Neoadjuvant immunoradiotherapy in patients with locally advanced oral cavity squamous cell carcinoma: a retrospective study

Background: Although anti-programmed death receptor-1 (PD-1) agents have been evaluated in the neoadjuvant setting for the treatment of locally advanced head and neck cancer, including oral cavity squamous cell carcinoma (OCSCC), the overall response rate is modest. The aim of the present study was to evaluate the efficacy and safety of neoadjuvant nivolumab in combination with stereotactic body radiotherapy (SBRT) for the treatment of locally advanced OCSCC.

Methods: OCSCC patients who underwent surgical resection within 6 months of treatment with nivolumab plus SBRT from December 2018 to February 2021 were analyzed retrospectively.

Results: All 30 eligible patients enrolled in this study well tolerated the neoadjuvant treatment with no serious adverse events (AEs). Of them, 27 patients (90.0%) achieved R0 resection, and 5 patients (16.7%) experienced procedure-associated complications. The complete response (CR), partial response (PR) and stable disease (SD) were 10.0%, 46.7% and 43.3% respectively. The major pathological response (MPR), complete pathological response (pCR) and clinical to pathological downstaging rate were 60.0%, 33.3% and 83.3% respectively. During the median follow-up period of 13.5 months, 26 patients (86.7%) who underwent surgical resection remained alive. The disease-free survival (DFS) and overall survival (OS) at 24 months were 70.4% and 76.4% respectively.

Conclusions: Neoadjuvant nivolumab plus SBRT is safe and efficacious, and could be used as a potential neoadjuvant option for the treatment of patients with locally advanced OCSCC.