Published online Dec 15, 2003. doi: 10.3748/wjg.v9.i12.2817
Revised: June 13, 2003
Accepted: July 24, 2003
Published online: December 15, 2003
AIM: To investigate the relationship between the expression of P-glycoprotein (P-gp) and the degree of vascularization in gallbladder carcinomas.
METHODS: P-gp was stained with streptavidin-peroxidase complex immunohistochemical method in routine paraffin-embedded sections of gallbladder carcinomas. Microvessel counts (MVC) were determined using factor-VIII-related antigens.
RESULTS: The average MVC in 32 cases of gallbladder carcinomas was (34 ± 10)/HP. The value of MVC was closely correlated with Nevin staging and tumor differentiation (P < 0.01 and P < 0.05). The total expression rate of P-gp was 62.5%. The P-gp expression rate in cases of Nevin staging S1-S3 (78.6%) was higher than that of S4-S5 (50.0%) with no statistical significance. The P-gp expression rate was not correlated with tumor differentiation or pathologic types. The value of MVC in P-gp (+) cases was markedly lower than that in P-gp (-) cases (P < 0.01). The positive rate of P-gp was significantly higher in cases of smaller MVC than those of bigger MVC (P < 0.05).
CONCLUSION: MVC may be used as one of the important parameters to reflect the biological behaviors of gallbladder carcinomas. As a major cause of drug resistance, the overexpression of P-gp is closely correlated with the poor vascularization in gallbladder carcinomas.