Joint-Sparing Resection around the Knee for Osteosarcoma: Long-Term Outcomes of Biologic Reconstruction with Vascularized Fibula Graft Combined with Massive Allograft.

(1) Background: We aim to address the following questions. What was the complication rate of vascularized fibula graft (VFG) combined with massive allograft in patients treated with joint-sparing resection around the knee for a high-grade osteosarcoma? What was the long-term survivorship of VFG free from revision and graft removal? What were the functional results as assessed by the Musculoskeletal Tumor Society (MSTS) score? (2) Methods: 39 patients treated in our unit for osteosarcoma around the knee with intercalary resection and reconstruction with VFG combined with massive allograft were included; 26 patients underwent intercalary tibial resection, while 13 underwent intercalary femoral resection. (3) Results: Mean Follow-Up was 205 months (28 to 424). Complications that required surgery were assessed in requiring surgical revision in 19 patients (49%) after a mean of 31 months (0 to 107), while VFG removal was necessary in three patients (8%). The revision-free survival of the reconstructions was 59% at 5 years and 50% at 10 to 30 years. The overall survival of the reconstructions was 95% at 5 to 15 years and 89% at 20 to 30 years. The mean MSTS score was 29.3 (23 to 30). (4) Conclusions: VFG represents an effective reconstructive option after joint-sparing intercalary resection around the knee for osteosarcoma.

Blockade of IL-10 Signaling Ensures Mifamurtide Efficacy in Metastatic Osteosarcoma.

Osteosarcoma (OS) is the most common primary malignancy of the bone, highly aggressive and metastasizing, and it mainly affects children and adolescents. The current standard of care for OS is a combination of surgery and chemotherapy. However, these treatment options are not always successful, especially in cases of metastatic or recurrent osteosarcomas. For this reason, research into new therapeutic strategies is currently underway, and immunotherapies have received considerable attention. Mifamurtide stands out among the most studied immunostimulant drugs; nevertheless, there are very conflicting opinions on its therapeutic efficacy. Here, we aimed to investigate mifamurtide efficacy through in vitro and in vivo experiments. Our results led us to identify a new possible target useful to improve mifamurtide effectiveness on metastatic OS: the cytokine interleukin-10 (IL-10). We provide experimental evidence that the synergic use of an anti-IL-10 antibody in combination with mifamurtide causes a significantly increased mortality rate in highest-grade OS cells and lower metastasis in an in vivo model compared with mifamurtide alone. Overall, our data suggest that mifamurtide in combination with an anti-IL-10 antibody could be proposed as a new treatment protocol to be studied to improve the outcomes of OS patients.

Cardio-Oncology in Childhood: State of the Art.

PURPOSE OF REVIEW: Cardio-oncology is an increasingly important field of cardiology that focuses on the detection, monitoring, and treatment of cardiovascular disease (CVD) occurring during and after oncological treatments. The survival rate for childhood cancer patients has dramatically increased thanks to new treatment protocols and cardiovascular (CV) sequelae represent the third most frequent cause of mortality in surviving patients. This study aims to provide a complete and updated review of all the main aspects of cardio-oncology in childhood and to highlight the critical issues. RECENT FINDINGS: The problem of CV complications in childhood cancer survivors raises the need to make an early diagnosis of cardiotoxicity by the new imaging and laboratory techniques in order to intervene promptly and to implement pharmacological strategies and lifestyle changes to reduce or even to prevent cardiac injury. Furthermore, a stratification of CV risk, also including new predisposing factors such as the presence of some genetic mutations, is of paramount importance before undertaking oncological treatments. Besides, a systematic and personalized planning of long-term follow-up is fundamental to ensure a transition from pediatric to adult hospital and to avoid missed or late diagnosis of cardiomyopathy. We reviewed the main risk factors for cardiotoxicity in children, both traditional and emerging ones: the mechanisms of toxicity of both old and new antineoplastic therapies, the techniques for detecting cardiac damage, and the current evidence regarding pharmacological cardioprotection. At the end, we focused our attention on the existing guidelines and strategies about the long-term follow-up of childhood cancer survivors.

A Unique Case of Primary Cutaneous Adenoid Cystic Carcinoma Associated with Aplasia Cutis Congenita in a Four-Year-Old Female: A Case Report.

