Multimodality Treatment Outcome in Adult Patients with Head and Neck Rhabdomyosarcoma.

Abstract

Objective(s): Head and neck rhabdomyosarcoma (HNRMS) is a rare malignant tumor in adults. No standard treatment for adults with HNRMS currently exists.

Methods: A retrospective study of 72 newly diagnosed consecutive adult patients with HNRMS was conducted at one institution between November 2010 and April 2023. The log-rank tests were used to compare the differences in survival between treatment groups, and overall survival (OS), local recurrence-free survival (LRFS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) were calculated using the Kaplan-Meier method. We used restricted cubic spline models fitted for Cox proportional hazards models to determine the association between chemotherapy cycles/radiotherapy dose and mortality.

Results: The 2-year OS, PFS, LRFS, and DMFS rates for the entire cohort were 51.0%, 39.2%, 44.3%, and 47.3%, respectively. Radiotherapy significantly improved the OS (p < 0.01), PFS (p < 0.01), LRFS (p < 0.01), and DMFS (p < 0.01). Surgery had no effect on OS (49.3% vs. 53.0%, p = 0.62), PFS (36.9% vs. 41.8%, p = 0.31), LRFS (41.6% vs. 47.4%, p = 0.27), or DMFS (44.4% vs. 50.2%, p = 0.43). The restricted cubic spline showed that eight (HR = 1.002, 95% CI: 0.996-1.007) cycles of chemotherapy and 62.5Gy radiation therapy resulted in the lowest mortality.

Conclusion: For HNRMS, eight cycles of chemotherapy and 62.5Gy of radiation might be sufficient. Poor response to chemotherapy predicted an extreme worse outcome. Surgery played a limited role in the treatment.

Level of evidence: III Laryngoscope, 2024.