Immunohistochemical expression of Ki-67 in gall bladder carcinoma

Introduction: Gall bladder carcinoma accounts for 0.3-0.7% of all cancers and has a peak incidence among women aged 70 and 79 years. Recently many molecular markers like Ki-67, cyclin D1, MUC1 and p53 with prognostic impact on GBC have been described. Ki-67 is a proliferative marker which is expressed in all active phases of the cell cycle and it can be detected in the nucleus of tumour cells indicating its proliferative activity. The aim of this study is to evaluate the expression of Ki-67 in carcinoma of gall bladder by immunohistochemistry and to correlate the mean Ki-67 labelling index with the various histological grades of gallbladder carcinoma. Materials and Methods: All the histopathologically proven cases of gall bladder malignancy from July 2014 to June 2017 (n=44) were examined for Ki-67 expression immunohistochemically.Ki-67 labelling index was calculated. ANOVA test and independent ‘t' test were applied to see correlation of Ki-67 expression with various grades of gall bladder carcinoma. Results: The Ki-67 labelling index was minimum in well-differentiated adenocarcinoma of gall bladder and maximum in poorly differentiated adenocarcinoma of gall bladder. The p value amongst these groups was found to be statistically significantly different. Conclusion: 88.64% of Gall bladder carcinoma was positive for Ki-67 and the Ki-67 labelling index increased significantly as the histological grade increased.