Risk Factors for Survival in Pediatric Maxillofacial Rhabdomyosarcoma: A Single-Center Retrospective Cohort Study

Maxillofacial rhabdomyosarcoma (RMS) is a rare and poorly defined subset of pediatric head and neck RMS. Its anatomical complexity and overlap between parameningeal and nonparameningeal sites pose significant challenges in risk stratification and treatment.

The purpose of the study was to estimate and identify risk factors for the 5-year overall survival (OS) and event-free survival (EFS) among pediatric patients with rhabdomyosarcoma.

This retrospective cohort study was conducted at Beijing Children's Hospital between July 2016 and April 2023. The sample included subjects under 18 years old with a primary diagnosis of maxillofacial RMS. Exclusions included unconfirmed histopathology, primary tumors outside the defined region, incomplete records, or follow-up of <3 months unless due to death.

A set of heterogeneous risk factors were evaluated and grouped into demographic variables, tumor characteristics, and treatment factors.

The main outcome variables were therapeutic outcomes defined as OS and EFS, calculated from the date of diagnosis to the last follow-up visit, death, or first event.

Not applicable.

Survival analyses were performed using the Kaplan-Meier method, and subgroup differences were compared via the log-rank test. Cox proportional hazards regression models were utilized to estimate and identify risk factors associated with outcomes. The level of statistical significance was set at P < .05.

The sample comprised 46 subjects. The median (interquartile range) age was 70.5 (42.3 to 111.5) months. With a median (interquartile range) for follow-up of 51.4 (37.9 to 81.6) months, the 5-year OS and EFS were 70.2 and 66.0%, respectively. Local relapse was the most common pattern of treatment failure (50.0% of events). Multivariable Cox regression indicated that a lack of response to neoadjuvant chemotherapy (SD/PD) was a highly significant independent risk factor for both poor OS and EFS, while positive FOXO1 fusion status remained an independent risk factor for inferior EFS.

Pediatric maxillofacial RMS represents a distinct subgroup with a prognosis intermediate to that of other head and neck subsites. Outcomes are heavily influenced by early chemotherapy response, as well as tumor biology.