The role of HER2 Gene Mutation in Transitional Cell Carcinoma

The urinary bladder cancer (UBC ) are most common type of cancer of the urinary tract. It is regarded as the second and the fourth most common cancer types for males in Iraq and in the United State of America (USA) respectively and as tenth and eleventh most common cancer types for females in both Iraq and USA respectively. HER2/neu protein is glycoprotein produced by HER2 gene which lies in 17q21 (long arm of chromosome 17). This glycoprotein is normally found in lung, breast, urinary bladder, prostate and stomach, and its cytoplasmic portion has enzymatic function (tyrosine kinase activity). This receptor is responsible for the cell survival, normal cell growing and inhibition of apoptosis. HER2/neu protein overexpression is measured by IHC, but when the result of IHC is equivocal to HER2/neu protein (+ 2), Then, HER2 gene amplification is measured by using an accurate and more practical CISH method Several clinical trials are currently investigating the benefit of HER2-targeted therapy in urothelial bladder cancer. Patients with HER2 amplified UBC could potentially profit from these therapies.