Carbonic anhydrase IX expression and outcome after radiotherapy for muscle-invasive bladder cancer.
OBJECTIVE
Carbonic anhydrase IX (CA IX) expression has been described as an endogenous marker of hypoxia in solid neoplasms. Furthermore, CA IX expression has been associated with an aggressive phenotype and resistance to radiotherapy. We assessed the prognostic significance of CA IX expression in patients with muscle-invasive bladder cancer treated with radiotherapy.


METHODS
A standard immunohistochemistry technique was used to show CA IX expression in 110 muscle-invasive bladder tumours treated with radiotherapy. Clinicopathological data were obtained from medical case notes.


RESULTS
CA IX immunostaining was detected in 89 ( approximately 81%) patients. Staining was predominantly membranous, with areas of concurrent cytoplasmic and nuclear staining and was abundant in luminal and perinecrotic areas. No significant correlation was shown between the overall CA IX status and the initial response to radiotherapy, 5-year bladder cancer-specific survival or the time to local recurrence.


CONCLUSIONS
The distribution of CA IX expression in paraffin-embedded tissue sections seen in this series is consistent with previous studies in bladder cancer, but does not provide significant prognostic information with respect to the response to radiotherapy at 3 months and disease-specific survival after radical radiotherapy.
Sherwood
B T
BT
Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester LE1 7RH, UK.
Colquhoun
A J
AJ
Richardson
D
D
Bowman
K J
KJ
O'Byrne
K J
KJ
Kockelbergh
R C
RC
Symonds
R P
RP
Mellon
J K
JK
Jones
G D D
GD
D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000378:metabolism*; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000378:metabolism*; D018572:Disease-Free Survival; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D001749:Urinary Bladder Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy*
D000951:Antigens, Neoplasm; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases