title: Meta-analysis of the prognostic value of circulating tumor cells detected with the CellSearch System in colorectal cancer.
abstract: BACKGROUND
  The prognostic value of circulating tumor cells (CTCs) detected with the CellSearch System in patients with colorectal cancer (CRC) is controversial. The aim of our meta-analysis was to evaluate whether the detection of CTCs in the peripheral blood with the standardized CellSearch System has prognostic utility for patients with CRC.
  
  
  METHODS
  The PubMed, Science Citation Index, Cochrane Database, Embase, and the references in relevant studies were systematically searched (up to December, 2014). No search restrictions were imposed. Our meta-analysis was performed in Stata software, version 12.0 (2011) (Stata Corp, College Station, TX, USA), with the odds ratio (OR), risk ratio (RR), hazard ratio (HR), and 95% confidence interval (95% CI) as the effect measures. Subgroup and sensitivity analyses were also conducted.
  
  
  RESULTS
  Eleven studies containing 1847 patients with CRC were analyzed. There was a significantly higher incidence of CTCs in the metastasis-positive group than in the metastasis-negative group (OR = 4.06, 95% CI [1.74, 9.50], P < 0.01, I(2) = 0%). For hepatic metastasis, a type of metastasis, a higher incidence of CTCs was observed in the hepatic-metastasis-positive group than in the -negative group (OR = 2.61, 95% CI [1.73, 3.96], P < 0.01, I(2) = 0%). The presence of CTCs was significantly related to overall survival (HR = 2.00, 95% CI [1.49, 2.69], P < 0.01, I(2) = 67.1%) and progression-free survival (HR = 1.80, 95% CI [1.52, 2.13], P < 0.01, I(2) = 43.9%) of patients with CRC, regardless of the sampling time. The response rate for the CTC(+) groups was significantly lower than that for the CTC(-) groups at baseline and during treatment (baseline: 33% versus 39%, RR = 0.79, 95% CI [0.63, 0.99], P = 0.04, I(2) = 7.0%; during treatment: 17% versus 46%, RR = 0.41, 95% CI [0.22, 0.77], P = 0.01, I(2) = 0.0%;).
  
  
  CONCLUSIONS
  Our meta-analysis indicates that the detection of CTCs in the peripheral blood with the CellSearch System has prognostic utility for patients with CRC.
authors.affiliation: Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, 155 North Nanjing Street, Heping District, 110001, Shenyang City, People's Republic of China. qq_347310502@126.com.
authors.forename: Xuanzhang
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, 155 North Nanjing Street, Heping District, 110001, Shenyang City, People's Republic of China. gaokaji16@163.com.
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.affiliation: Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, 155 North Nanjing Street, Heping District, 110001, Shenyang City, People's Republic of China. songyongxi840309@126.com.
authors.forename: Yongxi
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, 155 North Nanjing Street, Heping District, 110001, Shenyang City, People's Republic of China. sun2003999@163.com.
authors.forename: Jingxu
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, 155 North Nanjing Street, Heping District, 110001, Shenyang City, People's Republic of China. chenxiaowan516@gmail.com.
authors.forename: Xiaowan
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, 155 North Nanjing Street, Heping District, 110001, Shenyang City, People's Republic of China. zjh900521@163.com.
authors.forename: Junhua
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, 155 North Nanjing Street, Heping District, 110001, Shenyang City, People's Republic of China. xuhuimian@126.com.
authors.forename: Huimian
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, 155 North Nanjing Street, Heping District, 110001, Shenyang City, People's Republic of China. josieon826@sina.cn.
authors.forename: Zhenning
authors.initials: Z
authors.lastname: Wang
mesh_terms: D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D009362:Neoplasm Metastasis; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D016017:Odds Ratio; D011379:Prognosis; D016016:Proportional Hazards Models; D017594:Publication Bias; D016019:Survival Analysis; D016896:Treatment Outcome