Circulating endothelial progenitor cell: a promising biomarker in clinical oncology

Abstract

Human cancers are endowed with sustained vascularization capability, and their growth, invasion, and metastasis are vascularization dependent. Recently, accumulated body of evidence suggests that endothelial progenitor cells (EPCs) can support vasculogenesis and induce angiogenesis through paracrine mechanisms. In addition, numerous clinical studies have revealed the increase in the number of EPCs in the peripheral blood of cancer patients and demonstrated the correlation of circulating EPCs (CEPCs) with the clinical outcomes. This review highlights current enrichment procedures and methods for the detection of CEPCs and different biomarkers to identify CEPCs as well as the functions of EPCs in tumor vascularization. Furthermore, we systematically review available studies on the clinical relevance of CEPCs in cancer patients to explore the potential diagnostic and prognostic values of CEPCs. Although several contrasting results exist, CEPCs can conceivably serve as a promising biomarker for the early diagnosis, prognosis prediction, and treatment response indication in the future. Additionally, further well-designed clinical studies with larger sample size and unique, specific enumeration procedures are warranted to achieve further insight into the clinical implications of CEPCs.

Flow cytometric analysis of circulating endothelial cells and endothelial progenitors for clinical purposes in oncology: A critical evaluation

“…These aspects, together with the heterogeneity of the patients series in the various studies, limit their potential to guide therapeutic strategies in clinical practice (69). In spite of these shortfalls, steps forward in the definition of the potential utility of CECs and EPCs for clinical purposes have been achieved, although reliable quantification of these cells is a work in progress and the interpretation of results must be made cautiously (35,10,70,71). In order to validate future reports that indicate, within well-designed trials, a true clinical value for both CECs and EPCs, unambiguous phenotypic definition of these cells together with careful inter-laboratory standardization of the quantitative techniques of analysis, including FCM, are mandatory.…”

Residential Proximity to Major Roadways Is Associated With Increased Levels of AC133 + Circulating Angiogenic Cells

“…Several clinical studies have shown the levels of these cells are chronically elevated in cancer patients and higher levels of these cells correlate with angiogenesis, metastases, and reduced patient survival. 48, 49 While all known cases of cancer were excluded from our analysis, chronically elevated levels of angiogenic cells in the blood of individuals living next to major roadways could be a symptom of incipient tumors, inflammation or tissue hypoxia or ongoing vascular injury; conditions that lead to a persistent increase in the circulating levels of angiogenic cells, especially when the insult is mild and does not overwhelm mobilization. We found that in individuals living <50m of a major roadway the levels of these cells were 48-65% higher than those living >50m from a major roadway.…”

Nintedanib for Advanced Epithelial Ovarian Cancer: A Change of Perspective? Summary of Evidence from a Systematic Review

“…Furthermore, the decrease in sVEGFR2 showed an inverse linear correlation with the trough plasma levels of Nintedanib (r = -0.46). Circulating CD117-positive bone marrow derivate endothelial progenitors have been reported to contribute to tumor angiogenesis [38]. In the same study, a subset of these cells (CD45 dim CD34+CD117+) was measured in the whole blood of 15 patients after Nintedanib administration.…”