title: The detection of gastric cancer cells in intraoperative peritoneal lavage using the reverse transcription--loop-mediated isothermal amplification method.
abstract: BACKGROUND
  To detect a small number of malignant cells, we used a highly sensitive detection system that measures the expression levels of cytokeratin (CK) 19 messenger RNA by reverse transcription-loop-mediated isothermal amplification (RT-LAMP).
  
  
  METHODS
  We evaluated the clinical relevance of our novel diagnostic method with an RT-LAMP assay using CK19 as a target gene for the detection of free cancer cells in peritoneal lavage and assessed the clinical significance of the molecular diagnosis by survival analysis and frequency of recurrence, with a median follow-up period of 39 mo. We observed 52 patients with gastric cancer who underwent gastrectomy, bypass operation, and exploratory laparotomy.
  
  
  RESULTS
  Those 52 patients, who were subjected to both RT-LAMP and cytologic examination, were divided into the following three groups: (1) patients positive by cytology and RT-LAMP (CY+/LAMP+) (n = 9), (2) patients positive by LAMP and negative by cytology (CY-/LAMP+) (n = 12), and (3) patients negative by both cytology and LAMP (CY-/LAMP-) (n = 31). All patients with simultaneous peritoneal dissemination and positive cytology were positive on RT-LAMP. The results of RT-LAMP were statistically significant for recurrence by univariate analysis (P < 0.005). Cytology-positive cases had a very poor prognosis, and RT-LAMP-positive cases had a worse prognosis than RT-LAMP-negative cases.
  
  
  CONCLUSIONS
  Our findings suggest that CK19 RT-LAMP would be useful as an intraoperative diagnostic modality to detect patients with a high risk of recurrence even after clinically curative surgery, who thus require proper adjuvant therapy.
authors.affiliation: Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. Electronic address: dm06034e@cc.nagasaki-u.ac.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Yoneda
authors.affiliation: Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Taniguchi
authors.affiliation: Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Torashima
authors.affiliation: Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Seiya
authors.initials: S
authors.lastname: Susumu
authors.affiliation: Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Kanetaka
authors.affiliation: Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kuroki
authors.affiliation: Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Eguchi
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics; D002277:Carcinoma / Q000235:genetics / Q000401:mortality / Q000556:secondary*; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D053539:Keratin-19 / Q000235:genetics; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D010533:Peritoneal Lavage / Q000379:methods*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000235:genetics / Q000401:mortality / Q000556:secondary*
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D053539:Keratin-19; D012333:RNA, Messenger
keywords: Gastric cancer; Peritoneal lavage; RT–LAMP