3490 - Outcomes of Neoadjuvant Chemo-immunotherapy Followed by Radical Surgery vs. Definitive Chemoradiotherapy in Patients with T4b Head and Neck Squamous Cell Carcinoma
Presenter(s)
A. He; sun yet university cancer center, guangzhou, Guangdong, China
Purpose/Objective(s): The optimal management for cT4b head and neck squamous cell carcinoma (HNSCC) remains highly controversial, as these cases are traditionally deemed technically unresectable. While definitive chemoradiotherapy (CRT) is a standard of care, its efficacy in cT4b disease is often constrained by anatomical boundaries and dose-volume limitations. With the emergence of neoadjuvant chemo-immunotherapy, the potential for surgical conversion has expanded. This study aimed to evaluate the clinical impact of integrating radical surgery into the multi-modal framework and to identify whether surgical intervention provides superior local control compared to definitive CRT in this historically recalcitrant population.
Materials/Methods: We retrospectively reviewed 46 patients with cT4b HNSCC treated between 2018 and 2025. Following neoadjuvant chemo-immunotherapy, patients were stratified into a Surgery Group (n=20) and a definitive CRT Group (n=26). Primary endpoints included local control rate (LCR), progression-free survival (PFS), and overall survival (OS). Multivariate Cox regression using Firth’s penalized likelihood was employed to identify independent prognostic factors and minimize bias arising from the limited sample size.
Results: At a median follow-up of 35 months, the Surgery Group demonstrated significantly superior local control. Multivariable analysis identified treatment modality as an independent prognostic factor for LCR; the CRT Group exhibited a 5.04-fold higher risk of local recurrence compared to the Surgery Group (HR = 5.04, 95% CI: 1.18–35.63, P = 0.027). While OS showed marginal significance (P = 0.054), the Surgery Group exhibited a strong trend toward improved PFS (HR = 3.48, 95% CI: 0.97–16.75, P = 0.056). Notably, achieving R0 resection was a critical protective factor for both LCR (HR = 7.79, P = 0.049) and PFS (HR = 8.46, P = 0.040).
Conclusion: In the era of neoadjuvant immunotherapy, radical surgery serves as a critical consolidative component for responsive cT4b HNSCC, offering significantly better local control than definitive CRT. Our findings suggest that for patients achieving surgical resectability after induction therapy, surgical intervention should be prioritized to mitigate the high risk of local recurrence. These results support a tailored multi-modal decision-making process to optimize oncological outcomes for initially unresectable cT4b HNSCC.