ESTRO 2022 - Abstract Book

S940

Abstract book

ESTRO 2022

Conclusion We propose a simple model using only baseline variables, and corrected for overfitting, which predicts dysphagia at 1 year (assessed via water test). Although the major factor for failing WT at 1 year is the pre-treatment test result, it is important to consider other factors when initially discussing treatment as suggested by our model. We find a novel association with HPV status independent of disease stage or location, suggesting a possible underlying variation in response to radiotherapy related to HPV infection. After external validation, this simple model could be used during patient consultations to personalise discussion of possible side effects.

PO-1107 miR-9 as predictor of response to Radiotherapy and Cetuximab in patients with head and neck cancers

G. Fanetti 1 , L. Musco 2 , F. Citron 2 , I. Segatto 2 , F. Micciché 3 , I. Turturici 1 , V. Lupato 4 , F. Matrone 1 , V. Giacomarra 4 , L. Barzan 4 , G. Franchin 1 , G. Baldassarre 2 1 Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, Division of Radiation Oncology, AVIANO, Italy; 2 Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, Division of Molecular Oncology, AVIANO, Italy; 3 Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Polo Scienze Oncologiche ed Ematologiche, Division of Radiation Oncology, Rome, Italy; 4 General Hospital “Santa Maria degli Angeli”, Division of Otolaryngology, Pordenone, Italy Purpose or Objective Cetuximab (CTX) is an anti-EGFR monoclonal antibody and demonstrated to improve survival with respect to radiotherapy (RT) alone in patients (pts) with head and neck squamous cell carcinoma (HNSCC). RT+CTX resulted inferior in comparison to standard chemoradiation (CRT) in HPV+ pts and represents an option for HNSCC pts who are unfit to standard CRT with curative intent. Biomarkers of efficacy are lacking, resulting in many pts treated with disappointing results and unnecessary toxicities. MicroRNA (miR) expression is altered in tumors, and their deregulation is a useful tool to predict oncologic outcome. In HNSCC, several miRs are differentially expressed with respect to the normal/peritumoral mucosa and we found that a four-miR signature (miR-1, -9, -133, and -150) efficiently identifies HNSCC pts at high risk of loco-regional recurrence. This study aims to evaluate the role of miR-9 as biomarker of efficacy of RT+CTX in terms of relapse free survival (RFS). Materials and Methods We reviewed retrospectively 35 pts with HNSCC treated at our Institutions between 2012 and 2017. Inclusion criteria were: histologic proof of HNSCC, primary tumor originating from oropharynx (OP), hypopharynx (HP) and larynx (L), pts treated with curative intent with a total RT dose of 70 Gray with concomitant CTX. Induction chemotherapy and surgery were