Circulating Tumor Cells and Their Clinical Significance in Gastric Cancer

Gastric adenocarcinoma is the fourth most common type of cancers and it is the third leading cause of cancer-related death globally. Unfortunately, more than 40% of patients with gastric cancer (GC) have no response to chemotherapy. The rest resist chemotherapy, which leads to low survival and limited therapeutic options. Circulating tumor cells (CTCs) are originated from the primary tumor and are present in the blood stream. In recent years, CTCs have been discussed as a primary diagnostic marker for metastasis; therefore, it may act as a diagnostic and prognostic marker for GC. These cells have the ability of self-renewal and can replicate and grow in a manner similar to that of stem cells. To date, the CellSearch system is the only CTC diagnostic technique approved by U.S FDA. The purpose of this study was to provide a comprehensive overview of the methods for detection of CTCs as well as an insight into the clinical significance of CTCs in relation to GC and recent technical advances in identifying and isolating them.