Prognostic Value of Circulating Tumor Cells in Ovarian Cancer: A Meta-Analysis

Abstract

BackgroundThe prognostic value of circulating tumor cells (CTCs) in ovarian cancer has been investigated in previous studies, but the results are controversial. Therefore we performed a meta-analysis to systematically review these data and evaluate the value of CTCs in ovarian cancer.Materials and MethodsA literary search for relevant studies was performed on Embase, Medline and Web of Science databases. Then pooled hazard ratios (HRs) for survival with 95% confidence intervals (CIs), subgroup analyses, sensitivity analyses, meta-regression analyses and publication bias were conducted.ResultsThis meta-analysis is based on 11 publications and comprises a total of 1129 patients. The prognostic value of the CTC status was significant in overall survival (OS) (HR, 1.61;95% CI,1.22–2.13) and progression-free survival (PFS)/disease-free survival (DFS) (HR, 1.44; 95%CI, 1.18–1.75). Furthermore, subgroup analysis revealed that the value of CTC status in OS was significant in "RT-PCR" subgroup (HR, 2.02; 95% CI, 1.34–3.03), whereas it was not significant in "CellSearch" subgroup (HR, 1.15; 95% CI 0.45–2.92) and "other ICC" subgroup (HR, 1.09; 95% CI 0.62–1.90). The presence of CTC was also associated with an increased CA-125 (OR, 4.07; 95%CI, 1.87–8.85).ConclusionOur study demonstrates that CTC status is associated with OS and PFS/DFS in ovarian cancer.

Liquid biopsy in ovarian cancer: recent advances on circulating tumor cells and circulating tumor DNA

“…Recent studies attempted to show the prognostic and predictive value of CTCs as tumor biomarkers in patients with ovarian cancer [16], and three meta-analyses report these associations using the appropriate methods for the results statistical analysis [17][18][19]. Different detection methods were used, mainly based on immunocytochemistry (microscopic detection or the FDA-approved CellSearch ® system), RT-PCR (AdnaTest, QIAGEN, Hilden, Germany), and RT-qPCR for the quantification of CTCs levels [20,21].…”

Prognostic Value of Circulating Tumour Cells detected with the CellSearch System in Esophageal Cancer Patients: A Systematic Review and Meta-Analysis

“…As described in the "seed and soil" theory (29), CTCs are regarded as critical factors for tumours metastasis (30). As demonstrated in many studies, high CTCs in peripheral blood was associated with the poor survival in many solid tumours, such as breast cancer (31), bladder cancer(32), ovarian cancer and gastric cancer (33,34). In addition, due to its benefits of time and cost saving, easy operation and higher specificity and reproducibility, CTC detection from PB can be regarded as an effective evaluation tool for monitoring and assessing treatment effects in EC patients.…”

Novel technologies in the treatment and monitoring of advanced and relapsed epithelial ovarian cancer

“…Downstream PCR profiling of gene expression panels from such populations could be contaminated with leucocyte profiles [54,55], therefore careful designing of assays to exclude leucocyte contamination is required. Conflicting evidence examining the predictive value of CTCs in ovarian cancer exists; Liu et al concluded that CTCs isolated using the CellSearch™ system did not significantly correlate with patient outcome or clinical characteristics [46], however a recent meta-analysis from Zhou et al using data from eleven publications showed that CTC status was associated with overall survival (OS) and progression free survival (PFS) in ovarian cancer, with subgroup analysis showing that CTC status for OS was significant in the “RT-PCR” subgrouping and not in the “CellSearch” subgrouping [56]. Nonetheless, significant progress and standardization of methodologies is essential to improve the isolation and profiling of CTCs, to develop this type of “liquid biopsy” for the real-time non-invasive monitoring of ovarian cancer.…”