INTRODUCTION: Primary cutaneous adenoid-cystic carcinoma (PCACC) is a rare malignant tumour reported in only about 450 cases in the literature, with only two adolescent cases reported. PCACC seems to occur between the fifth and seventh decade of life, and the most frequent regions involved are head and neck (46%). Aplasia cutis congenita (ACC) has an incidence of 1:10,000, and it seems to be rarely associated with neoplastic lesions. Interestingly, the association between PCACC and ACC has, so far, never been described. METHODS: We report a case of PCACC in the scalp associated with ACC in a four-year-old patient. DISCUSSION: The patient was under follow-up at the dermatology unit, but suddenly a red lesion appeared within the ACC. This red, ulcerated area increased rapidly over six months, so it was surgically removed, and the pathological examination results were suggestive for cribriform PCACC. According to the guidelines for skin tumours, the patient underwent widening resection, and an advancement-sliding skin flap was performed to recreate the scalp. After one year of follow-up, the patient has no local or widespread recurrence of the PCACC, and the surgical scar appears to have healed well. CONCLUSIONS: This clinical case is the first known patient with PCACC associated with ACC. A skin excision biopsy should be performed with wide margins to avoid a second widening resection of skin in a similar scenario. Genetic studies may help to identify the origin of this rare association.

Phase 2 study for nonmetastatic extremity high-grade osteosarcoma in pediatric and adolescent and young adult patients with a risk-adapted strategy based on ABCB1/P-glycoprotein expression: An Italian Sarcoma Group trial (ISG/OS-2).

BACKGROUND: According to retrospective osteosarcoma series, ABCB1/P-glycoprotein (Pgp) overexpression predicts for poor outcomes. A prospective trial to assess a risk-adapted treatment strategy using mifamurtide in Pgp+ patients was performed. METHODS: This was a phase 2, multicenter, uncontrolled trial including patients 40 years old or younger with nonmetastatic extremity high-grade osteosarcoma stratified according to Pgp expression. All patients received high-dose methotrexate, doxorubicin, and cisplatin (MAP) preoperatively. In Pgp+ patients, mifamurtide was added postoperatively and combined with MAP for a good histologic response (necrosis ≥ 90%; good responders [GRs]) or with high-dose ifosfamide (HDIFO) at 3 g/m2 /d on days 1 to 5 for a histologic response < 90% (poor responders [PRs]). Pgp- patients received MAP postoperatively. After an amendment, the cumulative dose of methotrexate was increased from 60 to 120 g/m2 (from 5 to 10 courses). The primary end point was event-free survival (EFS). A postamendment analysis was performed. RESULTS: In all, 279 patients were recruited, and 194 were included in the postamendment analysis: 70 (36%) were Pgp-, and 124 (64%) were Pgp+. The median follow-up was 51 months. For Pgp+ patients, 5-year EFS after definitive surgery (null hypothesis, 40%) was 69.8% (90% confidence interval [CI], 62.2%-76.2%): 59.8% in PRs and 83.7% in GRs. For Pgp- patients, the 5-year EFS rate was 66.4% (90% CI, 55.6%-75.1%). CONCLUSIONS: This study showed that adjuvant mifamurtide, combined with HDIFO for a poor response to induction chemotherapy, could improve EFS in Pgp+ patients. Overall, the outcomes compared favorably with previous series. Mifamurtide and HDIFO as salvage chemotherapy are worth further study.

Role of centers with different patient volumes in the management of rhabdomyosarcoma. An analysis by the Italian Pediatric Soft Tissue Sarcoma Committee.

PROCEDURE: The survival of children with rhabdomyosarcoma (RMS) has gradually improved as a result of the adoption of multidisciplinary treatments. Dedicated skills and facilities are indispensable and more readily available at reference centers. In this study, we examined the role of centers' experience (based on the number of patients treated) in their management of patients with RMS. METHODS: We analyzed 342 patients with localized RMS enrolled in the European RMS 2005 protocol from October 2005 to December 2016 at 31 Italian centers that are part of the Soft Tissue Sarcoma Committee (STSC). We grouped the centers by the number of patients each one enrolled (Group 1: >40; Group 2: <40 and >10; and Group 3: <10), and compared a number of indicators to assess the appropriateness of patients' diagnostic workup and treatment and their survival. RESULTS: Overall, 74.6% of patients were treated at 10 centers, and only three of them classifiable as high-volume centers. Only minor differences emerged between the three patient groups in terms of diagnostic investigations and treatment modalities. Survival was similar in the three groups. Approximately, one in four children treated at the centers in Groups 2 and 3 traveled to another center for surgery or radiotherapy. CONCLUSION: Patients treated at STSC centers with different amounts of experience had similar results in terms of survival. This is attributable to all centers in the network adhering to protocol recommendations and receiving the STSC's support on diagnostics and multidisciplinary treatments for RMS.

