title: Frequency of HER2/neu overexpression in adenocarcinoma of the gastrointestinal system.
abstract: OBJECTIVE
  To determine the frequency of HER2/neu protein overexpression in gastric (group A), small intestine (group B), and colorectal (group C) adenocarcinoma.
  
  
  METHODS
  A descriptive, cross-sectional study was performed on 50 cases of gastrointestinal adenocarcinoma (stomach, small intestine, and colorectal); 11 from group A, 8 from group B, and 31 from group C. The samples were grossed and processed in the pathology department, and sections were stained with HE (hematoxylin and eosin stain) for histopathological confirmation of malignancy (well-differentiated, moderately-differentiated, and poorly-differentiated). The confirmed samples were processed for immunomarker study of HER2/neu.
  
  
  RESULTS
  HER2/neu protein overexpression was found in 33 (66%) patients overall (P = 0.000). Out of 33 HER2/neu positive subjects, 23 (69.6%) were from group C, while the remaining 10 (30%) were from group A. None of the patients from group B had positive HER2/neu protein overexpression. No protein overexpression or membrane staining in < 10% tumor cells was observed in 17 (34%) patients, which were labeled as score "0" and considered negative for HER2/neu protein overexpression. Faint/weak staining (in ≥ 10% of tumors cells) were observed in 8 (16%) patients and given the "1+" score. Similarly 13 (26%) patients reported moderate staining (in ≥ 10% tumor cells) and were thus labeled as "2+", and strong staining (in ≥ 10% tumors cells), labeled as "3+", was observed in 12 (24%) patients. Out of 50 patients, 26 (52%) were suffering from grade-II malignancy, 16 (32%) from grade-I, and 8 (16%) from grade-III. There was highly significant association between tumor grades and HER2/neu protein overexpression (P = 0.0000).
  
  
  CONCLUSIONS
  HER2/neu protein is credibly overexpressed in colon and gastric adenocarcinomas in immunohistochemistry. There is significant association between grade of tumor and HER2/neu protein overexpression.
authors.affiliation: Sadaf Farzand, Tahir Siddique, Kanwal Saba, Mulazim Hussain Bukhari, Department of Pathobiology, King Edward Medical University, Lahore 54000, Pakistan.
authors.forename: Sadaf
authors.initials: S
authors.lastname: Farzand
authors.affiliation: Sadaf Farzand, Tahir Siddique, Kanwal Saba, Mulazim Hussain Bukhari, Department of Pathobiology, King Edward Medical University, Lahore 54000, Pakistan.
authors.forename: Tahir
authors.initials: T
authors.lastname: Siddique
authors.affiliation: Sadaf Farzand, Tahir Siddique, Kanwal Saba, Mulazim Hussain Bukhari, Department of Pathobiology, King Edward Medical University, Lahore 54000, Pakistan.
authors.forename: Kanwal
authors.initials: K
authors.lastname: Saba
authors.affiliation: Sadaf Farzand, Tahir Siddique, Kanwal Saba, Mulazim Hussain Bukhari, Department of Pathobiology, King Edward Medical University, Lahore 54000, Pakistan.
authors.forename: Mulazim Hussain
authors.initials: MH
authors.lastname: Bukhari
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002454:Cell Differentiation; D015179:Colorectal Neoplasms / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007414:Intestinal Neoplasms / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000378:metabolism*; D055815:Young Adult
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: Adenocarcinoma; Gastrointestinal system; HER2/neu; Immunohistochemistry