Prognostic value of pretreatment lymphocyte percentage in oral cancer: A prospective cohort study

Abstract Objective To assess the prognostic role of pretreatment lymphocyte percentage (LY%) for patients with oral squamous cell carcinoma (OSCC). Methods A large‐scale prospective cohort study between July 2002 and March 2021 was conducted. Propensity score‐matched (PSM) analysis and inverse probability of treatment weighting (IPTW) analysis were performed to adjust for potential confounders. Using random survival forest (RSF), the relative importance of pretreatment LY% in prognosis prediction was also assessed. Results A total of 743 patients were enrolled and followed up (median: 2.75 years, interquartile range: 1.25–4.42 years). A high pretreatment LY% was significantly associated with better disease‐specific survival of patients with OSCC (Hazard ratio [HR] = 0.60, 95% confidence interval [CI]: 0.42, 0.84). The same tendency was observed in PSM (HR = 0.57, 95% CI: 0.38, 0.85) and IPTW analysis (HR = 0.57, 95% CI: 0.40, 0.82). RSF showed that LY% ranked the fifth among importance ranking of all prognostic factors. Conclusion Pretreatment LY% showed a moderate predictive ability, suggesting it might be a valuable tool to predict prognosis for patients with OSCC.