Predictive value of neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, and systemic inflammatory index for detection of recurrence of pleomorphic adenoma of the major salivary glands: a multicenter study

Objective: The aim of this study was to investigate the correlation among inflammatory biomarkers, such as the systemic immune-inflammation index (SII), the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR), and the recurrence of pleomorphic adenomas (PAs). Study Design: This was a retrospective multicenter study. Six hundred eight patients diagnosed with PA and treated by tumor enucleation were included in the analyses. The patients were extracted from a 20-year database of 2 referral centers (January 2000 to January 2020). Data about age, gender, voluntary habits, tumor characteristics, tumor treatment, and values of NLR, PLR, and SII were collected. A receiver operating characteristic (ROC) curve was used to calculate the optimal cutoff values for SII, PLR, and NLR. A linear regression model (LRM) and a nonlinear logistic regression model (NLRM) were implemented for NLR, PLR, and SII. Results: All 3 inflammatory parameters were statistically significant correlated to the recurrence of the tumor. The best performance was achieved by NLR (cutoff of 2.960) with area under the ROC curve (AUC) = 0.91, accuracy of 96.1%, sensitivity of 78.4% and specificity of 97.2%, PPV = 64.4%, and NPV = 98.6%. LRM and NLRM including all hematological parameters did not improve performance in terms of recurrence detection. Conclusions: The use of 3 inflammatory biomarkers could be a useful tool to predict recurrence of tumor in case of PA ≤ 3 cm. NLR in particular could be sensitive with a cutoff of 2.960. The use of NLR, PLR, and SII could be a good reference point for surgical decision making and follow-up in clinical practice. (Oral Surg Oral Med Oral Pathol Oral Radiol YEAR;VOL:page range)