Front-Line Window Therapy with Temozolomide and Irinotecan in Patients with Primary Disseminated Multifocal Ewing Sarcoma: Results of the ISG/AIEOP EW-2 Study.

PURPOSE: The main objective was to evaluate the activity and tolerability of TEMIRI as a front-line treatment in primary disseminated Ewing sarcoma (PDMES) using the RECIST 1.1 criteria. The secondary objectives included the assessment of toxicity and the performance status/symptom changes. METHODS: Between 2012 and 2018, patients with PDMES received two courses of temozolomide 100 mg/sqm/day + irinotecan 50 mg/sqm/day for 5 days every 3 weeks as an amendment to the Italian Sarcoma Group/Associazione Italiana EmatoIogia ed Oncologia Pediatrica (ISG/AIEOP) EW-2 protocol (EUDRACT#2009-012353-37, Vers. 1.02). RESULTS: Thirty-four patients were enrolled. The median age at diagnosis was 19 years (range 3-55). After TEMIRI, the RECIST response was as follows: a partial response in 20 (59%) patients, stable disease in 11 (32%), and disease progression in 3 (9%). The ECOG/Lansky score was improved in 25/34 (73.5%) cases, and a reduction or disappearance of pain was observed in 31/34 patients (91%). The incidence of grade 3-4 toxicity was 3%. The 3-year event-free survival (EFS) and overall survival (OS) were 21% (95% CI 6-35%) and 36% (95% CI: 18-54%), respectively. CONCLUSION: the smooth handling and encouraging activity demonstrated by up-front TEMIRI did not change the EFS in PDMES, so this result suggests the need for the further evaluation of the efficacy of TEMIRI in combination with conventional treatments in non-metastatic patients.

Whole Lung Irradiation after High-Dose Busulfan/Melphalan in Ewing Sarcoma with Lung Metastases: An Italian Sarcoma Group and Associazione Italiana Ematologia Oncologia Pediatrica Joint Study.

PURPOSE: To analyze toxicity and outcome predictors in Ewing sarcoma patients with lung metastases treated with busulfan and melphalan (BU-MEL) followed by whole-lung irradiation (WLI). METHODS: This retrospective study included 68 lung metastatic Ewing Sarcoma patients who underwent WLI after BU-MEL with autologous stem cell transplantation, as part of two prospective and consecutive treatment protocols. WLI 12 Gy for <14 years old and 15 Gy for ≥14 years old patients were applied at least eight weeks after BU-MEL. Toxicity, overall survival (OS), event-free survival (EFS) and pulmonary relapse-free survival (PRFS) were estimated and analyzed. RESULTS: After WLI, grade 1-2 and grade 3 clinical toxicity was reported in 16.2% and 5.9% patients, respectively. The five-year OS, EFS and PRFS with 95% confidence interval (CI) were 69.8% (57.1-79.3), 61.2% (48.4-71.7) and 70.5% (56.3-80.8), respectively. Patients with good histological necrosis of the primary tumor after neoadjuvant chemotherapy showed a significant decreased risk of pulmonary relapse or death compared to patients with poor histological necrosis. CONCLUSIONS: WLI at recommended doses and time interval after BU-MEL is feasible and might contribute to the disease control in Ewing sarcoma with lung metastases and responsive disease. Further studies are needed to explore the treatment stratification based on the histological response of the primary tumor.

Ewing family tumors of the appendicular skeleton: a retrospective analysis of prognostic factors.

PURPOSE: Authors retrospectively analyzed possible prognostic factors in a series of patients affected by Ewing sarcoma of extremities (eEWS) and treated over a 20-year period at a single institution. METHODS: Between 1997 and 2017, 88 bone eEWS were treated at our institution. Staging, age, gender, tumoral volume, local treatment, surgical margins, post-ChT necrosis were investigated for prognostic correlation with overall survival (OS) and event-free survival (EFS). Median follow-up was 74 months (1-236). RESULTS: Staging of disease correlated with OS (81% vs 59%, p = 0.01) and not with EFS (68% vs 57%, p = 0.28) in localized vs metastatic eEWS at presentation. Age ≥ 14 years (p = 0.002) and volume ≥ 100 cm3 (p = 0.04) were significant negative prognostic factors. No difference was found in local treatment: OS was 76% vs 63% (p = 0.33), while EFS was 68% vs 49% (p = 0.06) after surgery alone or surgery + radiotherapy, respectively. Regarding surgical margins, OS was 76% vs 38% (p = 0.14), and EFS was 65% vs 33% (p = 0.14) in adequate vs not adequate, respectively. OS was 86% and 68% in good and poor responders, respectively (p = 0.13). CONCLUSION: In eEWS, metastatic disease at presentation, age > 14 years and tumoral volume > 100 cm3 are negative prognostic factors. Intensified adjuvant ChT can improve prognosis in poor responders and metastatic patients.

