Preoperative platelet-to-lymphocyte ratio and lymphocyte-to-monocyte ratio predict poor prognosis in patients diagnosed with salivary gland adenoid cystic carcinoma.

Background: To assess the prognostic utility of preoperative neutrophil-to- lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) in the peripheral blood of patients diagnosed with salivary adenoid cystic carcinoma (SACC).

Methods: Data from 310 patients diagnosed with SACC between January 2008 and April 2014 were included. Data were acquired from patient medical records and follow-ups. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off values for NLR, PLR, and LMR. Kaplan-Meier and multivariate Cox regression analyses were used to evaluate the impact of NLR, PLR, and LMR on overall survival.

Results: According to ROC curve analysis, the optimal cut-off values for NLR, PLR and LMR were 1.65, 105.13, and 3.38, respectively. A high PLR was significantly associated with cervical lymph node metastasis (P = 0.043), while low LMR was significantly associated with tumor size (P = 0.016). In addition, patients with PLR >105.13 (P < 0.001) and LMR <3.38 (P < 0.001) experienced worse overall survival rates according to univariate analysis. Multivariate Cox proportional hazards regression modeling demonstrated that histological grade, high PLR, and low LMR were independent prognostic factors for overall survival in patients with SACC.

Conclusions: Both pretreatment PLR and LMR were independent predictors of poor prognosis in patients with SACC, and may be considered accurate, low-cost, and readily obtainable clinical prognostic parameters.