Targeted therapies are becoming more common and genetic tumor profiling is becoming more precise and affordable. The aim of the present review was to demonstrate the importance of molecular analyses in tumors, summarize the current situation, provide an outlook on how to improve diagnosis to facilitate individualized therapy, including the use of specific methodologies for tumor marker analysis to improve patient treatment. Most predicted metabolomic and proteomic biomarkers have not progressed from the laboratory to clinical trials, as most of the trials were stopped at the initial stage of biomarker identification. The use of liquid biopsies as a clinical tool improves cancer screening, diagnosis and prognosis; furthermore, is able to improve the classification of more diverse disease entities, assess therapy response and identify treatment-resistant clones, allowing for more stringent patient monitoring. Based on specific clinical populations and the unique molecular features of a cancer, the identification of a suitable targeted therapy may be accomplished. The present review provides insight into cancer genomic testing in the clinical setting and the available methods, supporting the prioritization of molecular therapeutic tumor targeting. Contents1. Introduction 2. Translating complex biomarkers into molecular diagnostics 3. Molecular markers for the selection of cancer therapy 4. Liquid biopsy and personalized therapy 5. Precision medicine trials and treatment algorithm 6. Conclusion

A recent advance next generation sequencing (NGS) technology has enabled the identification of potential disease-based biomarkers in saliva or epithelial cells. There has been no effective oral squamous cell carcinoma (OSCC) biomarker or well-organised molecular detection method until now, which make early diagnosis difficult, if not impossible. This chapter summarises advances in cancer research using NGS and proposes biomarkers for screening and diagnosis of OSCC using the NGS technique. As part of our review, we covered four categories: OSCC and salivary biomarkers, Uses of NGS and definitions, present biomarkers in NGS, and Candidate salivary biomarkers for OSCC using NGS.