Outcomes and patterns of failure for sinonasal undifferentiated carcinoma (SNUC): The Mayo Clinic Experience

Background: Sinonasal undifferentiated carcinoma (SNUC) is a rare aggressive disease arising in the nasal cavity and paranasal sinuses with poor prognosis and unclear optimal management. Methods: Forty patients were analyzed. Nasal cavity was the most common primary site. Most patients presented with T4 disease, received trimodality therapy, and were treated with intensity-modulated radiotherapy (IMRT). Results: Median follow-up was 6.9 years. Sixteen patients (40%) experienced recurrent disease, 5 local (12.5%), 1 regional (2.5%), and 10 distant (25%). The 5-year overall survival (OS), recurrence-free survival (RFS), and locoreginal control (LRC) were 44%, 39%, and 71%, respectively. Patients treated with trimodality therapy had better outcomes compared to single modality therapy. Improved OS was noted with IMRT and with doses ≥60 Gy. The most common cause of death was distant metastasis. Conclusion: SNUC is an aggressive malignancy with a high tendency to metastasize. Better outcomes were obtained with a trimodality approach. Modern radiotherapy (RT) techniques and doses ≥ 60 Gy were associated with improved OS.