Detection of interleukins-6 and 8 in saliva as possible biomarkers for oral pre-malignant lesions and oral cancer

Background:

Early detection and follow-up are required to improve the morbidity and mortality associated with oral cancer. For this, the need is to explore biomarkers in a diagnostic matrix whose collection is non-invasive, easy to handle, and easily accessible. Additionally, these biomarkers should have high sensitivity and specificity in order to use them in mass screening for early detection.

Recent meta-analyses have advocated that salivary interleukin, IL-6, and IL-8 have the potential to serve as biomarkers for the early detection of PMLs and oral squamous cell carcinoma (OSCC). The metadata, however, reports wide variations in results among the different studies. The reasons cited and observed for the discordant results are multi-fold. They are principally related to study design., viz., sample size, no proper harmonization of confounding variables such as inflammatory conditions, and most importantly no standardization procedure for saliva collection and analysis was ever done and followed for most of the studies. Additionally, there are also varaitons in epigenetic, genetic,environmental, and habit-related risk factors for OSCC, as well as geographical  differences in how salivary biomarkers are expressed. This advocate carefully designed studies in different ethnic groups to explore the discriminatory efficacy of salivary IL-6 and IL-8.

Aim:

To assess the utility and effectiveness of salivary IL-6 and IL-8 levels in the differential diagnosis of potentially malignant lesions (PMLs) and oral squamous cell carcinoma (OSCC) in a high oral cancer prevalence region.

Design:

This observational case-control comparative study will be initiated after appropriate ethical clearance from IEC, AIIMS, Rajkot. Informed consent, to obtain salivary and blood samples will be taken from subjects including, OSCC- early stage (I+II), and advanced stage (III+IV), 50 each, 50 participants each in group PMLs, and healthy controls. Salivary IL-6 and IL-8 levels/concentration will be measured by enzyme-linked immunosorbent assay (ELISA).

Blood samples will be assessed for kidney, liver function tests, and tests for diabetes to rule out any signs of inflammation and HIV will be done to rule out immunocompromised status.

The data will be subjected to appropriate statistical analysis, p-value, receiver operating characteristic curve (ROC), area under the curve (AUC), sensitivity, and specificity.

Novelty/Clinical Utility of the Study:

The study will generate preliminary data on the levels of salivary IL-6 and IL-8 in a particular geographic region with a high prevalence of oral cancer. The applied statistical analysis methods will explore the diagnostic utility of these markers for OSCC/PMLs. If found to have good sensitivity and specificity, they can serve as cost-effective, non-invasive tools, for the diagnosis and screening tools for oral cancer.