2.2　Role of Biomarker in Tumor

Advancement in cancer biomarker research parallel the development of technologies.In recent years, great strides in genomic and proteomic analytical methods have uncovered highly complex signaling networks that contribute to disease onset and progression.In turn, the diverse pathophysiology of cancers and the heterogeneous nature of tumors illustrate the compound effect that genetic and protein alterations have on oncogenic signaling.Most cancer biomarker studies examine individual genetic variables, transcriptome alterations, and impaired protein function as distinct risk and prognostic factors.These single streamline approaches to biomarker discovery can be attributed to the available analytical methods, which assess genomic (DNA), transcriptome(RNA) or protein composition separately.The introduction of next-generation sequencing (NGS)has tremendously improved the sensitivity and high throughput capabilities of genomic techniques,leading to a disproportionate increase in the identification of genetic variables in cancer.NGS allows detection and quantification of low frequency genomic alterations in biopsy samples,generating large datasets of variants observed in cancer populations.These genomic studies further emphasize the high degree of heterogeneity reported within tumors and the compound effect of multiple mutations on disease onset and progression.Despite abundance of genomic data,biomarker discovery is limited by the ability to distinguish driver mutations from variables not contributing to cancer pathophysiology.Integrating genomic data and proteomic analysis,proteogenomics, can generate a comprehensive view of cell signaling that is capable of identifying abnormalities to serve as risk, diagnostic or prognostic markers as well as therapeutic targets [2-4].(https://www.daowen.com)