LAUSR

Objective Inflammation is related to the occurrence and development of various cancers. This study was designed to explore the role of peripheral blood platelet count, neutrophil-lymphocyte ratio (NLR), platelet count-lymphocyte count ratio (PLR), systemic inflammation index (SII), and other inflammatory markers in predicting benign and malignant Thyroid Imaging Reporting and Data System (TI-RADS) grade 3 thyroid nodules. Methods In this retrospective study, 514 patients with TI-RADS grade 3 thyroid nodules were enrolled. According to the pathological results, the patients were divided into the benign and malignant nodule groups. We compared the clinical characteristics between the two groups and analysed the influencing factors for malignant thyroid nodules by univariate and stepwise multivariate logistic regression analyses and then analysed the cutoff value of each influencing factor according to the receiver operating characteristic curve. Results The leukocyte count, neutrophil count, platelet count, NLR, PLR, and SII of the malignant nodule group were significantly higher than those of the benign nodule group (P < 0.05), the age and the diameter of nodule of the malignant nodule group were significantly smaller than those of the benign nodule group (P < 0.05). After excluding the influence of confounding factors, SII (odds ratio (OR) = 1.006; 95% confidence interval (CI) = 1.003–1.008; P < 0.001), PLR (odds ratio (OR) = 0.981; 95% confidence interval (CI) = 0.981–0.992; P < 0.05), leukocyte count (odds ratio (OR) = 0.654; 95% confidence interval (CI) = 0.466–0.892; P < 0.05), and age (OR = 0.969; 95% CI = 0.954–0.985; P < 0.001) were independent risk factors for malignant thyroid nodules, and the cutoff value of SII and PLR in predicting benign and malignant thyroid nodules were 545.63 × 109/L and 138.63. Conclusion This study showed that peripheral blood SII, PLR, leukocyte count and age were independent risk factors for malignant thyroid nodules, and the combination of these can better predict benign and malignant thyroid nodules, which can further guide the diagnosis and treatment of TI-RADS grade 3 thyroid nodules.