Abstract: Objective:To explore the expression of liver fatty acid binding protein (L-FABP) in tissues of hilar cholangiocarcinoma and the relationship between expression of L-FABP and clinicopathological factors and prognosis of the patients.
Methods:The retrospective case-control study was conducted. The clinicopathological data of 132 patients with hilar cholangiocarcinoma who were admitted to the Navy General Hospital between January 2003 and January 2013 were collected. The expression of L-FABP in tumor tissues and adjacent tissues of hilar cholangiocarcinoma and normal bile duct tissues were respectively detected by immunohistochemistry. Observation indicators: (1) expression of L-FABP by immunohistochemistry; (2) relationship between clinicopathological factors of patients and expression of L-FABP in tumor tissues; (3) follow-up and survival situations; (4) prognostic analysis of patients after radical resection of hilar cholangiocarcinoma. Follow-up using outpatient examination and telephone interview was performed to detect postoperative overall survival time up to June 2017. Count data were described as percentage and compared using the chi-square test. The survival time was calculated by the Kaplan-Meier method. Measurement data with skewed distribution were described as M (range). The univariate analysis and multivariate analysis were respectively done using the nonparametric test and COX regression model.
Results:(1) Expression of L-FABP by immunohistochemistry: the positive expressions of L-FABP were located in the cytoplasm. The low, moderate and high expression rates of L-FABP in tumor tissues were respectively 11.36%(15/132), 71.97%(95/132) and 16.67%(22/132), and positive-staining cells showed platy and / or diffuse distribution; the low, moderate and high expression rates of L-FABP in adjacent tissues of hilar cholangiocarcinoma were respectively 77.27%(102/132), 7.58%(10/132) and 15.15%(20/132), and positive-staining cells showed scattered or platy distribution, with a weaker staining intensity compared with tumor tissues; there was no positive expression in normal bile duct tissues. There was a statistically significant difference in expressions of L-FABP among tumor tissues and adjacent tissues of hilar cholangiocarcinoma and normal bile duct tissues (x²=5.423, P<0.05). (2) Relationship between clinicopathological factors of patients and expression of L-FABP in tumor tissues: cases with low, moderate and high expressions of L-FABP in tumor tissues were respectively 10, 30, 5 in 45 patients with tumor diameter < 3 cm and 4, 29, 9 in 42 patients with 3 cm ≤ tumor diameter ≤ 5 cm and 1, 36, 8 in 45 patients with tumor diameter > 5 cm , with a statistically significant difference (x²=10.171, P< 0.05). (3) Follow-up and survival situations: 132 patients were followed up for 5-90 months, with a median time of 33 months. During the follow-up, postoperative overall median survival time of 132 patients was 31 months. (4) Prognostic analysis of patients after radical resection of hilar cholangiocarcinoma: results of univariate analysis showed that tumor differentiation, lymph node metastasis and expressions of L-FABP in tumor tissues were related factors affecting prognosis of patients after radical resection of hilar cholangiocarcinoma (Z=1.845, 3.156, 1.243, P<0.05). Results of multivariate analysis showed that tumor differentiation, lymph node metastasis and expressions of L-FABP in tumor tissues were independent factors affecting prognosis of patients after radical resection of hilar cholangiocarcinoma (odds ratio=0.431, 1.806, 3.692, 95% confidence interval: 0.292-0.693, 0.974-2.973, 1.875-11.364, P<0.05).
Conclusions:The high expression of L-FABP in tumor tissues is significantly correlated with the tumor diameter. Tumor differentiation, lymph node metastasis and expressions of L-FABP in tumor tissues are independent factors affecting prognosis of patients after radical resection of hilar cholangiocarcinoma.