Survival and Pathological Outcomes of Neoadjuvant Chemoimmunotherapy Followed by Surgery in Locally Advanced Oral Squamous Cell Carcinoma

IntroductionThe prognosis of advanced oral squamous cell carcinoma (OSCC) remains poor, with a 5-year survival rate below 50%. While immune checkpoint inhibitors have improved outcomes in recurrent or metastatic head and neck squamous cell carcinoma, the efficacy of preoperative chemoimmunotherapy for locally advanced OSCC remains under investigation. This study aimed to evaluate pathological responses and survival outcomes in OSCC patients receiving neoadjuvant chemoimmunotherapy followed by surgery.MethodsIn this retrospective cohort study, 30 patients with stage III-IV OSCC were treated with one of two induction regimens: toripalimab plus gemcitabine and cisplatin, or tislelizumab with nab-paclitaxel, cisplatin, and low-dose radiotherapy. All patients underwent radical resection after two cycles. Pathological response was assessed based on residual viable tumor (RVT) proportion. Radiologic response was evaluated per RECIST 1.1. Survival analysis was performed using Kaplan-Meier methods.ResultsThe pathological complete response (pCR) and major pathological response (MPR) rates at the primary site were both 30.0%. Achieving a radiologic partial response was significantly associated with achieving an MPR (P=0.018). With a median follow-up of 28.5 months, the 3-year overall survival (OS) and disease-free survival (DFS) rates were 80.9% and 65.0%. Patients achieving a pPR or better had significantly improved OS (P=0.007) and DFS (P=0.023). Lymph node metastasis, particularly ≥3 positive nodes, was strongly associated with poor survival (P<0.001). A stromal fibroblast proportion ≥70% correlated with better OS (P=0.023).ConclusionNeoadjuvant chemoimmunotherapy followed by surgery yields promising pathological responses and survival outcomes in locally advanced OSCC. The degree of pathological response and lymph node status are critical prognostic factors. Notably, pCR does not universally guarantee favorable outcomes, underscoring the need for vigilant postoperative monitoring.