title: p53 immunohistochemical expression in Barrett's esophagus before and after endoscopic ablation by argon plasma coagulation.
abstract: OBJECTIVE
  Few studies have evaluated p53 accumulation in the squamous mucosa contiguous (SMC) to Barrett's esophagus (BE) and in the new squamous epithelium after endoscopic ablation. We evaluated the p53 expression in BE, in the SMC, and in the new squamous mucosa generated after ablation by argon plasma coagulation (APC).
  
  
  METHODS
  Endoscopic biopsy specimens from 37 BE patients, before and after ablation by APC, were analyzed. The p53 immunostaining criterion used was the staining of at least half of the nuclei.
  
  
  RESULTS
  p53 was detected in BE in 5 (13.5%) cases. In all these cases, SMC was p53(+). In addition, SMC was p53(-) in all cases of p53(-) BE (p <0.001). In the 5 cases with p53(+) BE and SMC, the new squamous mucosa continued to be p53(+). However, in the 32 cases with p53(-) SMC, the new squamous mucosa was also p53(-) (p <0.001). No case with p53(+) SMC turned out to be p53(-) after ablation. Similarly, no case with p53(-) BE and SMC before eradication became p53(+) after ablation (p < 0.001).
  
  
  CONCLUSIONS
  p53 was highly prevalent in the contiguous squamous mucosa when it is present in BE. After ablation, none of the cases lost p53 expression, and none of the negative cases turned out to be positive.
authors.affiliation: Department of Pathology and Gastroenterology of the Porto Alegre School of Medical Sciences/Santa Casa Hospital, Porto Alegre, Brazil. cevele@terra.com.br
authors.forename: César Vivian
authors.initials: CV
authors.lastname: Lopes
authors.forename: Júlio
authors.initials: J
authors.lastname: Pereira-Lima
authors.forename: Antônio Atalíbio
authors.initials: AA
authors.lastname: Hartmann
mesh_terms: D000911:Antibodies, Monoclonal; D001471:Barrett Esophagus / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D015415:Biomarkers; D001706:Biopsy; D018450:Disease Progression; D004945:Esophagoscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D017075:Laser Coagulation / Q000379:methods*; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D011184:Postoperative Period; D011300:Preoperative Care; D015203:Reproducibility of Results; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D016159:Tumor Suppressor Protein p53