Objective: To investigate the protein expressions of RCAS1/EBAG9 and P53 in intrahepatic cholangiocarcinoma (ICC) tissue and their clinical significance.
Methods: The protein expressions of RCAS1/EBAG9 and P53 in 41 specimens of ICC tissue and 9 specimens of normal bile duct tissue were detected by immunohistochemcal staining. The relations of RCAS1/EBAG9 and P53 protein expressions with the clinicopathologic characteristics and prognosis of the patients were analyzed.
Results: The positive expression rates of both RCAS1/EBAG9 and P53 proteins in ICC tissue were significantly higher than those in normal bile duct tissue (both P<0.05). The RCAS1/EBAG9 protein expression was significantly related to tumor size, pathological grade, TNM stage and lymph node metastasis, while P53 protein expression was significantly associated with tumor size, pathological grade, and TNM stage (all P<0.05). There was a positive correlation between RCAS1/EBAG9 and P53 protein expression in ICC tissue (r=0.329, P=0.018). The overall postoperative survival time in patients with negative RCAS1/EBAG9 or P53 protein expression was significantly longer than that in patients with positive RCAS1/EBAG9 or P53 protein expression (χ2=3.862, P=0.049; χ2=4.977, P=0.026). Results of univariate and multivariate Cox regression analysis showed that RCAS1/EBAG9 protein expression was an independent risk factor for the prognosis of ICC patients (HR=3.657, 95% CI= 1.111–12.040, P=0.033).
Conclusion: The RCAS1/EBAG9 and P53 protein expressions are increased in ICC tissue, and are closely associated with unfavorable clinicopathologic features and outcomes of the ICC patients, in which, the RCAS1/EBAG9 may probably play a causal role.