The Impact of the <scp>G8</scp> Score on Survival Outcomes in Patients With Head and Neck Cancer Undergoing Concurrent Radiotherapy With Cetuximab due to Contraindications With Cisplatin

PURPOSE: Patients unable to receive cisplatin due to age, comorbidities, or reduced performance status are commonly treated with concurrent radiotherapy (RT) and cetuximab. This study evaluated the prognostic significance of the Geriatric 8 (G8) score and the Charlson Comorbidity Index (CCI) in predicting survival outcomes in this population. METHODS: We retrospectively analyzed data from 52 patients with locally advanced or loco-regional recurrent head and neck squamous cell carcinoma (HNSCC) who were treated with RT and cetuximab between 2011 and 2024. Patients with p16-positive oropharyngeal or nasopharyngeal cancers were excluded. Overall survival (OS) and cancer-specific survival (CSS) were assessed according to G8 and CCI scores using ROC analysis, Kaplan-Meier curves, and Cox regression. RESULTS: The median follow-up was 50 months. A G8 cut-off of 9.75 was identified (AUC: 0.713, p < 0.01). Patients with G8 ≥ 9.75 showed significantly improved OS (median: 47 vs. 7 months, p < 0.01) and 4-year CSS (66% vs. 32%, p < 0.01). In the definitive treatment group, 4-year CSS was 68% in high-G8 patients vs. 42% in low-G8 patients. In the recurrence group, 4-year CSS was 63% among high-G8 patients, whereas no patient with a low G8 score survived beyond 4 years. Multivariate analysis identified G8 < 9.75 (HR: 4.72, p < 0.01) and RT dose < 60 Gy (HR: 3.01, p = 0.01) as independent predictors of poor OS. No significant association was observed between CCI and survival. CONCLUSION: The G8 score is a valuable prognostic tool for cisplatin-ineligible HNSCC patients treated with RT and cetuximab. Low G8 scores were strongly associated with worse outcomes, highlighting the need for alternative therapeutic strategies in this high-risk subgroup.