Keratin 17 Immunohisto chemical Expression and Prognostic Value in Bladder Urothelial Carcinoma

Abstract
Background: Bladder cancer is the 2 nd most common site
of cancer in Egyptian males (12.7%), compared to other
countries, the incidence and mortality rates are high. The ratio
of Squamous Cell Carcinoma (SCC) & Urothelial Carcinoma
(UC) types showed a shift towards UC. Keratin 17 (K17) is
an oncoprotein that has a role in tumor progression. K17 is
overexpressed in SCC, triple negative breast cancer & others.
Aim of Study: This study aimed to explore the expression
of K17 protein in UC in bladder biopsies of Egyptian cases.
Also, to correlate K17 expression with the available clinicopathological
data of the studied cases.
Patients and Methods: This study was carried out on 60
cases of Egyptian bladder UC. Sections of the collected
paraffin blocks were performed and applied for Immunohistochemical
staining with K17, mouse monoclonal anti-human
K17 antibody. Positive K17 cases assessed for intensity
staining and distribution of positive stained cells into (mild,
moderate and strong) staining results.
Results: K17 showed high expression in UC Egyptian
patients biopsies (56.7%), strong intensity was found in more
than half of positive cases while it was negative in normal
urothelium. K17 is more expressed in papillary UC pattern
and more related to bad prognosis features as high grade and
muscle invasion. Significant association was detected between
positive K17 and squamous differentiation in UC cases. All
moderate intensity (100%) and majority of strong staining
(77.8%) were of papillary UC (p<0.001). In addition, significant
association was found between moderate & strong K17
intensity and negative schistosomiasis ovae cases (p=0.003).
Conclusion: Our study calls for considering high expression
of K17 in UC especially papillary pattern, high grade &
muscle invasion. This study also sheds light on significant
association of K17 in UC with squamous differentiation &
absence of Schistosomiasis.