Saliva IL6 Upregulation As a Potential Indicator of Tobacco-Smoke Associated OSCC and Disease Progression and the Association of Saliva RELA(p65) Upregulation With OSCC Local Invasion in Non-Smokers

PURPOSE Head and neck cancer (HNC) is a devastating disease associated with tobacco smoking. Tobacco smoke-related mRNA phenotypes in HNC were previously documented in vivo and may be differentially expressed in the saliva of smokers with oral squamous cell carcinoma (OSCC) compared with non-smokers or healthy volunteers (HC) and potentially related to tumor progression. METHODS We collected saliva from 30 individuals, including 16 OSCC patients [8 with local metastases (meta+). 8 without metastases (meta-)] and 14 HC of an equal ratio of former smokers and non-smokers and determined the mRNA levels of eleven tobacco and HNC-related genes by qPCR. Immunohistochemical analysis was performed in tissue sections from tumors and matched lymph nodes. RESULTS Saliva IL6 and RELA(p65) mRNAs were overexpressed in OSCC vs. HC ( >2-fold change, P <0.05, by t-test), particularly IL6 in smokers (OSCC smokers vs. HC smokers >10-fold change, P <0.05OSCC smokers vs.OSCC non-smokers >17-fold change P < 0.05). IL6 and NF-κB immunopositivity was significantly higher in meta(+) vs. meta(-) OSCC, especially IL6 in smokers. Saliva Rela(p65) significantly overexpressed in never-smokers with OSCC vs. HC (>4-fold change, P <0.04 AUC: 73-76%, Sensitivity 62-62.5%, by by ROC curve analysis) and significantly correlated with NF-κB nuclear positivity in OSCC, particularly in meta (+) (r >0.84, P <0.02, by Pearson). CONCLUSION Our pilot study indicates saliva IL6 mRNA upregulation for further clinical testing as a potential biomarker of former smokers for oral cancer and disease progression. Our data also suggests the association of saliva RELA(p65) mRNA upregulation with OSCC local invasion in non-smokers. Such a test is paramount to the provision of effective preventive care via early detection of locally invasive OSCC, as well as risk stratification in smokers and their monitoring.