title: Evaluation of plakophilin-3 mRNA as a biomarker for detection of circulating tumor cells in gastrointestinal cancer patients.
abstract: BACKGROUND
  This study aims to assess Plakophilin-3 (PKP3) as a surrogate biomarker of circulating tumor cells in patients with gastrointestinal cancer.
  
  
  METHODS
  The primary aim is to estimate the diagnostic accuracy of PKP3 real-time reverse transcriptase-PCR in blood. Receiver operating characteristic curves were constructed. Correlations between the blood PKP3 levels and the clinicopathologic features of the study subjects were analyzed. Logistic regression was used to predict outcomes based on PKP3.
  
  
  RESULTS
  Sixty-four patients with gastrointestinal cancer and 23 controls were included. The mean relative PKP3 mRNA expression was 48.45 in cancer patients and 2.8 in controls (P < 0.0001). Comparing the PKP3 levels in patients and controls, the area under the curve was 0.852 (95% confidence interval, 0.76-0.94; P < 0.0001) in receiver operating characteristic analysis. A higher blood level of PKP3 mRNA was associated with a more advanced stage (P = 0.025), pT(3-4) tumors (P = 0.028), metastasis (P = 0.021), and residual (R2) disease (P = 0.037). Higher PKP3 mRNA was associated with the risk of cancer progression and death (odds ratio, 3.875; 95% confidence interval, 1.781-8.430; P = 0.001).
  
  
  CONCLUSIONS
  Increased PKP3 mRNA was detected in the blood of gastrointestinal cancer patients. Significant correlations were found with advanced stage, pT(3-4), metastatic disease, and the residual disease status. PKP3 mRNA in blood was associated with the risk of cancer progression and death.
  
  
  CONCLUSIONS
  PKP3 mRNA can be used as a marker of subclinical disease in gastrointestinal cancer and thus holds potential clinical relevance as a predictor for disease outcome.
authors.affiliation: Medical Oncology, University Hospital, La Coruña, Spain. manuel.valladares.ayerbes@sergas.es
authors.forename: Manuel
authors.initials: M
authors.lastname: Valladares-Ayerbes
authors.forename: Silvia
authors.initials: S
authors.lastname: Díaz-Prado
authors.forename: Margarita
authors.initials: M
authors.lastname: Reboredo
authors.forename: Vanessa
authors.initials: V
authors.lastname: Medina
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Lorenzo-Patiño
authors.forename: Pilar
authors.initials: P
authors.lastname: Iglesias-Díaz
authors.forename: Mar
authors.initials: M
authors.lastname: Haz
authors.forename: Sonia
authors.initials: S
authors.lastname: Pértega
authors.forename: Isabel
authors.initials: I
authors.lastname: Santamarina
authors.forename: Moises
authors.initials: M
authors.lastname: Blanco
authors.forename: Maria
authors.initials: M
authors.lastname: Quindós-Varela
authors.forename: Angélica
authors.initials: A
authors.lastname: Figueroa
authors.forename: Luis M
authors.initials: LM
authors.lastname: Antón-Aparicio
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics*; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000097:blood* / Q000235:genetics / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000378:metabolism* / Q000473:pathology; D051191:Plakophilins / Q000097:blood / Q000235:genetics*; D011237:Predictive Value of Tests; D012333:RNA, Messenger / Q000097:blood* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; C495339:PKP3 protein, human; D051191:Plakophilins; D012333:RNA, Messenger