Biomarkers in ovarian cancer and saliva: An update

Asymptomatic nature at the initial stage and heterogeneity makes ovarian cancer a “silent killer” which is being considered as most lethal gynecological cancer by acquiring the fifth leading cause of cancer-related deaths in women. Detection of ovarian cancer frequently requires painful invasive procedures such as multiple biopsies and blood tests which results in an undue stress and discomforts in patient. Recently, saliva is being opted as an alternative source for biomarker discovery due to procedure being non-invasive collection method cost-effectiveness, ease of sample collection, and handling. Saliva, a multiconstituent oral fluid secretion from the major and minor salivary glands enriched with proteins, DNAs, RNAs, and metabolites, behaves as a “mirror of the body.” Salivary diagnostics has become booming field with the development of new and advanced technologies accompanying with proteomics, RNA sequencing, liquid biopsy, and point-of-care (POC) diagnostics. Reliable and reproducible biomarkers identified through advanced salivaomics techniques such as proteomics, transcriptomics, genomics, and metabolomics for oral and systemic diseases including cancers can serve as a diagnostic and monitoring tool. Scientific communities are engaged in developing new technologies for the identification and validation of an extensive range of salivary biomarkers that will provide clinical and scientific credibility for saliva. This review provides a comprehensive update about the significant salivary biomarkers identified by the omics method that can be used for the early detection of ovarian cancer. In coming years, salivaomics may become a very important tool for early detection of ovarian cancer and salivary biomarkers may translate into improvement of treatment outcome and increased survival rate.