A Novel Saliva and Serum miRNA Panel as a Potential Useful Index for Oral Cancer and the Association of miR-21 with Smoking History: a Pilot Study.

Tobacco use is implicated in the carcinogenesis of oral squamous cell carcinoma (OSCC), which is associated with poor survival if not diagnosed early. Identification of novel noninvasive, highly sensitive, and cost-effective diagnostic and risk assessment methods for OSCC would improve early detection. Here, we report a pilot study assessing salivary and serum miRNAs associated with OSCC and stratified by smoking status. Saliva and paired serum samples were collected from 23 patients with OSCC and 21 healthy volunteers, with an equal number of smokers and nonsmokers in each group. Twenty head and neck cancer-related miRNAs were quantified by qPCR (dual-labeled LNA probes) and analyzed by Welch t test (95% confidence interval). Four saliva miRNAs, miR-21, miR-136, miR-3928, and miR-29B, showed statistically significant overexpression in OSCC versus healthy controls (P < 0.05). miR-21 was statistically significantly overexpressed in OSCC smokers versus nonsmokers (P = 0.006). Salivary miR-21, miR-136, and miR-3928, and serum miR-21 and miR-136, showed statistically significant differential expression in early-stage tumors versus controls (P < 0.05), particularly miR-21 in smokers (P < 0.005). This pilot study provides a novel panel of saliva and serum miRNAs associated with oral cancer. Further validation as a potential useful index of oral cancer, particularly miR-21 in smokers and early-stage OSCC is warranted. PREVENTION RELEVANCE: Saliva and serum miR-21, miR-136, miR-3928, and miR-29B, are potentially associated with oral cancer even at an early stage, especially miR-21 in individuals with a smoking history, a further validation in a larger cohort of subjects with premalignant and early malignant lesions need to confirm.