Clinical significance of circulating tumor cells in gastric cancer patients

Abstract

Circulating tumor cells (CTCs) are rare cancer cells released from tumors into the blood stream that are thought to have a key role in cancer metastasis. Investigation of CTCs is an exciting area of research but remains in its infancy, and the presence of CTCs has been associated with worse prognosis in several major cancer types. Gastric cancer (GC) is a highly lethal malignancy and a serious public health concern in East Asia especially in China. There is an urgent need for identifying new, better prognostic markers to enhance diagnosis and prognosis, facilitate drug development, and to improve the treatment of gastric cancer patients. There are considerable interests in gastric CTCs given their potential use as gastric cancer biomarkers. This review highlights recent advances in studies of gastric CTCs, including the isolation and biological molecular characteristics of gastric CTCs, and their clinical significance.

Circulating tumour cells and DNA as liquid biopsies in gastrointestinal cancer

“…CTCs and ctDNA may be of prognostic value in several gastrointestinal cancers, where the biggest impact may be their detection before therapeutic intervention. As a cancer (or minimal residual disease) evolves with time and treatment, selection pressure from surgery, chemotherapy or radiotherapy, or tumoricidal immunity could stimulate the expansion of tumour subclones ( Fig .…”

Current progress in the clinical use of circulating tumor cells as prognostic biomarkers

“…Within the CTC population, gastric cancer CTCs with stem-like properties are considered to play a particular role in metastasis, and CD44-positive CTCs in patients with gastric cancer have been found to be predictive of both metastasis and disease recurrence. 61 More specific biomarkers, such as EpCAM, which is known to be predictive of peritoneal metastasis in patients with gastric cancer, 62 have potential as targets in liquid biopsies of CTCs for gastric cancer prognosis. The use of microemboli in addition to CTCs, and especially close examination of their expression of specific proteins, also recently has been shown to be promising for gastric cancer prognosis.…”

“…CTC count has been reported to be predictive of metastasis in patients with gastric cancer, which is a particularly aggressive cancer that is common in Asia, Eastern Europe, and Central and South America. Within the CTC population, gastric cancer CTCs with stem‐like properties are considered to play a particular role in metastasis, and CD44‐positive CTCs in patients with gastric cancer have been found to be predictive of both metastasis and disease recurrence . More specific biomarkers, such as EpCAM, which is known to be predictive of peritoneal metastasis in patients with gastric cancer, have potential as targets in liquid biopsies of CTCs for gastric cancer prognosis.…”

Tumor-specific genetic aberrations in cell-free DNA of gastroesophageal cancer patients

“…In Europe, perioperative combination chemotherapy or pre-operative concomitant chemoradiation therapy is recommended in patients with resectable disease [2][3][4], but in Asia and US post-operative chemotherapy or chemoradiation is often used. In patients with locally advanced or disseminated GEC, combination chemotherapy prolongs median overall survival from a few months to [10][11][12] months [5,6]. The number of available targeted therapies is limited in GEC [7,8] and several clinical trials of targeted therapies are currently ongoing, but many drugs have failed, possibly to some extent due to poor patient selection [9].…”

“…Blood samples from cancer patients may contain tumor cells and subcellular components from the tumor. Circulating tumor cells [10], microvesicles such as exosomes [11], and cell-free, circulating tumor DNA [12] and RNA (predominantly microRNAs) [13] have all been suggested as potential biomarkers. The use of these so-called 'liquid biopsies' has been investigated extensively during the last decade [12,14,15], facilitated by the improvement of molecular genetic methods.…”