Time-dependent prognostic value of perioperative changes in the systemic inflammation response index for overall survival in oral tongue squamous cell carcinoma: a retrospective cohort study.

OBJECTIVES: To investigate the association between perioperative changes in the systemic inflammation response index (SIRI) and overall survival (OS) in patients with oral tongue squamous cell carcinoma (OTSCC), with a focus on its time-dependent prognostic value. MATERIALS AND METHODS: This single-center retrospective cohort study included 264 patients with primary OTSCC who underwent curative-intent resection between June 2015 and February 2025. ΔSIRI was defined as postoperative SIRI minus preoperative SIRI. Time-dependent receiver operating characteristic (ROC) analysis was used to derive the ΔSIRI cutoff. Survival analyses included Kaplan-Meier curves, Cox regression, restricted mean survival time (RMST), and time-varying coefficient Cox models. RESULTS: During follow-up, 70 deaths occurred. In multivariable Cox analysis, high ΔSIRI was significantly associated with poorer OS (adjusted hazard ratio [HR] = 2.13, 95% confidence interval [CI]: 1.24-3.67, P = 0.006). Adjusted RMST analysis showed an 8.02-month reduction in restricted mean survival time in the high ΔSIRI group within 60 months compared with the low ΔSIRI group (95% CI: - 12.76 to - 3.28, P < 0.001). The time-varying coefficient Cox model indicated that the adverse prognostic association of high ΔSIRI was most pronounced during the early follow-up period and gradually attenuated over time. CONCLUSIONS: High perioperative ΔSIRI was associated with poorer OS in patients with OTSCC. ΔSIRI may serve as an adjunctive dynamic inflammatory-immune marker for early postoperative risk stratification, although external validation is warranted. CLINICAL RELEVANCE: Perioperative ΔSIRI may provide supplementary information for identifying patients with OTSCC at higher early postoperative mortality risk.