3476 - Treatment Paradigms and Patterns of Failure in Locally Advanced Sinonasal Malignancies: A Single-Institution Experience
Presenter(s)
A. C. Gober1, J. Beiriger1, M. Berry1, J. Alt1, H. Mccrary2, and Y. J. Hitchcock3; 1University of Utah, Salt Lake City, UT, 2University of Utah, Salt Lake City, UT, United States, 3Department of Radiation Oncology, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT
Purpose/Objective(s): Despite their high mortality, data regarding improving outcomes in sinonasal malignancies remains limited. Our study aims to evaluate treatment patterns, survival outcomes, and recurrence patterns in patients with locally advanced sinonasal malignancies.
Materials/Methods: Retrospective analysis of patients treated from 2010-2025 for T3-T4 sinonasal tumors was completed, excluding rare histologies such as melanoma, lymphoma, and sarcoma. Groups were stratified by stage, histology, and pathologic features. Oncologic outcomes including progression-free survival (PFS) and overall survival (OS) were analyzed using Chi-square and Fisher's exact tests.
Results: Ninety-four patients were identified, with a median follow-up of 62.7 months. Squamous cell carcinoma (SCC) was the predominant histologic subtype (42.6%), followed by olfactory neuroblastoma (ONB, 27.7%), sinonasal undifferentiated carcinoma (SNUC, 15.9%), and other histologies (13.8%). Clinical T staging was T3 in 26% (n=24), T4a in 40% (n=38), and T4b in 34% (n=32). Clinical nodal disease (cN+) was present in 15 patients.
Sixty-five (69.1%) patients underwent definitive surgical resection. Perioperative treatment in this group included induction chemotherapy (n=2), adjuvant radiation (RT, n=46) and chemoradiation (CRT, n=13). Twenty-two patients were treated with definitive CRT. The median prescription RT dose was 6600 cGy for adjuvant and 7020 cGy for definitive cases. Treatment paradigms differed substantially by histology, with 73% of SNUC patients treated with CRT, whereas SCC and ONB were predominantly managed with surgery followed by adjuvant RT (53% and 65%, respectively). Overall survival was 69.5 months, with a 5-year OS of 54.3%. In multivariable Cox regression adjusting for stage, histology, and nodal status, stage IV disease was independently associated with worse OS (HR 2.59, p=0.048), but T4 disease alone was not. SCC had a lower median survival than ONB or SNUC at 54.4 months. Median PFS was 43.3 months, with 48 patients experiencing disease progression. SCC had the highest recurrence rate (42.5%), predominated by local failure. Stage IV disease was associated with higher progression rates (HR 2.81, p=0.018), while nodal disease and skull base invasion did not impact survival outcomes.Conclusion: Our analysis revealed that multimodality treatment for T3-T4 sinonasal malignancies yielded favorable survival outcomes, comparable to those reported in historical series. In our cohort, ONB demonstrated superior outcomes compared to SCC, and local failure (17.0%) was the most predominant pattern of disease progression across histologic analysis.