Sinonasal rhabdomyosarcoma: prognostic factors and treatment outcomes.

Background: Despite the improvement in survival of pediatric patients with rhabdomyosarcoma, the outcome of patients with sinonasal rhabdomyosarcoma is poor and has not significantly changed. Since few institutions have extensive experience with sinonasal rhabdomyosarcoma in children and adults, our objective was to determine prognostic factors and treatment outcomes for this rare malignancy.

Methods: A retrospective review was performed of consecutive patients with sinonasal rhabdomyosarcoma treated at our institution from 1992 to 2012. Kaplan-Meier estimates and the log-rank test were performed to determine factors associated with disease recurrence and disease-specific survival.

Results: Initial remission was achieved in 12 of the 16 patients. Age younger than 18 years (n = 9) was a positive prognostic factor, as there were no recurrences (p < 0.01) and no deaths (p < 0.01). The alveolar subtype was a poor prognostic factor, as 4 of the 5 patients with this histology died of disease (p < 0.01), and both patients with initial remission developed recurrence (p < 0.01). Presentation with later tumor-node-metastasis classification of malignant tumors (TNM) stage was also significant for poorer survival, as 2 of the 3 patients with stage IV died of disease (p = 0.05). Patient sex and treatment modality were not significant.

Conclusion: Although the sinonasal region is an unfavorable site for rhabdomyosarcomas, in our series patients younger than 18 years and those with embryonal or botryoid subtypes responded very well to current multimodality treatment. However, a poor prognostic trend is evident in patients with sinonasal alveolar rhabdomyosarcomas, as they appear to present more often with regional and distant metastases, have increased recurrence, and decreased survival.