Expression of carbonic anhydrase IX (CA IX), a hypoxia-related protein, rather than vascular-endothelial growth factor (VEGF), a pro-angiogenic factor, correlates with an extremely poor prognosis in esophageal and gastric adenocarcinomas.
OBJECTIVE
To evaluate the expression of carbonic anhydrase IX (CA IX) and vascular-endothelial growth factor (VEGF) in esophageal and gastric adenocarcinomas and in turn with the histologic subtype.


BACKGROUND
Tumor hypoxia is an important factor in therapy resistance. A low oxygen concentration in tumors stimulates a.o. the expression of CA IX, a marker of hypoxia, and VEGF, a pro-angiogenic factor.


METHODS
We evaluated the immunohistochemical expression of CA IX and VEGF on paraffin-embedded material of 154 resection specimens: 39 esophageal, 73 cardiac, and 42 distal gastric adenocarcinomas (UICC classification). The adenocarcinomas were subtyped according to the Lauren classification (intestinal- and diffuse-type).


METHODS
chi test, Kaplan-Meier survival analysis, log-rank test, and Cox proportional hazards model.


RESULTS
CA IX and VEGF expression were independent of the localization of the tumor. However, intestinal-type adenocarcinomas showed a significantly higher expression of CA IX as well as VEGF than diffuse-type tumors. VEGF expression was associated with a high microvessel density. Although survival analysis showed that CA IX expression (P = 0.008) as well as the coexpression of CA IX and VEGF (P = 0.008) correlate with a poor outcome, only CA IX expression is an independent prognostic factor for overall survival and metastasis-free survival.


CONCLUSIONS
The difference in expression of CA IX and VEGF between intestinal- and diffuse-type adenocarcinomas may possibly explain the different clinical behavior of these tumors. CA IX expression, rather than VEGF positivity in tumors, enables the identification of a subpopulation, characterized by a more aggressive behavior and a poorer prognosis.
Driessen
Ann
A
Department of Pathology, University Hospital Maastricht, Maastricht, The Netherlands. adri@lpat.azm.nl
Landuyt
Willy
W
Pastorekova
Sylvia
S
Moons
Johnny
J
Goethals
Laurence
L
Haustermans
Karin
K
Nafteux
Philippe
P
Penninckx
Freddy
F
Geboes
Karel
K
Lerut
Toni
T
Ectors
Nadine
N
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000096:biosynthesis*; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis*
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D042461:Vascular Endothelial Growth Factor A; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases