title: Circulating Tumor Cells as an Independent Predictor of Survival in Advanced Gastric Cancer.
abstract: BACKGROUND
  When the indication for surgery of highly advanced gastric cancer is considered, careful selection of the patients is important. In addition to tumor-node-metastasis factors and peritoneal lavage cytology (CY), which are important predictors of prognosis, detection of circulating tumor cells (CTCs) could be another potential marker.
  
  
  METHODS
  This study prospectively evaluated CTCs using a semi-automated immunomagnetic separation system (CellSearch) for 136 patients with advanced gastric cancer to determine the frequency of CTC positivity. For 123 patients who also had their CY evaluated, the significance of both CTC and CY, was investigated as a potential biomarker to predict progression-free survival (PFS) or to monitor the therapeutic effect.
  
  
  RESULTS
  In 25 patients (18.4 %), CTCs were positive. Positive CTC counts were more common for tumors with diffuse histologic type and distant metastasis. The PFS of CTC-positive patients was significantly shorter than that of CTC-negative patients (hazard ratio 2.03; P = 0.016). A multivariate analysis of 123 patients showed that CTC and CY as well as performance status and macroscopic distant metastasis were independent factors for PFS. When both CTC and CY were converted to negative values by therapeutic interventions, long-term PFS was achieved.
  
  
  CONCLUSIONS
  Detection of CTCs was an independent predictor of a shorter PFS in advanced gastric cancer. For selecting patients who require intensive treatment, CTCs could be a valuable biomarker. The combined status of CTC and CY would be useful in selecting patients for radical surgery. Further investigation with a larger number of patients is necessary to establish the importance of CTCs.
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine Kyoto University, Kyoto, Japan. hokabe@kuhp.kyoto-u.ac.jp.
authors.forename: H
authors.initials: H
authors.lastname: Okabe
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine Kyoto University, Kyoto, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tsunoda
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine Kyoto University, Kyoto, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hosogi
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine Kyoto University, Kyoto, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Hisamori
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine Kyoto University, Kyoto, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Tanaka
authors.affiliation: Division of Breast Surgery, Department of Surgery, Graduate School of Medicine Kyoto University, Kyoto, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine Kyoto University, Kyoto, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000556:secondary / Q000628:therapy; D000368:Aged; D001202:Ascitic Fluid / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000097:blood; D002452:Cell Count; D018572:Disease-Free Survival; D005260:Female; D005743:Gastrectomy; D006801:Humans; D018189:Immunomagnetic Separation; D060828:Induction Chemotherapy; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating; D011446:Prospective Studies; D012372:ROC Curve; D066066:Response Evaluation Criteria in Solid Tumors; D013274:Stomach Neoplasms / Q000097:blood* / Q000473:pathology / Q000628:therapy; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor