ESTRO 2025 - Abstract Book

S1143

Clinical – Head & neck

ESTRO 2025

4493

Digital Poster Squamous cell carcinoma of nasal vestibule: the prognostic role of the four staging system classifications Stefano Durante 1 , Rita De Bernardinis 2 , Andrea Vavassori 1 , Lorenzo Colombi 1 , Marta Tagliabue 3 , Daniela Alterio 1 , Mohseen Ansarin 4 , Barbara Alicja Jereczek-Fossa 5,6 1 Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy. 2 Department of Otolaryngology-Head and Neck Surgery, EO-European Institute of Oncology IRCCS, Milan, Italy. 3 Department of Otolaryngology-Head and Neck Surgery, IEO-European Institute of Oncology IRCCS, Milan, Italy. 4 Division of Otolaryngology and Head and Neck Surgery, EO European Institute of Oncology, IRCCS, Milan, Italy. 5 Division of Radiation Oncology, IEO-European Institute of Oncology, IRCCS, Milan, Japan. 6 Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy Purpose/Objective: Squamous cell carcinoma of the nasal vestibule (SCC-NV) is a rare malignancy with multiple staging systems for its classification. The TNM classifications of the Union for International Cancer Control (UICC) for sinonasal tumors (8th ed.) and non-melanoma skin cancers (8th ed.), the Wang classification, and the recently introduced "Rome" classification by Bussu et al. provide varied prognostic stratifications. Evaluating their prognostic value remains critical for optimizing treatment strategies. This study aims to assess the prognostic significance of these four classification systems in patients with nasal vestibule carcinoma Material/Methods: A retrospective, monocentric study was conducted on a cohort of patients with a primary SCC-NV who were treated at the European Institute of Oncology (IRCCS) in Milan, Italy, between February 2010 and April 2024. Patients were staged in accordance with all currently available staging systems. Overall survival, disease-free survival, and local control were computed using the Kaplan–Meier method. Logistic regression models were employed to correlate survival outcomes with clinical and pathological variables. Results: A total of 79 patients were included in the study, of whom 50 underwent surgical treatment (63.3%), 13 received external beam radiotherapy (16.5%), 16 were treated with brachytherapy (20.2%), and one patient received a combination of external beam radiotherapy and subsequent brachytherapy. The five-year locoregional control (LRC), disease-free survival (DFS), and overall survival (OS) rates were 68.4%, 65.4%, and 71.8%, respectively. A statistically significant correlation was identified between classification systems and survival outcomes. The "Rome" classification demonstrated superior stratification for LC and OS compared to UICC-based systems. Tumour diameter and cartilage infiltration were found to have independent prognostic significance for DFS and OS (p < 0.05). Conclusion: The "Rome" classification may prove to be a valuable tool for improving prognostic stratification in the context of nasal vestibule carcinoma. It would be beneficial for future staging systems to consider integrating additional parameters, such as tumour diameter and infiltration patterns, in order to enhance prognostic accuracy. Further validation in larger cohorts is recommended.

Keywords: nasal vestibule squamocellular carcinoma