Endoglin expression as a measure of microvessel density in cervical cancer.
OBJECTIVE
To evaluate endoglin, a membrane protein and member of the transforming growth factor beta-1 receptor complex, as an endothelial marker of angiogenesis in cervical cancer tissues.


METHODS
Tumor tissue was collected from 31 surgically treated stage IB nonbulky (under 5 cm) cervical cancer subjects, and samples were fixed in formalin and embedded in paraffin. Endoglin was stained on 5-microm slide sections by the DAKO Catalyzed Signal Amplification method (DAKO Corporation, Carpinteria, CA). Factor VIII was stained by standard immunohistochemistry. Positively stained microvessels were counted in "hot spots" at 200x magnification. Clinical data were correlated with vessel counts by Spearman correlation. Mean differences in counts were tested using paired t tests.


RESULTS
This staining method for endoglin identified significantly more vessels than the factor VIII method (mean 92 +/- 45 versus 33 +/- 16, P <. 001). Endoglin and factor VIII counts correlated significantly with deep stromal invasion (Spearman rho 0.466 and 0.522, respectively, P <.05); however, only endoglin counts correlated significantly with lymph node metastases (rho =.495, P <.01).


CONCLUSIONS
Endoglin is stimulated in tumor angiogenesis and might be relatively more specific than commonly used endothelial markers. The endoglin system was more sensitive for staining capillaries in neoplastic cervical tissue, better predicted lymph node metastases, and should be widely applicable for the study of other tumors.
Brewer
C A
CA
Department of Obstetrics and Gynecology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61656, USA. bactd@uic.edu
Setterdahl
J J
JJ
Li
M J
MJ
Johnston
J M
JM
Mann
J L
JL
McAsey
M E
ME
D015703:Antigens, CD; D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism*; D001706:Biopsy; D000071063:Endoglin; D005169:Factor VIII / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D009389:Neovascularization, Pathologic / Q000175:diagnosis* / Q000473:pathology; D016612:Paraffin Embedding; D011956:Receptors, Cell Surface; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D002583:Uterine Cervical Neoplasms / Q000098:blood supply* / Q000378:metabolism* / Q000473:pathology; D019010:Vascular Cell Adhesion Molecule-1 / Q000032:analysis / Q000378:metabolism*
D015703:Antigens, CD; D014408:Biomarkers, Tumor; C064206:ENG protein, human; D000071063:Endoglin; D011956:Receptors, Cell Surface; D018125:Receptors, Transforming Growth Factor beta; D019010:Vascular Cell Adhesion Molecule-1; D005169:Factor VIII