Recent advances in gastric cancer early diagnosis

Figure 1 Possible non-invasive diagnostic biomarkers for early-stage gastric cancer. Genetic and epigenetic alterations, microRNAs, long non-coding RNAs and circular RNA, circulating tumor cells and tumor DNA represent promising candidates for the development of new non-invasive methods in early-diagnosis of gastric cancer. GC: Gastric cancer; miRNAs: MicroRNAs; lncRNAs: Long non-coding RNAs; circRNA: circular RNA; CTCs: Circulating tumor cells; cfDNAs: Cell-free circulating DNA.

Figure 2 Methylation changes in gastric cancer. Epigenetic alteration by methylation occurs in specific genes involved in various processes such as cell cycle regulation, DNA repair, cell growth/differentiation, transcriptional regulation, cell adhesion/invasion/migration, apoptosis, angiogenesis, as well as in multidrug resistance genes, and in genes associated with Epstein-Barr virus-type tumors or Helicobacter pylori positive tumors. These gene alterations are correlated with tumor size, localization, differentiation, invasion, lymph node metastasis, distant metastasis, TNM stage, and prognosis. GC: Gastric cancer.