title: Prognostic significance of peritoneal minimal residual disease in gastric cancer detected by reverse transcription-polymerase chain reaction.
abstract: BACKGROUND
  A sensitive method for detecting minimal residual disease in the peritoneal cavity by quantifying carcinoembryonic antigen (CEA) mRNA using real-time quantitative reverse transcription-polymerase chain reaction (RQ-RT-PCR) was developed. The clinical value of the method for predicting peritoneal recurrence in patients with gastric cancer was evaluated.
  
  
  METHODS
  A total of 195 patients with gastric cancer and 20 with asymptomatic cholecystolithiasis were included in the study. CEA mRNA expression in peritoneal washings (p-CEA mRNA) was measured by RQ-RT-PCR and normalized to glyceraldehyde-3-phosphate dehydrogenase mRNA expression. The cut-off level of p-CEA mRNA for gastric cancer was determined by examining p-CEA mRNA levels in patients with asymptomatic cholecystolithiasis.
  
  
  RESULTS
  Fifty-five (28.2 per cent) of the 195 patients were p-CEA mRNA positive. The rate of p-CEA mRNA positivity correlated significantly with clinicopathological factors. In 163 patients who underwent curative surgery, overall survival and disease-free survival were significantly poorer in p-CEA mRNA-positive patients than in p-CEA mRNA-negative patients (P < 0.001). Cox regression analysis revealed that only p-CEA mRNA was a significant independent prognostic factor (P = 0.034). Multivariate logistic regression analysis showed that p-CEA mRNA was a significant independent risk factor for peritoneal recurrence (P = 0.027).
  
  
  CONCLUSIONS
  These results suggest that p-CEA mRNA is a reliable prognostic factor and predictor of peritoneal recurrence in gastric cancer.
authors.affiliation: Department of Surgery 1, Iwate Medical University, Morioka, Fukushima, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Oyama
authors.forename: M
authors.initials: M
authors.lastname: Terashima
authors.forename: A
authors.initials: A
authors.lastname: Takagane
authors.forename: C
authors.initials: C
authors.lastname: Maesawa
mesh_terms: D002272:Carcinoembryonic Antigen / Q000032:analysis*; D018076:DNA, Complementary / Q000032:analysis; D018572:Disease-Free Survival; D006801:Humans; D018365:Neoplasm, Residual / Q000473:pathology; D010534:Peritoneal Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000556:secondary; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000473:pathology*; D014407:Tumor Cells, Cultured
chemical_list: D002272:Carcinoembryonic Antigen; D018076:DNA, Complementary; D012333:RNA, Messenger; D012334:RNA, Neoplasm