Dynamics of coagulation indices around neoadjuvant immunochemotherapy predict response and prognosis in locally advanced OSCC

Oral squamous cell carcinoma (OSCC) is frequently accompanied by a hypercoagulable state. This study aimed to characterize dynamic changes in coagulation indices before and after neoadjuvant immunochemotherapy (NICT) and to assess their associations with postoperative pathological response and survival outcomes. We retrospectively collected conventional coagulation indices and thromboelastography (TEG) parameters for patients with primary locally advanced OSCC ( n = 67) who were treated with NICT followed by surgery at the Hospital of Stomatology, Sun Yat-sen University between January 2023 and June 2025. Temporal changes before and after NICT were analyzed and their associations with pathological response were evaluated. Follow‑up outcomes were recorded, and Kaplan-Meier and multivariable Cox analyses were performed for overall survival (OS) and event-free survival (EFS). Compared with baseline, platelet count (PLT), fibrinogen (FIB), and TEG-derived maximum amplitude (MA) decreased significantly after NICT, while prothrombin time (PT) and activated partial thromboplastin time (APTT) were shortened. Before NICT, patients who did not achieve a major pathological response (non-MPR) had higher PLT and FIB levels than those who achieved a major pathological response (MPR), together with a longer TEG reaction time (R). After NICT, the non‑MPR group continued to exhibit higher PLT and FIB, along with a higher G value, indicating a more overt hypercoagulable phenotype. Survival analyses stratified by ΔNICT trend showed that increases in MA and G were associated with shorter OS. A decrease in K time and increases in Angle, MA, G, and CI were associated with shorter EFS. In multivariable Cox analyses, an increase in MA remained associated with OS and EFS. In OSCC, the coagulation profile generally tends to normalize after NICT. Coagulation indices before and after treatment are associated with pathological response, and a rising MA trend during NICT may be associated with worse survival outcomes.