Abstract:
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Background: Bilharzia-associated bladder cancer (BAC) is a major health problem in countries
where urinary schistosomiasis is endemic. Characterization of the genetic alterations in this cancer
might enhance our understanding of the pathogenic mechanisms of the disease but, in contrast to
nonbilharzia bladder cancer, BAC has rarely been the object of such scrutiny. In the present study,
we aimed to characterize chromosomal imbalances in benign and malignant post-bilharzial lesions,
and to determine whether their unique etiology yields a distinct cytogenetic profile as compared
to chemically induced bladder tumors.
Methods: DNAs from 20 archival paraffin-embedded post-bilharzial bladder lesions (6 benign and
14 malignant) obtained from Sudanese patients (12 males and 8 females) with a history of urinary
bilharziasis were investigated for chromosomal imbalances using comparative genomic
hybridization (CGH). Subsequent FISH analysis with pericentromeric probes was performed on
paraffin sections of the same cases to confirm the CGH results.
Results: Seven of the 20 lesions (6 carcinomas and one granuloma) showed chromosomal
imbalances varying from 1 to 6 changes. The most common chromosomal imbalances detected
were losses of 1p21-31, 8p21-pter, and 9p and gain of 19p material, seen in three cases each,
including the benign lesion.
Conclusion: Most of the detected imbalances have been repeatedly reported in non-bilharzial
bladder carcinomas, suggesting that the cytogenetic profiles of chemical- and bilharzia-induced
carcinomas are largely similar. However, loss of 9p seems to be more ubiquitous in BAC than in
bladder cancer in industrialized countries. |