Table 1. Property of the included literatures [15-21]
3.2 Impact of PLR on outcome indicators
7 articles evaluated PLR’ s role in the prediction of OS in laryngeal cancer patients. There was powerful connection between high preoperative PLR and poor OS(HR=1.70, 95%CI 1.11-2.61)(Figure.2A). As Table 2 showed, depend on PLR cut-off values, 7 studies were divided into two subgroups and subgroup analysis revealed that patients with high PLR showed a higher mortality than those with a lower PLR (cut-off>114, HR=1.937, 95% CI= 0.942-3.985). When the sample size> 200, the results showed that high PLR in patients with laryngeal cancer was significantly related to OS. (HR = 1.663, 95% CI 1.265-2.186, p= 0.000). According to the results of subgroup analyses, HR of treatment methods was 0.851 (95%CI 0.145-4.989, p = 0.001) for patients with surgery; and patients treated by comprehensive treatment, the HR was 2.067 (95%CI 1.328, 3.216 p = 0.858). Additionally, the results of subgroup analysis that was performed by tumor stage and univariate/multivariate analysis were displayed in Table 2.