title: Prevalence of p21 immunohistochemical expression in esophageal adenocarcinoma.
abstract: BACKGROUND
  In western societies, the prevalence of adenocarcinoma of the gastroesophageal junction has increased in recent years. It is commonly accepted today that esophageal adenocarcinoma develops from a premalignant lesion: Barrett's esophagus. This type of carcinoma is hardly diagnosed at early stages, which results in significant mortality. Molecular biology studies have shown that most malignant tumors originate from the interaction between inherited characteristics and external factors, which may cause genetic changes that interfere with the control over the differentiation and growth of cells in susceptible individuals. p21 (WAF1/CIP1) has a key role in the regulation of the cell cycle, and its immunohistochemical expression has been investigated in several tumors, showing that it influences the prognosis of various neoplasms.
  
  
  OBJECTIVE
  To check the prevalence of p21 protein expression in patients with esophageal adenocarcinoma diagnosed in the last 5 years by the Group for Surgeries of the Esophagus and Stomach of "Hospital de Clínicas de Porto Alegre", RS, Brazil.
  
  
  METHODS
  The study population consisted of 42 patients with esophageal adenocarcinoma diagnosed by the Group for Surgeries of the Esophagus and Stomach between January 1998 and December 2002. The expression of p21 protein was determined by immunohistochemistry using primary antibody, p21, clone SX118, code M7202 (Dako), and assessed according to the immunoreactive scoring system.
  
  
  RESULTS
  Of 42 analyzed patients, 83.3% were male and older than 40 years. Among these, 56.2% were submitted to curative resection: total gastrectomy and transhiatal esophagogastrectomy. The remaining patients were submitted to palliative surgery or did not undergo any surgical treatment. Only five patients received adjuvant chemotherapy and radiation therapy, either alone or combined. Advanced disease (stages III and IV) was detected in 78.6% of the patients. Only nine patients were positive for p21, according to the immunoreactive scoring system.
  
  
  CONCLUSIONS
  p21 was expressed in 9 of 42 patients (21.4%) with esophageal adenocarcinoma diagnosed in the last 5 years by the Group for Surgeries of the Esophagus and Stomach of Hospital de Clínicas de Porto Alegre. In our patient population, the accumulation of p21 did not play a key role in the carcinogenesis of esophageal adenocarcinoma.
authors.affiliation: Division of General Surgery, Hospital de Clínicas, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil. javillwock@via-rs.net
authors.forename: Maitê de Mello
authors.initials: Mde M
authors.lastname: Villwock
authors.forename: Luise
authors.initials: L
authors.lastname: Meurer
authors.forename: Leandro Totti
authors.initials: LT
authors.lastname: Cavazzola
authors.forename: Richard R
authors.initials: RR
authors.lastname: Gurski
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Edelweiss
authors.forename: Carlos Cauduro
authors.initials: CC
authors.lastname: Schirmer
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000032:analysis / Q000378:metabolism*; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21