Frequency of circulating CD14 ++ CD16 + intermediate monocytes as potential biomarker for the diagnosis of oral squamous cell carcinoma.

BACKGROUND: Monocytes, which subdivided into three functional subsets (classical, intermediate, and nonclassical), play important roles in the progression of cancer. The subset composition is altered in several pathologic conditions including cancers. However, the composition and function of circulating monocyte subsets in patients with oral squamous cell carcinoma (OSCC) are still obscure.

METHODS: The frequencies of monocyte subsets in peripheral blood of patients with OSCC and healthy donors are determined by flow cytometry, and their diagnostic values for OSCC were evaluated. The associations between levels of monocyte subsets and clinicopathological features of patients with OSCC were analyzed using cross-tabulation with the chi-square test.

RESULTS: We demonstrated that the frequency of CD14++ CD16+ intermediate monocytes was remarkably increased (P < 0.0001) in OSCC patients compared with healthy controls (7.33% ± 2.56% of total monocytes, n = 68 versus 4.78% ± 1.50% of total monocytes, n = 57). A trend of decrease in CD14++ CD16- classical subset was observed between these two groups (P = 0.0508), whereas no significant difference was detected in CD14+ CD16++ nonclassical subset (P > 0.05). The receiver operating characteristic (ROC) curve analysis indicated that the frequency of intermediate monocytes (AUC = 0.810, P < 0.0001) could be a potential diagnostic biomarker to discriminate patients with OSCC from healthy subjects. Moreover, this parameter was significantly correlated to the worst pattern of invasion (WPOI, P < 0.05) of OSCC tissues.

CONCLUSIONS: Detection of monocyte subsets in peripheral blood sheds a light on utilizing the frequency of intermediate monocytes as a potential diagnostic biomarker for OSCC.