Immunohistochemical expression of Ki-67 as a marker of proliferation in gallbladder mucosa samples with or without cancer

Abstract

There is paucity of knowledge on the proliferative features of normal or chronically inflamed gallbladder and the mechanisms of development of gallbladder cancer. To study the proliferation features of non tumoral gallbladder mucosa through the expression of Ki-67 antigen in tissue micro array analysis. The immunohystochemical expression of Ki-67 in tissue micro array was studied in 96 samples of non tumoral gallbladder mucosa (coming from 74 females aged 45+/-16 years and 22 males aged 53+/-16 years) and 102 samples of gallbladder cancer (coming from 84 females aged 62+/- 14 years and 18 males aged 70+/- 13 years). The staining index of Ki-67 expression was 19+/-25% (range 096-8996) in samples of non tumoral mucosa and 46+/-29% (range 396-9896) in gallbladder cancer (p <0.01). Ki-67 was expressed in less than 10% of epithelial cells in 55% of non tumoral mucosa samples and 6% of gallbladder cancer samples. Seventy five percent of gallbladder cancer samples had a staining index of more than 20%. An expression of Ki-67 over 20% or 50% was observed in 25% and 15% of non tumoral mucosa samples, respectively. Non tumoral gallbladder mucosa samples have a high proliferation index, measured using Ki-67 immunohystochemical expression. There is a group of samples with cellular hyper-proliferation that maybe related to the pathogenesis of gallbladder cancer.