Investigation and identification of potential biomarkers in human saliva for the early diagnosis of oral squamous cell carcinoma

Background: Oral cancer is 1 of the 6 most common human cancers, with an annual incidence of >300,000 cases worldwide. This study aimed to investigate potential biomarkers in human saliva to facilitate the early diagnosis of oral squamous cell carcinoma (OSCC).

Methods: Unstimulated whole saliva obtained from OSCC patients (n=30) and apparently healthy individuals (n=30) were assayed with ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) in hydrophilic interaction chromatography mode. The data were analyzed using a nonparametric Mann-Whitney U test, logistic regression, and the receiver operating characteristic (ROC) to evaluate the predictive power of each of 4 biomarkers, or combinations of biomarkers, for OSCC screening.

Results: Four potential salivary biomarkers demonstrated significant differences (P<0.05) in concentrations between patients at stages I-II and the healthy individuals. The area under the curve (AUC) values in control vs OSCC I-II mode based on choline, betaine, pipecolinic acid, and l-carnitine were 0.926, 0.759, 0.994, and 0.708, respectively. Four salivary biomarkers in combination yielded satisfactory accuracy (0.997), sensitivity (100%), and specificity (96.7%) in distinguishing OSCC I-II from control.

Conclusions: Salivary metabolite biomarkers for the early diagnosis of OSCC were verified in this study. The proposed approach is expected to be applied as a potential technique of preclinical screening of OSCC.