Custom-made 3D-printed prosthesis and free vascularised fibula for humeral reconstruction after osteosarcoma resection in a 13-year-old patient.

Surgical reconstruction after humeral resection represents a challenging issue in orthopaedic oncology. Particularly in paediatric patients, the main concerns are maintaining limb function and reconstruction longevity. We describe a novel strategy of humeral reconstruction based on the use of a three-dimensional-printed custom-made prosthesis in a 13-year-old patient diagnosed with osteosarcoma. The implant was specifically designed to sustain the native head, which was spared, as it was not involved by the neoplastic tissue. The mechanical support the prosthesis provided was associated with the biological stimulus of a free vascularised fibular graft to obtain an anatomic, functional and stable construct. This solution has had good longevity, and after 3 years of follow-up, the patient still shows excellent limb function and personal satisfaction.

Custom-Made 3D-Printed Implants as Novel Approach to Reconstructive Surgery after Oncologic Resection in Pediatric Patients.

Recently, custom-made 3D-printed prostheses have been introduced for limb salvage surgery in adult patients, but their use has not been described in pediatric patients. A series of 11 pediatric patients (mean age 10.8 years; range 2-13) with skeletal tumors treated with custom-made implants for the reconstruction of bony defects is described. Patients were followed up every 3 months. Functional results were evaluated by the Musculoskeletal Tumor Society Score (MSTS) for upper and lower limbs. The mean follow-up was 25.7 months (range 14-44). Three patients died after a mean of 19.3 months postoperatively-two because of disease progression and the other from a previous malignancy. Three patients experienced complications related to soft tissues. One patient required device removal, debridement, and antibiotic pearls for postoperative infection. Partial osseointegration between grafts and host bone was observed within a mean of 4 months. At the final follow-up, mean MSTS score was 75%. 3D prostheses may yield biological advantages due to possible integration with the host bone and also through the use of vascularized flaps. Further research is warranted.

Pediatric Malignant Mandibular Tumors: Personal Experience and Literature Options Discussion.

INTRODUCTION: Mandibular defects reconstruction could result challenging in childhood, due to facial and mandibular growth patterns. For these reasons, the choice of the most suitable reconstructive option in pediatric patients, affected by mandibular malignancies, still objects of debate. OBJECTIVE: The aim of our study was to compare our reconstructive schedules to the existing literature in order to give a personal contribute to the present panorama. METHODS: We performed, in October 2019, a retrospective evaluation of pediatric patients treated for biopsy-proven mandibular malignancies at our Institute between January 2013 and December 2016. All of them received multimodal therapy in accordance with standard guidelines and their demographic, clinical, treatment, and outcome parameters were collected and analyzed. RESULTS: We observed a shorter duration of surgery, a faster tracheostomy tube and feeding-tube removal, and a minor hospitalization in patients who received grafts transfer compared to those who underwent microsurgical mandibular reconstruction. After a 36-month period of follow-up, osteochondral grafts showed a pattern of growth similar to the mandibular epiphysis (condilylion-gonion linear and vertical ratio ranging to 0.96-1.03 and 1-1.02 at orthopantomogram, respectively). No bone consolidation delays and functional impairment were recorded. CONCLUSIONS: Free flaps mandibular reconstruction in children needs to be better assessed and proximal fibular epiphyseal free flap indication might deserve further studies. Osteochondral grafts find indication for lateral defects, 50-55 mm in maximum length and located in the mandibular ramus, without massive teeth or soft tissue defect. Condyle involvement does not represent an absolute contraindication to rib graft use.

Analysis of the mutational status of SIX1/2 and microRNA processing genes in paired primary and relapsed Wilms tumors and association with relapse.

