Induction chemotherapy followed by concurrent chemotherapy and proton beam for sinonasal undifferentiated carcinoma.

Abstract

e17557 Background: The optimal treatment of sinonasal undifferentiated carcinoma (SNUC) remains to be defined given its aggressiveness and dismal outcome with traditional treatment. We examined the treatment outcomes of SNUC treated with combined proton beam with concurrent chemotherapy +/- induction chemotherapy. Methods: Between 2005 and 2016, 15 patients with SNUC were treated at our institution. All patients had T4 disease, with 20% had nodal involvement and 87% with orbital invasion. Forty-seven percent of patients underwent induction chemotherapy followed by concurrent chemoradiotherapy (sequential group) and 53% underwent or concurrent chemoradiotherapy alone. All patients underwent proton beam for the primary site and upper neck, and photon irradiation for the lower neck. The median dose to the primary site was 70Gy(RBE). Locoreigonal control, freedom from distant metastasis, disease-free survival, and overall survival were estimated by the Kaplan-Meier method. Results: With a median follow-up of 25 months, there were 2 local, 2 regional, 4 distant, and 5 dural-leptomeningeal failures. The 2-year locoregional control rates were 100% and 60% (95%CI:33%-100%) for the sequential and concurrent alone groups, respectively, (p=0.10). The 2-year overall survival was 100% for the sequential group and 58% (95%CI:31%-100%) for the concurrent group (p=0.03). The 2-year distant-metastasis-free survival was 83% (95%CI:58%-100%) and 31% (95%CI:10%-96%) for the sequential and concurrent group, respectively (p= 0.03). Furthermore, the sequential group has a 2-year disease-free survival rate of 100% compared with 58% (95%CI:31%-100%) for the concurrent group (p=0.02). Conclusions: Induction chemotherapy followed by concurrent chemotherapy and proton beam results in promising outcome in patients with SNUC.