Introduction: Introduction: Oral squamous cell carcinoma (OSCC) comprises more than 90% of oral cavity cancer with a high mortality rate. The five-year survival rate for OSCC is around 85% in early diagnosis, but the patients are referred when they develop advanced stage, and the survival rate remains as low as 15%–50%. Thus, early diagnosis is pivotal to promoting survival rate and prognosis for OSCC patients. Leukoplakia, erythroplakia, oral lichen planus, and oral submucous fibrosis are potentially oral malignant disorders (OPMDs) that can transform into OSCC. According to the type of lesion, the malignant transformation rate may range from 0% to 20% in 1–30 years. Thus, clinical examination, besides oral cancer screening by reliable biomarkers, is critical in high-risk groups for early diagnosis, prognosis, and application of therapeutic approaches.
Methods: Literature review: Recent studies highlighted that body fluids such as saliva, serum, plasma, and urine can be applied for disease monitoring. The body fluids contain reliable biomarker profiles during the tumorigenesis process that demonstrate early diagnosis, recurrence, survival, the beginning stages of invasion, metastasis, and angiogenesis process, and pharmacological response to therapeutic intervention.
Results: There are many benefits of using saliva as a biofluid: easily accessible, inexpensive, noninvasive collection, safe to handle in comparison to the blood, the possibility of greater volume for assessment, and repeated sampling for monitoring many times, easy to store as it does not clot, the potential of self-collection by patient removes direct interaction with investigators, thus decreasing the risk of infections, and applicable for mass screening of large population. In this way, the saliva, known as a "mirror of the body", can reflect the physiological and pathological situation of the body. "Salivaomics" constituents of saliva that comprise proteome, transcriptome, metabolome, and microbiome profile signature. This technology allows us to detection of circulating tumor cells (CTCs) and fragments of tumor DNA in saliva for early detection of various cancers. CTCs carry on unique genomic, transcriptomic, and epigenomic signatures of tumor nature.
Conclusion: Conclusion: Body Fluid biomarkers, especially saliva, can be a reliable strategy for early diagnosis, prognosis, and therapeutic approaches in oral cancer. In addition, detecting and diagnosing malignant lesions can be considered for human immunodeficiency virus, heart disease, and autoimmune diseases.
Keywords: Oral squamous cell carcinoma,Oral cancer,Biomarkers, Body fluids,Saliva,Circulating tumor cells.