Abstract:

Objective To explore the clinical characteristics and prognostic factors of head and neck rhabdomyosarcoma (HNRMS) in children. Methods A retrospective analysis was conducted on the clinical data of children with HNRMS treated in Shanghai Children's Hospital from January 2011 to December 2025. Patients were stratified into different groups according to the following criteria: presence or absence of resectable tumor on imaging following neoadjuvant chemotherapy, presence or absence of viable tumor tissue on histopathology of the delayed primary tumor resection, and presence or absence of residual disease on imaging at the completion of multimodal therapy. The 5-year overall survival (OS) rates were compared between groups. Results A total of 32 pediatric patients with HNRMS were enrolled, including 20 boys and 12 girls. The median age at diagnosis was 48 (36.0-94.0)months. Tumor diameter was >5 cm in 14 patients and ≤5 cm in 18 patients. Distant metastasis occurred in 5 patients (15.6%). The primary tumors were located in the parameningeal region in 15 patients (46.9%), among whom 11 exhibited signs of meningeal involvement; in the orbit in 4 patients (12.5%); and in non-orbital, non-parameningeal sites in 13 patients (40.6%). According to risk stratification, 3 patients (9.4%) were classified as low-risk, 22 (68.7%) as intermediate-risk, and 7 (21.9%) as high-risk. Histopathological subtypes included embryonal in 24 patients, alveolar in 6 patients, and other types in 2 patients. The median follow-up duration for all 32 patients was 62.5 (34.8-82.0) months. The 5-year event-free survival (EFS) and overall survival (OS) rates were both 78.1%±7.8%. The 5-year OS rate for patients with non-metastatic HNRMS was significantly higher than that for patients with metastatic HNRMS (85.2% vs. 40.0%, P=0.020). The 5-year OS rate for PM-RMS was slightly lower than that for RMS in non-parameningeal sites (66.7% vs. 88.2%, P=0.077). PM-RMS with signs of meningeal involvement (11 patients) demonstrated a significantly lower 5-year OS rate compared with RMS in non-parameningeal sites (54.5% vs. 88.2%, P=0.016). Twelve patients with residual disease following neoadjuvant chemotherapy (the residual tumor group) had a significantly lower 5-year OS rate compared with nine patients without residual disease following neoadjuvant chemotherapy (the no residual tumor group) (50.0% vs. 100.0%, P=0.028). Patients without residual disease on imaging at the completion of multimodal therapy had a significantly higher 5-year OS rate than those with residual disease (96.2% vs. 0.0%, P<0.001). Conclusions Children with HNRMS have a favorable overall survival, but those with metastasis or parameningeal site (especially accompanied by signs of meningeal involvement) still have poor prognosis, and new treatment methods need to be explored. Maximal tumor eradication with radiotherapy, chemotherapy, and surgery is critical for successful treatment.

Key words: rhabdomyosarcoma, head and neck, parameningeal, child