Detection of circulating tumor cells by RT-PCR significantly associated with poor prognosis in breast cancer

Circulating tumour cells predict survival in gastric cancer patients: a meta-analysis

AIM OF THE STUDY

The prognostic value of the detection of circulating tumour cells (CTCs) in gastric cancer has been studied intensely in recent years. However, the application of different technologies led to inconsistent results between the studies. Here, we performed a meta-analysis of published studies to summarise the evidence.

MATERIAL AND METHODS

Medline and ISI Web of Knowledge were searched up to March 2013 using "circulating tumor cells" and "gastric cancer" as search terms. Hazard ratio (HR) with 95% confidence intervals (CIs) for prognostic outcomes and clinical characteristics were extracted from each study. Pooled hazard ratios (HR) and odds ratios (OR) were calculated using random or fixed-effects models.

RESULTS

Twelve studies enrolling 774 patients were included. The combined HR estimate for overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS) were 1.41 (95% CI: 1.28-1.62), 2.99 (95% CI: 2.01-4.45) and 1.64 (95% CI: 1.02-2.62), respectively. Subgroup analysis concerning detection methods and sampling time showed that results of RT-PCR for the OS group and RT-PCR for the DFS group suggest a prognostic significance of CTC detection (pooled HR [95% CI]: 1.45 [1.28-1.65], I(2) = 38%, p = 0.13; 2.99 [2.01-4.45], I(2) = 0%, p = 0.32). In addition, results of the baseline CTC detection group also indicated a significant prognostic value to predict OS and DFS (pooled HR [95% CI]: 1.47 [1.19-1.82], I(2) = 38%, p = 0.14; 2.99 [2.01-4.45], I(2) = 0%, p = 0.32). We simultaneously found that the detection of CTCs correlated with pathological stage (pooled OR [95% CI]: 2.95 [1.65-5.28], I(2) = 56%, p = 0.03), lymph node status (pooled OR [95% CI]: 2.26 [1.50-3.41], I(2) = 37%, p = 0.09), the depth of invasion (pooled OR [95% CI]: 3.21 [1.38-7.43], I(2) = 72%, p = 0.002), and distant metastasis (pooled OR [95% CI]: 2.68 [1.25-5.73], I(2) = 43%, p = 0.15).

CONCLUSIONS

Detection of CTCs is associated with poorer prognosis in gastric cancer patients.

Carboxybetaine methacrylate-modified nylon surface for circulating tumor cell capture

Conventional in vitro circulating tumor cell (CTC) detection methods are always limited by blood sample volume because of the requirement of a large amount of blood. The aim of this study was to overcome the limitation by designing and making an in vivo CTC capture device. In this study, we designed and prepared a kind of proper material to serve the purpose of intervention. A method employing 3-aminopropyltriethoxysilane (γ-APS) as the coupling reagent to graft carboxybetaine methacrylate (CBMA) and to immobilize an anti-epithelial cell adhesion molecular (EpCAM) antibody on Nylon was developed. The results of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy proved the successful graft of γ-APS and CBMA to Nylon. Furthermore, the predicted improvement in the biocompatibilities of our modified Nylon was confirmed by water contact angle measurement, bovine serum albumin adhesion, platelet adhesion, plasma recalcification time determination, and cytotoxicity tests. The tumor cells adhesion experiment revealed that Nylon with the antibody immobilized on it had an affinity for EpCAM positive tumor cells higher than that of pristine Nylon. Additionally, the capture ability of the CTCs was demonstrated in a nude mouse tumor model using the interventional device made of the modified Nylon wire. The positive results suggest that CBMA-grafted and anti-EpCAM antibody-immobilized Nylon is a promising new material for in vivo CTC capture devices.

Meta-analysis of the prognostic value of circulating tumor cells in breast cancer

PURPOSE

The prognostic value of circulating tumor cells (CTC) detected in breast cancer patients is currently under debate. Different time points of blood collections and various CTC assays have been used in the past decades. Here, we conducted the first comprehensive meta-analysis of published literature on the prognostic relevance of CTC, including patients with early and advanced disease.

EXPERIMENTAL DESIGN

A comprehensive search for articles published between January 1990 and January 2012 was conducted; reviews of each study were conducted and data were extracted. The main outcomes analyzed were overall survival (OS) and disease-free survival (DFS) in early-stage breast cancer patients, as well as progression-free survival (PFS) and OS in metastatic breast cancer patients. Pooled hazard ratio (HR) and 95% confidence intervals (CIs) were calculated using the random and the fixed-effects models. Subgroup and sensitivity analyses were also conducted.

RESULTS

Forty-nine eligible studies enrolling 6,825 patients were identified. The presence of CTC was significantly associated with shorter survival in the total population. The prognostic value of CTC was significant in both early (DFS: HR, 2.86; 95% CI, 2.19-3.75; OS: HR, 2.78; 95% CI, 2.22-3.48) and metastatic breast cancer (PFS: HR, 1.78; 95% CI, 1.52-2.09; OS: HR, 2.33; 95% CI, 2.09-2.60). Further subgroup analyses showed that our results were stable irrespective of the CTC detection method and time point of blood withdrawal.

CONCLUSION

Our present meta-analysis indicates that the detection of CTC is a stable prognosticator in patients with early-stage and metastatic breast cancer. Further studies are required to explore the clinical utility of CTC in breast cancer.