ESTRO 2023 - Abstract Book

S955

Digital Posters

ESTRO 2023

1 Azienda Ospedaliero-Universitaria Careggi, University of Florence, Radiation Oncology, Florence, Italy; 2 Cyberknife Center, Istituto Fiorentino di Cura ed Assistenza (IFCA), Radiation Oncology, Florence, Italy; 3 University of Florence, Department of Statistic, Computer Science and Applications “G.Parenti”, Florence, Italy; 4 IRCCS Ospedale Policlinico San Martino, Genoa; Health Science Department (DISSAL), University of Genoa, Radiation Oncology , Genoa, Italy; 5 ASST Spedali Civili of Brescia, University of Brescia, Radiation Oncology, Department of Medical and Surgical Specialties, Radiological Science and Public Health, Brescia, Italy; 6 Centro di Riferimento Oncologico di Aviano (CRO) - IRCCS, Radiation Oncology, Aviano, Italy; 7 Ospedale Vito Fazzi, Radiation Oncology, Lecce, Italy; 8 Ospedale San Donato, Radiation Oncology, Arezzo, Italy; 9 University Hospital La Sapienza, Radiation Oncology, Rome, Italy; 10 University Hospital Santa Chiara, Radiation Oncology , Pisa, Italy; 11 Azienda Ospedaliera S. Croce e Carle, Radiation Oncology, Cuneo, Italy; 12 IEO European Institute of Oncology IRCCS, Radiation Oncology, Milan, Italy; 13 Fondazione IRCCS Istituto Nazionale dei Tumori, Radiotherapy 2 Unit, Milan, Italy; 14 Fondazione Policlinico Universitario A. Gemelli IRCCS, Diagnostica per Immagini, Radiation Oncology and Hematology, Rome, Italy; 15 University Hospital of Modena, Radiation Oncology , Modena, Italy; 16 Azienda Ospedaliero-Universitaria Careggi, University of Florence, Radiation Oncology , Florence, Italy; 17 Institute for Cancer Research, Prevention and Clinical Network (ISPRO), Cancer Risk Factors and Lifestyle Epidemiology Unit, Florence, Italy Purpose or Objective Recent epidemiologic trends highlighted a rising incidence of Human Papilloma Virus (HPV) related oropharyngeal squamous cell carcinoma (OPC) in the older population, with projected increase of over 50% in subjects older than 65 years in the next decade. Patients (pts) older than 75 years are considered as “late” elderly. Being largely underrepresented in clinical trials, there is a paucity of data on their disease trajectory. The aim of our work was to assess the pattern of practice in this specific subgroup of pts within the Italian Association of Radiotherapy and Clinical Oncology (AIRO). Materials and Methods This is an observational, retrospective study focused on a 6-year timeframe (2015-2021). Consecutive patients aged >75 years at diagnosis with a histologically-confirmed HPV positive (per p16 immunohistochemistry/HPV DNA-in situ hybridization) OPC deemed amenable to a curatively-intended treatment could be included. Overall survival (OS) was defined as the time from OPC diagnosis to last follow-up or death from any cause. Median OS was estimated by the Kaplan Meyer method. A log-rank test was employed to test whether smoking history, presence of caregiver, employed treatment modality and age (< or > 80 years) correlated with longer OS. Hazard ratios (HR) for the association between the variables of interest and the risk of death were obtained by univariate Cox regression analysis. A p-value <0.05 was considered statistically significant. Acute toxicity was evaluated according to CTCAE v. 5.0 Results A total of 95 patients were included in our study, with a median age of 78 years (table 1). The vast majority had a PS of 0 1 (92.6%), and a locally advanced disease (89.4% in stage III/IV according to TNM 7th edition). As expected, radiotherapy alone was the most common adopted modality. At a median follow-up of 25 months (range: 0-116), 64 patients were alive (67.3%). The one and two-year OS rates were 83% and 75%, respectively, whereas the median OS was not reached (figure 1). Among the tested variables, belonging to the group of age >80 years was associated with a worse OS (p=0.0429; HR for death, 2.15, 95% CI 1.00-4.60), whereas no impact on survival was associated with the smoking history (p=.011), treatment modality (p=0.32) and presence of caregiver (p=0.65). The toxicity profile was acceptable (>G3 toxicity of 29.4%), although 6 patients (6.3%) died due to treatment-related complications. Further analyses on radiation dose, target volumes and pattern of failure will be reported