Trends and efficacy of definitive radiotherapy regimens for locally advanced head and neck cancer in elderly patients: A population-based analysis by the German cancer registry group

BACKGROUND: With increasing life expectancy, the number of elderly patients diagnosed with locally advanced head and neck squamous cell carcinoma (HNSCC) is rising. The effectiveness of definitive radiotherapy (RT) regimens in this population remains unclear. This study investigates RT regimen trends and their impact on overall survival (OS) and locoregional recurrence (LRR) in elderly HNSCC patients using a large German cancer registry dataset. METHODS: A retrospective analysis of 84,046 HNSCC cases from 2000 to 2022 was conducted. RT administration trends were assessed in patients aged ≤ 70 years and > 70 years. OS and LRR were analyzed in patients receiving definitive RT alone or combined with chemotherapy (RCTx) or cetuximab (RT-Cet), using Kaplan-Meier estimates and multivariate Cox regression models. RESULTS: The proportion of elderly patients receiving definitive RT regimens increased significantly over time. Platinum-based RCTx remained the most frequently used regimen but was less common in patients > 70 years than in younger patients (26 % vs. 57 %, P < 0.001). Five-year OS following platinum-based RCTx was comparable between age groups (HR 1.01, P = 0.83). In contrast, RT-Cet was associated with significantly worse OS and higher LRR compared to platinum-based RCTx, with a stronger negative impact in patients > 70 years (OS: HR 2.31, P < 0.001; LRR: HR 2.11, P = 0.003) than ≤ 70 years (OS: HR 1.55 P < 0.001; LRR: HR 1.43, P = 0.002). This age-related difference was not observed with RT alone. CONCLUSIONS: Platinum-based RCTx remains the most effective treatment for elderly HNSCC patients. RT-Cet is associated with poorer outcome particularly in patients > 70 years, underscoring the need for age-adapted, biology-informed treatment strategies.