HER 2 NEU and KI67 expression as immunolocalisation in colorectal carcinoma

BACKGROUND: This study was done to check the expression of HER-2 neu and Ki-67 expression in colorectal carcinoma with clinicopathological variables. Colorectal adenocarcinoma is the fourth most common malignant disease and it is the leading cause of morbidity and mortality. Both HER-2 neu and Ki-67 in immubohistochemical studies can be used for predicting the prognosis and treatment in colorectal carcinomas. AIMS AND OBJECTIVES: To study the expression pattern of HER2 neu and Ki67 expression of different grades in colorectal carcinomas and to observe the relationship in their staining patterns in various tumor stages. MATERIALS AND METHODS: The present study was conducted in 43 cases of histopathologically proven colorectal carcinoma cases and evaluated the clinicopathological patterns of colorectal carcinoma and the relationship of with the clinicopathological variables. RESULTS: HER 2 neu was positive in 88% of the cases. It was seen in 33% cases of well differentiated, 49% of moderately differentiated, 2% of poorly differentiated adenocarcinomas. Mucinous carcinomas showed 12% positivity for HER 2 neu. HER 2 neu positivity was more in grade III tumors compared to that in other grades. 33% of cases shows high proliferative index. There is a significant positive correlation between the lymph node status and Ki 67 proliferative index. CONCLUSION: Thus it was concluded that colorectal carcinomas which expresses HER2 neu could carry a poor prognosis and therefore require a different therapeutic approach, as these cases could respond to transtuzumab (Herceptin) therapy as well as other new modalities. Immunohistochemical technique for detection of Ki-67 proliferative index is simple and applicable to surgical specimens. However it is not enough to monitor Ki-67 proliferation index alone for prognosis in colorectal cancer as it was not significantly related to variable clinicopathologic parameters