Inverse correlation between CD8(+) inflammatory cells and E-cadherin expression in gallbladder cancer: Tissue microarray and imaging analysis

AIM: To investigated the association between the tumor cells’ expression of E-cadherin and the numbers of several types of inflammatory cells infiltrating into the invasive portion of gallbladder cancer (GBC). METHODS: We analyzed 50 GBC cases for which a sufficient amount of tumor tissues for tissue microarray (TMA) had been saved. Three tissue cores (3.0 mm) of invasive lesion from each case were used for the TMA. The 4-μm cut sections on slides were immunostained using primary antibodies including E-cadherin for cancer cells, leukocyte common antigen for leukocyte, myeloperoxidase for neutrophils, CD3 for T cells, CD4 for helper T cells, CD8 for killer T cells, CD20 for B cells and CD68 for macrophages. The immunostained slides were digitally analyzed by imaging analysis software. RESULTS: A significant inverse correlation between the number of infiltrating CD8(+) cells at invasive areas and the expression of E-cadherin by cancer cells was observed (P = 0.0001), although the degree of this correlation was relatively weak (R = 0.32). The number of CD8(+) cells and the cancer cells’ E-cadherin expression were also significantly correlated with tumor differentiation (well-differentiated vs poorly differentiated) (P = 0.0467 and P = 0.0294, respectively). Inverse correlation of T-stage and the number of CD8(+) cell infiltration was observed with statistical significance in comparison of T2 and T3 cases (P = 0.0324). CONCLUSION: Our findings indicate an inverse correlation of CD8(+) T cell infiltration and cancer cells’ E-cadherin expression at invasive areas of GBC. Further analyses are essential to test these findings.