Sebina Asmi A.T.1, Suma Madathiveetil2 1,
BACKGROUND
Human epidermal growth factor receptor-2 HER2 / neu, is a trans membrane
tyrosine kinase receptor of epidermal growth factor receptor (EGFR) family and is
involved in the pathogenesis of urinary bladder cancer. In this study we attempted
to evaluate the HER2 / neu expression in urothelial carcinoma of bladder and its
association with tumour grading.
METHODS
This was a cross sectional study with a sample size of 75. Routine 4 micrometre
thick sections of formalin fixed paraffin embedded tissue blocks stained with
haematoxylin & eosin were reviewed. Tumour grade was determined by using the
World Health Organization (WHO) / International Society of Urological Pathologist
criteria (ISUP). Immunohistochemistry was done by using HER2 / neu monoclonal
antibody and its expression were observed. The membrane staining intensity and
pattern were studied and scored.
RESULTS
In our study 75 cases of urothelial carcinoma were studied, of which 49 cases
were papillary urothelial carcinoma low grade, 26 cases were papillary urothelial
carcinoma high grade. Among these, 19 cases were infiltrating urothelial
carcinoma. HER2 / neu positivity were observed in 27 (36 %) cases and
overexpression in 8 (10 %) cases. Low grade urothelial carcinoma showed HER2
/ neu positivity in 11 (22 %) cases and overexpression in 1 (2 %) case. High grade
urothelial carcinoma showed HER2 / neu positivity in 16 (64 %) cases, among
which 7 (28 %) cases showed overexpression. HER2 / neu positivity was seen in
13 (68 %) cases of infiltrating urothelial carcinoma with 4 (21 %) cases showing
overexpression. A statistically significant difference in HER2 / neu expression was
noted in high grade and invasive urothelial carcinoma compared to low grade and
non-invasive urothelial carcinoma.
CONCLUSIONS
Urothelial carcinomas show overexpression of HER2 / neu and this over expression
increases with increasing grade of tumour and muscle invasiveness.