Whereas 90% of patients with Wilms tumor (WT) reach cure, approximately half of patients developing a recurrent tumor die of the disease. Therefore, to disclose events leading to recurrence represents a clinical need. To study paired primary/recurrent tumor samples, being aware of the intra-tumoral heterogeneity, might help finding these answers. We previously suggested that mutations in SIX1 and DROSHA underlie WT recurrence. With the aim to better investigate this scenario, we collected 19 paired primary/recurrent tumors and 10 primary tumors from relapsing patients and searched for mutations in the SIX1/2 genes and microRNA processing genes (miRNAPGs). We found SIX1 mutation in one case, miRNAPGs mutations in seven cases, and the co-occurrence of SIX1 and miRNAPG mutations in one case. We could observe that, whereas in primary tumors the mutations could be heterogeneously present, in all cases they were positively selected and homogeneously present in the recurrent disease, as also indicated by a "moderate" and "almost perfect" agreement (according to the Landis and Koch classification criteria) between paired samples. Analysis of SIX1/2 genes and miRNAPGs in 50 non-relapsing WTs disclosed SIX2 mutation in one case and miRNAPGs mutations in seven. A borderline statistically significant association was observed between miRNAPGs mutations and the occurrence of relapse (p value: 0.05). These data suggest that SIX1 and miRNAPGs mutations may provide an advantage during tumor progression to recurrence and can represent oncogenic drivers in WT development.

A hollow, custom-made prosthesis combined with a vascularized flap and bone graft for skeletal reconstruction after bone tumour resection.

PURPOSE: While limb-sparing surgery is now possible for more than 80% of patients with bone tumours, wide resection is often required, necessitating bone reconstruction. This paper aims to present a surgical technique that combines the advantages of a hollow, titanium, custom-made prosthesis and the biological aspects of microsurgical flaps and bone graft. PATIENTS AND METHODS: From June 2016 to September 2017 at our institution, six consecutive patients with skeletal tumours underwent one-stage reconstructive surgery with concomitant implantation of a 3D-printed prosthesis. RESULTS: At an average follow-up of 30 months (range: 18-45), no early complications were observed, and no implant removals were needed. One patient experienced a delayed haematogenous deep infection, which healed after surgical debridement. Three patients died of their underlying disease 18, 22, and 23 months after surgery, respectively. All flaps and custom reconstructions were successful, with primary osseointegration at a mean of four months (range: 2-7). Patients' average Musculoskeletal Tumour Society score was 23.2 (range: 18-28). CONCLUSION: A hollow, custom-made, titanium prosthesis filled with bone graft, used in conjunction with a microsurgical flap, may offer good osseointegration in different anatomic locations among a patient population with a high risk of infection, pseudarthrosis, and long-term mechanical complications. The surgical technique's advantages are preliminarily demonstrated. Further studies with longer follow-up periods and larger sample sizes are required to confirm our findings.

Preliminary Study on ß3-Adrenoreceptor as Predictor Marker of Relapse in Ewing Sarcoma Patients.

Ewing sarcoma (EWS) is a paediatric aggressive malignant tumour of bones and soft tissues. Multidisciplinary chemotherapies, surgical resection, and radiation represent the only strategies counteracting the disease, however spreading and relapse of disease still remain a clinical issue. Circulating tumour cells (CTCs) are an important feature of EWS but the prognostic significance has not been, yet, clarified. CTCs have been found both in patients with localized disease and in those who recur or metastasize. The identification of markers that can detect recurrences and metastasis remains an important challenge for research. Unfortunately, even most of patients with localized cancer relapsed and the reason has not yet been fully understood. In this clinical study on EWS patients, we evaluated the expression of CD99 antigen and beta-3 adrenergic receptor (ß3-AR) on CTCs and bioptic derived cells by flow cytometry. The preliminary data revealed a higher ß3-AR expression on cells derived from metastatic or relapsed patients, suggesting a role for the ß3-AR as a possible predictive maker of disease recurrence in both patients with metastatic and localized disease.

Clinical features, prognostic factors and outcome in a series of 29 extra-skeletal Ewing Sarcoma. Adequate margins and surgery-radiotherapy association improve overall survival.

OBJECTIVE: Authors review a series of 29 extra-skeletal Ewing Sarcoma (EES). METHODS: They analyzed characteristics, prognostic factors and outcome of EES. RESULTS: Authors report 60% Overall Survival (OS) and 56% of Event Free Survival (EFS) at 5 years. Better 5 years EFS was found in patients with localized disease (68.8%) compared to metastatic EES (33.3%) (p = 0.042). Radiotherapy + surgery offered the best local treatment (p=0.017). Volume (p = 0.032), Surgical margins (p = 0.01), metastatic disease (p = 0.0013) were a significant prognostic factor for OS at 5-yrs. CONCLUSION: Adequate margins and surgery+radiotherapy improve Overall Survival.

