whether repurposing anti-cancer drugs could be utilized in this setting. Tissue biopsies from 38 patients with vascular anomalies have been analyzed using different approaches ranging from Sanger sequencing to NGS-based detection. In 31 patients, known causal alterations of either germline or somatic origin were found. For the remaining seven patients, sampling issues were considered a cause of the negative result. Given that most patients suffered from a venous type of malformation, most alterations were found in TEK and PIK3CA genes, which are commonly altered in this subgroup. Other findings included alterations of KRAS, GLMN, PTEN, or IDH2 genes. TEK gene mutations were predominantly located in exon 17, which encodes for a part of the tyrosine kinase domain of the protein, with frequent L914F substitution being found in 12 cases. Identified PIK3CA gene mutations were all well-characterized activating alterations described in cancer-related context. Based on an identification of either TEK or PIK3CA mutation, 13 patients were administered targeted treatment using selective PI3K alpha subunit inhibitor alpelisib. For all patients, improvement in quality of life, lesion reduction and normalization of coagulation parameters was achieved. A deeper understanding of the pathophysiology of vascular anomalies can significantly contribute to patient stratification, identification of potential therapeutic targets, and overall better clinical management. At the same time, identifying potential therapeutic targets could lead to the administration of novel anti-cancer drugs within the concept of drug repurposing and better overall disease control compared to routinely used approaches. Supported by the Ministry of Health of the Czech Republic, grant nr. NU20-03-00240 and by the project National Institute for Cancer Research (Programme EXCELES, ID Project No. LX22NPO5102) - Funded by the European Union - Next Generation EU. Citation Format: Petra Pokorna, Renata Faberova, Olga Koskova, Martin Sterba, Hana Palova, Katerina Kozelkova, Robin Jugas, Dagmar Al Tukmachi, Tana Machackova, Jiri Sana, Peter Mudry, Jaroslav Sterba, Ondrej Slaby. Precision medicine and cancer drug repurposing in the management of vascular anomalies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1063.

Giant cell tumour of bone (GCTB) is one of the most common local aggressive tumourous lesions with a wide variety of biological behaviour. However, there are no clear indicative criteria when choosing the type of procedure and the complication rates remain high, especially in terms of local recurrence. The purpose of the study was to (1) identify the main risk factors for local recurrence, (2) evaluate the recurrence-free survival in dependence on neoadjuvant denosumab use and the type of procedure, and (3) compare the functional outcomes after curettage and en bloc resection. The group included 102 patients with GCTB treated between 2006 and 2020. The mean age of patients was 34.4 years (15-79). The follow-up period was 8.32 years (2-16) on average. Local recurrence occurred in 14 patients (29.8%) who underwent curettage and in 5 patients (10.6%) after en bloc resection. Curettage was shown to be a factor in increasing recurrence rates (OR = 3.64 [95% CI: 1.19-11.15]; p = 0.023). Tibial location was an independent risk factor for local recurrence regardless of the type of surgery (OR = 3.22 [95% CI: 1.09-9.48]; p = 0.026). The recurrence-free survival rate of patients treated with resection and denosumab was higher compared to other treatments at five years postoperatively (p = 0.0307). Functional ability and pain as reported by patients at the latest follow-up were superior after curettage compared to resection for upper and lower extremity (mean difference: -4.00 [95% CI: -6.81 to -1.18]; p < 0.001 and mean difference: -5.36 [95% CI: -3.74 to -6.97]; p < 0.001, respectively). Proximal tibia tumour location and curettage were shown to be major risk factors for local recurrence in GCTB regardless of neoadjuvant denosumab treatment. The recurrence-free survival rate of patients treated with resection and denosumab was higher compared to other treatments. The functional outcome of patients after curettage was better compared to en bloc resection.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. The RMS2005 study included two phase III randomized trials for high-risk (HR) and observational trials for low (LR), standard (SR), and very high-risk (VHR) patients who have been partially reported. Herein, we present a comprehensive report of results achieved for the complete unselected nonmetastatic cohort and analyze the evolution of treatment in comparison with previous European protocols. After a median follow-up of 73.1 months, the 5-year event-free survival (EFS) and overall survival (OS) of the 1,733 patients enrolled were 70.7% (95% CI, 68.5 to 72.8) and 80.4% (95% CI, 78.4 to 82.3), respectively. The results by subgroup: LR (80 patients) EFS 93.7% (95% CI, 85.5 to 97.3), OS 96.7% (95% CI, 87.2 to 99.2); SR (652 patients) EFS 77.4% (95% CI, 73.9 to 80.5), OS 90.6% (95% CI, 87.9 to 92.7); HR (851 patients) EFS 67.3% (95% CI, 64.0 to 70.4), OS 76.7% (95% CI, 73.6 to 79.4); and VHR (150 patients) EFS 48.8% (95% CI, 40.4 to 56.7), OS 49.7% (95% CI, 40.8 to 57.9). The RMS2005 study demonstrated that 80% of children with localized rhabdomyosarcoma could be long-term survivors. The study has established the standard of care across the European pediatric Soft tissue sarcoma Study Group countries with the confirmation of a 22-week vincristine/actinomycin D regimen for LR patients, the reduction of the cumulative ifosfamide dose in the SR group, and for HR disease, the omission of doxorubicin and the addition of maintenance chemotherapy.