[Result of p53, ki-67 protein expression in cholangiocarcinoma with in situ hybridization and immunohistochemistry methods].

OBJECTIVE

To clarify the clinical significance of P53, ki-67, and the relationship between p53 gene expression and ki-67 labeling index.

METHODS

In this study, 30 cases of human cholangiocarcinoma, paired with normal bile duct tissue adjacent to the tumor, were included. In situ hybridization (ISH) was used to detect the p53 gene expression. Immunohistochemistry (IHC) was applied to analyze p53 gene mutation and ki-67 labelling index.

RESULTS

ki-67 and P53 positivity were detected in 96.7% (29/30) and 53.3% (16/30) of carcinoma specimens respectively by IHC, neither in peripheral normal tissue. p53 positivity was related to local lymph node metastasis. p53 positivity of cholangiocarcinoma in clinical stage III was significantly higher than that in clinical stage I, II. The expression of ki-67 protein was correlated with local lymph node metastasis and clinical stage. In lymph node metastasis group and clinical stage III group, ki-67 labeling index was significantly higher than that in non-lymph node metastasis group as well as in early stage group. We also found ki-67 labeling index of moderately or poorly differentiated cholangiocarcinoma was significantly higher than that of well differentiated carcinoma. Comparing survival time, the median survival time of patients whose bile duct tumors expressed no P53 protein or with lower ki-67 index was longer than that of patients whose tumors expressed P53 protein, or with higher ki-67 labeling index.

CONCLUSIONS

The results indicate that p53 positivity may be correlated with tumor development, growing activity. They also indicate that ki-67 labeling index reflects the degree of tumor cell proliferation. This observation suggests that ki-67 labeling index may be a useful predictor of tumor prognosis.