Oligoclonality of early lesions of the urothelium as determined by microdissection-supported genetic analysis.
OBJECTIVE
To contribute to the ongoing discussion of clonality of human urothelial cancer it was considered a valuable approach to analyze multiple areas from cystectomy specimens for deletions of chromosomes known to be involved early in bladder cancer development.


METHODS
Thus, in 86 biopsies of 4 human cystectomies with different histological findings (maximal diagnosis: pT1G2, pTaG3, pT2G2, normal) loss of heterozygosity (LOH) was investigated as a deletion marker using markers of chromosomes 8p, 9p, 9q and 17p. Findings were compared to histology of the lesion.


RESULTS
Findings indicate: (1) no changes in the markers investigated in the bladder with histologically normal urothelium in contrast to detection of LOH in normal urothelium of tumour-bearing bladders; (2) an accumulation of the number of LOH with increasing malignancy of lesions within one bladder, and (3) indications of oligoclonal neoplastic lesions in two of the urinary bladders investigated.


CONCLUSIONS
The investigation of multiple lesions within one bladder presents a snapshot of genetic changes in differently advanced tumour stages. The hypotheses of tumour evolution and oligoclonality as derived from our LOH data need to be supported by deletion-independent clonality studies as X-chromosomal inactivation analysis.
Institute of Pathology, University of Regensburg, St. Josef Hospital, Regensburg, Germany.
R
R
Stoehr
A
A
Hartmann
E
E
Hiendlmeyer
K
K
Mürle
W
W
Wieland
R
R
Knuechel
D002278:Carcinoma in Situ / Q000235:genetics / Q000473:pathology; D002469:Cell Separation / Q000295:instrumentation / Q000379:methods; D002999:Clone Cells; D015653:Cystectomy; D004210:Dissection / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007834:Lasers; D018895:Microsatellite Repeats / Q000235:genetics; D016133:Polymerase Chain Reaction; D011230:Precancerous Conditions / Q000235:genetics / Q000473:pathology; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000473:pathology; D019459:Urothelium / Q000473:pathology*