Meta-analysis of circulating tumor cells as a prognostic marker in lung cancer.
BACKGROUND
Recent studies have shown that circulating tumor cells (CTCs) play potential roles as diagnostic and prognostic biomarkers with various cancer types. The aim of this study was to comprehensively and quantitatively summarize the evidence for the use of CTCs to predict the survival outcome of lung cancer patients.


METHODS
Relevant literature was identified using Medline and EMBASE. Patients' clinical characteristics, overall survival (OS) and progression-free survival (PFS) together with CTC positive rates at different time points (before, during and after treatment) were extracted. A meta-analysis was performed to clarify the prognostic role of CTCs and the correlation between the CTC appearance and clinical characteristics.


RESULTS
A total of 12 articles containing survival outcomes and clinical characteristics and 15 articles containing only clinical characteristics were included for the global meta-analysis. The hazard ratio (HR) for OS predicted by pro-treatment CTCs was 2.61 [1.82, 3.74], while the HR for PFS was 2.37 [1.41, 3.99]. The HR for OS predicted by post-treatment CTCs was 4.19 [2.92, 6.00], while the HR for PFS was 4.97 [3.05, 8.11]. Subgroup analyses were conducted according to histological classification and detection method. Odds ratio (OR) showed the appearance of pro-treatment CTCs correlated with the lymph node status, distant metastasis, and TNM staging, while post-treatment CTCs correlated with TNM staging only.


CONCLUSIONS
Detection of CTCs in the peripheral blood indicates a poor prognosis in patients with lung cancer.
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, China.
Xue-Lei
XL
Ma
Zhi-Lan
ZL
Xiao
Lei
L
Liu
Xiao-Xiao
XX
Liu
Wen
W
Nie
Ping
P
Li
Nian-Yong
NY
Chen
Yu-Quan
YQ
Wei
D014408:Biomarkers, Tumor / Q000097:blood*; D018572:Disease-Free Survival; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000097:blood* / Q000473:pathology*; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating; D016017:Odds Ratio
D014408:Biomarkers, Tumor