[Parameningeal or non-parameningeal head and neck rhabdomyosarcoma: a study based on propensity score matching and survival analysis].

Objective: To compare the prognoses between parameningeal and non-parameningeal head and neck rhabdomyosarcoma based on propensity score matching and to explore the prognostic factors of overall survival in patients with head and neck rhabdomyosarcoma. Methods: The medical records of 64 patients with pathologically diagnosed as head and neck rhabdomyosarcoma from January 2016 to May 2020 in Peking Union Medical College Hospital were retrospectively retrieved, including 31 males and 33 females, with an average age of (8.0±8.9) years. Kaplan-Meier method was used to draw and compare survival curves in subgroup analysis according to different histopathological characteristics. Patients were divided into non-parameningeal (27 cases) and parameningeal (37 cases) group based on the location of primary lesion. Patients were further selected using 1∶1 propensity score matching method. The basic clinical data and overall survival were compared before and after matching. Prognostic factors were anlysed using Cox's proportional hazards regression model. Results: In 64 patients with head and neck rhabdomyosarcoma, lower risk stratification, and lower TNM stage indicated higher overall survival (all P <0.05). Before matching, patients in parameningeal group presented with higher T stage and IRS (Intergroup Rhabdomyosarcoma Study) staging (all P <0.05). There were no significant differences in basic clinical data and 1-, 2-, and 3-year overall survival rates between two groups after matching( P >0.05). Tumor size smaller than 5 cm, embryonal histology, negative FOXO1 fusion gene, lower risk stratification, and lower TNM stage were associated with higher overall survival (all P <0.05). Among these, tumor size and histology were independent prognostic factors ( HR =2.36, 95% CI :1.07-5.20, P =0.033; HR =5.54, 95% CI: 1.18-25.95, P =0.030). Conclusions: There is no significant difference in overall survival between patients with parameningeal and non-parameningeal rhabdomyosarcomas. Tumor size smaller than 5 cm and embryonal histology are two independent prognostic factors.