Allen-Rhoades, Wendy A

Rhabdomyosarcoma is the most common soft tissue sarcoma diagnosed in children and adolescents. Patients that are diagnosed with advanced or relapsed disease have exceptionally poor outcomes. The Children’s Oncology Group (COG) convened a rhabdomyosarcoma new agent task force in 2020 to systematically evaluate novel agents for inclusion in phase 2 or phase 3 clinical trials for patients diagnosed with rhabdomyosarcoma, following a similar effort for Ewing sarcoma. The task force was comprised of clinicians and basic scientists who collectively identified new agents for evaluation and prioritization in clinical trial testing. Here, we report the work of the task force including the framework upon which the decisions were rendered and review the top classes of agents that were discussed. Representative agents include poly-ADP-ribose polymerase (PARP) inhibitors in combination with cytotoxic agents, mitogen-activated protein kinase (MEK) inhibitors in combination with type 1 insulin-like growth factor receptor (IGFR1) inhibitors, histone deacetylase (HDAC) inhibitors, and novel cytotoxic agents.

Abstract Purpose To determine the impact of surgery and/or radiation therapy on distant metastatic sites (DMS) in children with stage IV rhabdomyosarcoma (RMS). Methods A retrospective chart review was conducted on all patients with stage IV RMS at Texas Children's Hospital from 1992 to 2012. Data analyzed included age, gender, primary site, histologic subtype, number and sites of metastases, treatment including local therapy to DMS, and Oberlin score. Results The 5‐year progression‐free survival (PFS) and overall survival (OS) rates were 20% and 25%. The 5‐year PFS in patients receiving local therapy to all DMS (n = 16) and to less than all DMS (n = 19) was 31.3% versus 0% ( P = 0.002), whereas the 5‐year OS was 37.3% versus 0% ( P < 0.001), respectively. The 5‐year PFS in patients with isolated lung metastasis versus other types of metastasis was 29% versus 7% ( P = n.s.), whereas the 5‐year OS was 43% versus 10% ( P = 0.01). The 5‐year pulmonary local control was improved by the use of whole lung irradiation (WLI; 56% vs. 10%, P = 0.03). Conclusions Local treatment to all metastatic sites was associated with improved PFS and OS at 5 years. The use of WLI improved pulmonary control in patients with lung metastasis. We recommend an aggressive approach including local therapy to DMS in children with stage IV RMS.