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

Abstract

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 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 histologic