02 BOOK OF ABSTRACTS .indd

Angiogenesis correlates with cycloogygenase-2
(COX-2) expression as well as with the tumour grade
in gallbladder carcinoma
Mateja Legan 1 , Bo{tjan Luzar 2 , Vera Ferlan Marolt 2 , Andrej Cör 1
1
Institute of Histology & Embryology, 2 Institute of Pathology, Medical Faculty
University of Ljubljana, Korytkova 2 , 1000 Ljubljana, Slovenia
Introduction and aim: Carcinoma of the gallbladder is an agressive tumor with an overall
5-year survival rate of less than 5%. Activation of the angiogenic pathways is common
and, by inducing new blood vessel formation, may have a decisive role in determining
local invasion, matestasis and clinical outcome. The proliferative endothelial antigen
CD105 (endoglin) essencial for angiogenesis and vascular development serves as a
marker of tumour neovasculature. Enhanced expression of cyclooxygenase-2 (COX-2)
was found in precancerous lessions and in gallbladder carcinoma, which is likely to
be involved in carcinogenesis as well as in angiogenesis.
The aim of the study was to investigate the relationships between the expression of
COX-2 and degree of vascularization, clinicopathological features and survival time of
patients with gallbladder carcinoma.
Materials and Methods: A retrospective analysis was performed on 27 gallbladder
adenocarcinoma tissue specimens obtained from patients operatively treated (11 male
and 16 female patients, mean age 66.5 +/- 11.0 years). Gallbladder adenocarcinomas
were classified according to the WHO classification of gallbladder tumours: 8 were
well-differentiated, 4 moderately and 15 poorly-differentiated.
The expression of COX-2 and CD105 was assessed by immunohistochemical method.
COX-2 expression was evaluated according to the percentage of positive cells and the
intensity of staining. Regarding immuno-reactive score gallbladder carcinomas were
divided into »COX-2 positive« and »COX-2 negative« groups. For microvessel count
(MVC) assessment the areas containing a large number of microvessels were identified.
Image analysis system LUCIA G (Nikon, Japan) was used for MVC quantification. The
average number of microvessels in 10 light microscopic field at 200x magnification was
recorded as the MVC for each tumour. Tumours were separated into hypervascular
and hypovascular group.
Results and conclusions: The MVC ranged from 9 to 46 (mean 25.6 +/- 9.2).15
tumours belonged to hypervascular group (mean microvessel count >= 25) and 12 to
hypovascular group (MVC