Frequency of HER2/neu over expression in adenocarcinoma of the gastrointestinal system, a Study of 70 cases

Authors : Mansi Mukesh Thacker, Sneha Chiplonkar

DOI : 10.18231/j.jdpo.2019.057

Volume : 4

Issue : 4

Year : 2019

Page No : 272-277

Aim: To study the frequency of HER2/neu overexpression in esophageal, gastric, small intestine and
colorectal adenocarcinomas, to study the association of HER2/ neu overexpression with histopathological
differentiation of esophagus, stomach, small intestine and colorectal adenocarcinomas and identifying its
significance.
Materials and Methods: Cross sectional study was performed on 70 cases which include resected
specimens of stomach, small intestine and colorectal adenocarcinoma and biopsies of esophagus and these
organs. The samples were divided into Group A (Esophagus and stomach) and Group B (Small intestine
and colorectal). The samples were grossed and processed in the pathology department, and sections were
stained with hematoxylin and eosin stain for histopathological confirmation of malignancy and graded
as well-differentiated (gradeI), moderately-differentiated (grade II) and poorly-differentiated (gradeIII )
adenocarcinomas. The confirmed samples were processed for immunomarker study of HER2/ neu.
Results: Over expression of HER2/ neu was found in 17(24.3 %) patients overall. Out of 17 HER2/
neu positive cases, 4(26.7%) were from group a, while 13(23.6%) were from group b. No staining or
membrane staining in < 10> score “0” and considered negative for HER2/ neu overexpression. Faint/barely perceptible membranous
staining in 10% of tumors cells were observed in 5 (7.1 %) patie nts, which were labeled as score
“1” and considered negative. Weak to moderate complete, basolateral or lateral membranous staining in
10% tumor cells were observed in 2(2.9%) patients, which were labeled as score “2” and considered
equivocal. Strong complete, basolateral or lateral membranous staining in 10% of tumors cells were
observed in 17(24.3%) patients, which were labeled as score “3” and considered positive. Out of 70
patients, 37(52.9%) were suffering from grade-II malignancy, 17 (24.3 %) from grade- I and 16 (22.8%)
from grade-III. According to histological grades, frequency of HER2/neu over expression was 11.8% in
well differentiated adenocarcinoma (grade I), 29.7% in moderately differentiated adenocarcinoma (grade
II) and 25% in poorly differentiated adenocarcinoma (grade III). There was no statistical significance of
HER2/neu expression and grades of tumor.
Conclusion: HER2/neu is over expressed in adenocarcinoma of gastroesophageal junction and colorectal
adenocarcinoma. There is no statistical significance of HER2/neu expression and grades of tumor.

Keywords: HER2/neu, Immunohistochemistry, Adenocarcinoma, Gastrointestinal system.


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