Latissimus dorsi rotational flap combined with a custom-made scapular prosthesis after oncological surgical resection: a report of two patients.

BACKGROUND: Sarcomas that arise from the scapula or periscapular soft tissues often require a total scapulectomy. This often implies a large complex tissue defect that needs adequate reconstruction of both bone and soft tissue. Although various methods have been developed, no optimal procedure has emerged. Postoperative complications are common and functional recovery is not always satisfactory. This study aims to present a new surgical technique that combines a custom-made scapular prosthesis with a functional latissimus dorsi flap. CASE PRESENTATION: Two patients diagnosed with malignant tumour of the scapular region were surgically treated after proper multidisciplinary evaluation. The first patient underwent the procedure as a first surgery, the second as revision surgery. The new technique comprises three surgical stages: excisional surgery with soft tissue resection and scapulectomy, bone reconstruction with custom-made prosthesis, and soft tissue reconstruction using a latissimus dorsi rotational flap overturned on the prosthesis. The goal is to set up a new functional unit combining an anatomically shaped implant (manufactured using latest three-dimensional printing technology) and a muscular flap, and to maintain the neurovascular supply. The patients were followed up to evaluate functional outcome and complications. Both patients were alive with no evidence of disease. Functional results were satisfactory and the Musculoskeletal Tumor Society scores were 87% and 63%, respectively. No surgical complications such as implant breakage, joint collapse, wound dehiscence, or infection were observed. CONCLUSIONS: This new technique upgrades the role of the latissimus dorsi flap to a functional tool in combination with an anatomical, three-dimensionally printed, custom-made prosthesis, and provides adequate well-vascularized and healthy tissue to maximize the likelihood of successful limb salvage.

Inflammatory Myofibroblastic Tumor of the Tongue. Report of a Pediatric Case and Review of the Literature.

BACKGROUND: Inflammatory myofibroblastic tumor (IMT) is an uncommon mesenchymal lesion composed of myofibroblastic and fibroblastic spindle cells, accompanied by inflammatory infiltration. IMT may occur in the tongue. Five cases have been previously reported at this site. CASE REPORT: An inflammatory myofibroblastic tumor arose in the tongue of a 10 month old infant, confirmed by anaplastic lymphoma kinase (ALK) immunohistochemical staining and the clinical response to the tyrosine kinase inhibitor. CONCLUSIONS: IMT can occur in the tongue. This report highlights the differential diagnosis of IMT. ALK staining is both a helpful diagnostic marker and a predictive marker for targeted therapy in this tumor type.

Central nervous system involvement in children and adolescents with rhabdomyosarcoma. A report from the AIEOP Soft Tissue Sarcoma Committee.

BACKGROUND: Rhabdomyosarcoma (RMS) is a highly malignant tumor typically affecting children and adolescents. Central nervous system (CNS) dissemination is rare in RMS patients, but seems to have a particularly negative impact. The aim of this study was to analyze treatment and outcome of patients with RMS and evidence of CNS disease who were registered in the protocols coordinated by the Italian Soft Tissue Sarcoma Committee from March 1979 to December 2016. METHODS: We analyzed 39 patients with CNS disease. Depending on when their CNS disease was identified, we grouped patients as: Group A, at diagnosis; Group B, progression during treatment; Group C, at first relapse. RESULTS: Six patients were in Group A (2.7% of metastatic RMS patients at diagnosis); 24 were in Group B and 9 in Group C (6.5% of patients with tumor progression/relapse included in the protocols). Only 5 patients (4 in Group A, 1 in Group B) survived the event and are alive in complete remission with a median follow-up of 17.5 years. These 5 patients received systemic chemotherapy and craniospinal radiotherapy, and 2 of them also received intrathecal therapy with topotecan. CONCLUSIONS: CNS involvement at diagnosis is a rare and prognostically negative event in RMS patients, but not always fatal when it is found at diagnosis. It is more frequent during or shortly after treatment, and the more dismal prognosis in these cases underscores the need to improve our ability to identify patients at risk of CNS dissemination in order to attempt more effective treatments that can sterilize the meninges.