Postoperative Adjuvant Chemoradiotherapy ± PD ‐1 Inhibitor for Locally Advanced Head and Neck Squamous Cell Carcinoma

ABSTRACT Background Postsurgical immunotherapy for patients with locally advanced head and neck squamous cell carcinoma (HNSCC) remains elusive. This study assesses the value and significance of postoperative immunotherapy in the treatment of locally advanced HNSCC. Methods In total, 212 patients with locally advanced HNSCC who underwent radical surgery were stratified into three treatment groups: adjuvant radiotherapy alone, adjuvant chemoradiotherapy (CRT), and adjuvant chemoradiotherapy plus immunotherapy (PD‐1 Ab). A comprehensive analysis was conducted to assess survival outcomes and prognostic factors across diverse patient cohorts. Results Four patients were lost to follow‐up, with a follow‐up rate of 98.1% and a median follow‐up time of 41 months (IQR 24–68). A total of 64/212 individuals died, with cancer being the cause of 62 cases and noncancer causes accounting for the remaining two deaths; 62/212 (29.2%) patients experienced relapse and/or metastasis. The 3‐year OS rates for the radiotherapy group, CRT group, and CRT plus PD‐1 Ab group were 54.8%, 75.4%, and 82.2%, respectively. However, no statistically significant difference in OS or PFS was observed between the CRT and CRT + PD‐1 Ab groups ( p all > 0.05), although both were superior to radiotherapy alone ( p all < 0.05). Multivariate analysis indicated that age, smoking history, TNM stage and treatment method were independent prognostic factors for OS ( p all < 0.05). Smoking history and treatment methods were independent prognostic factors for PFS and DMFS ( p all < 0.05). Conclusion PD‐1 Ab may contribute less to tumors with better treatment outcomes from concurrent chemoradiotherapy.