Prognostic value of platelet-to-lymphocyte ratio in patients with oral squamous cell carcinoma: a systematic review and meta-analysis

Numerous studies have investigated the predictive significance of the platelet-to-lymphocyte ratio (PLR) in oral squamous cell carcinoma(OSCC). However, the results of studies on its prognostic value remain controversial. This study aims to evaluate the prognostic significance of the PLR in patients with OSCC. We conducted a comprehensive search of PubMed, Embase, the Cochrane Library, and Web of Science databases for all studies investigating the association between PLR and prognosis in OSCC, from the inception of each database up to November 2023. The outcome measures included overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS). To identify potential sources of heterogeneity, sensitivity and subgroup analyses were performed, alongside an assessment of publication bias. The analyses in this study were conducted using RevMan and Stata software. According to the inclusion criteria, 20 articles were included, including 5,714 patients.The meta-analysis revealed that an elevated PLR adversely affects OS (HR = 1.58; 95% CI: 1.29–1.94; p < 0.0001), DFS (HR = 1.71; 95% CI: 1.20–2.42; p < 0.003), and DSS (HR = 2.41; 95% CI: 1.79–3.25; p < 0.00001). The results of the subgroup analysis showed that a preoperative high PLR was associated with reduced OS when the PLR threshold was ≤ 150 (HR = 1.49, P = 0.0003).When the PLR threshold was > 150, Preoperative PLR was not significantly associated with the prediction of overall survival (OS) in OSCC. (P > 0.05). The prognostic significance of PLR in patients with oral cancer is evident in terms of OS, DSS, and DFS. Nonetheless, it is crucial to note that the predictive value of PLR might depend on specific threshold values.