title: Clinical significance of carcinoembryonic antigen expression of acellular mucin pools after preoperative chemoradiotherapy of rectal carcinoma.
abstract: BACKGROUND
  Although several studies have shown that the presence of acellular mucin pools in surgical specimens with rectal carcinomas examined after preoperative chemoradiotherapy indicated complete response to therapy, the proper meaning of these pools has yet to be elucidated. The aims of this study were to analyze the immunoprofile of acellular mucin pools and to review the relevant literature.
  
  
  METHODS
  In 30 consecutive rectal cancers that were preoperatively treated with chemoradiotherapy, the clinicopathologic features were correlated with the immunoexpression of AE1/AE3 keratin and carcinoembryonic antigen (CEA).
  
  
  RESULTS
  Acellular mucin pools were present in all the cases, independently by their preoperative histological aspect. In remnant tumors (n=20), they were present at the invasion front and were marked by CEA. In cases without remnant tumor cells (n=10), they also displayed CEA positivity. In 2 of the 10 cases, isolated tumor cells were identified after multilevel sectioning of paraffin-embedded blocks.
  
  
  CONCLUSIONS
  The presence of acellular mucin pools in surgical specimens of rectal cancers cannot be interpreted as an indicator of complete response to radiotherapy if at least 10 multilevel sections are performed in at least three tumor blocks per case, and CEA negativity is not proved.
authors.affiliation: 1 Department of Pathology, University of Medicine and Pharmacy of Tirgu-Mures , Tirgu-Mures, Romania .
authors.forename: Simona
authors.initials: S
authors.lastname: Gurzu
authors.forename: Tivadar
authors.initials: T
authors.lastname: Bara
authors.forename: Tivadar
authors.initials: T
authors.lastname: Bara
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Kadar
authors.forename: Calin
authors.initials: C
authors.lastname: Molnar
authors.forename: Attila
authors.initials: A
authors.lastname: Kovecsi
authors.forename: Ioan
authors.initials: I
authors.lastname: Jung
mesh_terms: D000368:Aged; D002272:Carcinoembryonic Antigen / Q000378:metabolism*; D002277:Carcinoma / Q000188:drug therapy / Q000378:metabolism*; D059248:Chemoradiotherapy / Q000379:methods; D005260:Female; D006801:Humans; D007633:Keratins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000378:metabolism*; D057234:Preoperative Period; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000532:radiotherapy
chemical_list: D002272:Carcinoembryonic Antigen; D009077:Mucins; D007633:Keratins
keywords: acellular mucin pool; carcinoembryonic antigen; radiotherapy; rectal carcinoma