Prognosis and clinical presentation

Young age and metastatic disease at presentation are associated with poor outcomes in children with extracranial rhabdoid tumors.

One study that used data from the National Cancer Database identified 202 patients (aged younger than 18 years) with non–central nervous system (CNS) malignant rhabdoid tumors. The primary site of the malignant rhabdoid tumor was soft tissue (46%), kidney (45%), and liver (9%).[132]

A SEER study examined 229 patients with renal, CNS, and extrarenal malignant rhabdoid tumor. Patients aged 2 to 18 years, patients with a limited extent of tumor, and patients who received radiation therapy had favorable outcomes compared with other patients (P < .002 for each comparison). Site of the primary tumor was not prognostically significant. The OS rate was 33% at 5 years.[133]

A European registry for extracranial rhabdoid tumors identified 100 patients from 14 countries between 2009 and 2018.[134] Half of the patients were younger than 1 year at diagnosis. In 30 patients (30%), the tumor was located in the kidneys. Extracranial, extrarenal malignant rhabdoid tumor was found in 70% of patients (70 of 100), and the most common locations were in the cervical region, thoracic region, and liver. Nine patients demonstrated synchronous tumors. Distant metastases at diagnosis were present in 35% of patients (35 of 100). SMARCB1 germline pathogenic variants were detected in 21% of patients (17 of 81 evaluable). The 5-year OS rate was 45.8% (± 5.4%), and the EFS rate was 35.2% (± 5.1%). In an adjusted multivariate model, presence of a germline pathogenic variant, metastasis, and lack of a gross-total resection were the strongest significant negative predictors of outcome.