Parameningeal (PM) site is a well-known adverse prognostic factor in children with localized rhabdomyosarcoma (RMS). To identify risk factors associated with outcome at this site, we pooled data from 1105 patients treated in 10 studies conducted by European and North American cooperative groups between 1984 and 2004. Clinical factors including age, histology, size, invasiveness, nodal involvement, Intergroup Rhabdomyosarcoma Study (IRS) clinical group, site, risk factors for meningeal involvement (MI), study group, and application of radiotherapy (RT) were studied for their impact on event-free and overall survival (EFS and OS). Ten-year EFS and OS were 62.6 and 66.1% for the whole group. Patients without initial RT showed worse survival (10-year OS 40.8% versus 68.5% for RT treated patients). Multivariate analysis focusing on 862 patients who received RT as part of their initial treatment revealed four unfavorable prognostic factors: age 10 years, signs of MI, unfavorable site, and tumor size. Utilizing these prognostic factors, patients could be classified into different risk groups with 10-year OS ranging between 51.1 and 80.9%. While, in general, PM localization is regarded as an adverse prognostic factor, the current analysis differentiates those with good prognosis (36% patients with 0–1 risk factor: 10-year OS 80.9%) from high-risk PM patients (28% with 3–4 factors: 10-year OS 51.1%). Furthermore, this analysis reinforces the necessity for RT in PM RMS.

Rhabdomyosarcomas (RMSs) are the most common soft tissue sarcomas in children/adolescents less than 18 years of age with an annual incidence of 1-2/million. Inter/intra-tumour heterogeneity raise challenges in clinical, pathological and biological research studies. Risk stratification in European and North American clinical trials previously relied on clinico-pathological features, but now, incorporates PAX3/7-FOXO1-fusion gene status in the place of alveolar histology. International working groups propose a coordinated approach through the INternational Soft Tissue SaRcoma ConsorTium to evaluate the specific genetic abnormalities and generate and integrate molecular and clinical data related to patients with RMS across different trial settings. We review relevant data and present a consensus view on what molecular features should be assessed. In particular, we recommend the assessment of the MYOD1-LR122R mutation for risk escalation, as it has been associated with poor outcomes in spindle/sclerosing RMS and rare RMS with classic embryonal histopathology. The prospective analyses of rare fusion genes beyond PAX3/7-FOXO1 will generate new data linked to outcomes and assessment of TP53 mutations and CDK4 amplification may confirm their prognostic value. Pathogenic/likely pathogenic germline variants in TP53 and other cancer predisposition genes should also be assessed. DNA/RNA profiling of tumours at diagnosis/relapse and serial analyses of plasma samples is recommended where possible to validate potential molecular biomarkers, identify new biomarkers and assess how liquid biopsy analyses can have the greatest benefit. Together with the development of new molecularly-derived therapeutic strategies that we review, a synchronised international approach is expected to enhance progress towards improved treatment assignment, management and outcomes for patients with RMS.

Physical fitness and psychosocial function is often reduced in children during or shortly after cancer treatment. This study evaluates the effect of a combined physical exercise and psychosocial intervention on cardiorespiratory fitness, muscle strength, body composition, psychosocial function and health-related quality of life (HrQoL). In addition, intervention mediators, applicability and adherence were examined. This multicenter randomized controlled trial included 68 children with cancer [mean age 13.2 (SD: 3.1) years; 54% male] during treatment or within 12-months post-treatment. The 12-week intervention consisted of 24 individual physical exercise sessions supervised by a physiotherapist, and 6 psychosocial training sessions for children and 2 for parents. Physical fitness and psychosocial function were assessed at baseline, directly post-intervention and at 12 months’ post-baseline. Generalized estimating equations were used to simultaneously assess intervention effects at short and long-term. Additionally, we evaluated within-group differences over time. Potential physical and psychosocial mediators in the intervention effect on HrQoL were examined using the product-of-coefficient test. Applicability and adherence were assessed by trainer-report. This study was able to compare 26 children who received the study intervention, with 33 children who received usual care. No significant differences in the effects of the intervention were found on physical fitness and psychosocial function at short-term. At 12-months follow-up, significantly larger improvements in lower body muscle strength (β = 56.5 Newton; 95% CI: 8.5; 104.5) were found in the intervention group when compared to the control group. Within-group changes showed significant improvements over time in HrQoL and bone density in both groups. Intervention effects on HrQoL were not significantly mediated by physical fitness and psychological function. Intervention applicability was satisfactory with an average session attendance of 67% and 22% dropout (mainly due to disease recurrence). This 12-week physical exercise and psychosocial training intervention for children with cancer was applicable and showed satisfactory adherence. We found no significant between-group differences in effect, except for a significant improvement in lower body muscle strength at long-term in the intervention group compared to the control group. Yet, both the intervention and the control group showed improvements in bone mineral density and HrQoL over time. The trial was registered at the Dutch Trial Registry ( NTR1531 ). Registered 12 November 2008.