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 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.