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.