Low-Dose Radiotherapy and Anti-PD-1 Immunotherapy as Neoadjuvant Treatment for Resectable Locally Advanced Head and Neck Squamous Cell Carcinoma

Over 60% of head and neck squamous cell carcinoma (HNSCC) patients are diagnosed at a locally advanced stage. While standard treatments involve surgery and chemoradiotherapy, prognosis remains poor, with 50-60% experiencing local recurrence within two years. Neoadjuvant therapy can potentially reduce tumor burden, preserve organs, and lower distant metastasis risk. Despite the KEYNOTE-689 trial showing that adjuvant two-cycle pembrolizumab increased major pathological response to 9.8% in stage III-IVB HNSCC, this result remains insufficient. More effective immunotherapy-based combinations are urgently needed to improve long-term survival after neoadjuvant treatment.

Preclinical and clinical evidence indicates that low-dose radiotherapy can activate the tumor immune microenvironment and synergize with immunotherapy. Based on this rationale, the present clinical trial will evaluate a neoadjuvant regimen combining LDRT with two cycles of an anti-PD-1 inhibitor in patients with surgically resectable, locally advanced HNSCC.