Chromosomal aberrations in transitional cell carcinoma that are predictive of disease outcome are independent of polyploidy.
OBJECTIVE
To determine whether aneusomy for chromosomes 7, 9 and 17 (reported to predict recurrence in up to 65% of patients with superficial transitional cell bladder cancer and thus providing the opportunity for early and effective treatment) reflects specific genetic events on these chromosomes or merely wider unspecific genetic damage to the cell, e.g. that increased copy numbers for 7 and 17 reflect tumour polyploidy.


METHODS
The study comprised 25 primary tumours; 6 microm thick sections from formalin-fixed and paraffin-embedded tumours were analysed. Chromosome copy numbers were determined by fluorescence in situ hybridization (FISH) using pericentromeric probes for chromosomes 7, 8, 9, 10, 11 and 17. A minimum of 200 nuclei per tumour area were scored by two independent observers.


RESULTS
Eight of the 25 tumours examined (32%) showed no evidence of chromosomal abnormalities as detected by FISH for any chromosomes analysed. Twelve tumours (48%) showed abnormalities for one or two chromosomes, five tumours (20%) showed abnormalities for multiple chromosomes and one tumour showed abnormalities for all chromosomes analysed, suggestive of polyploidy.


CONCLUSIONS
Chromosomal abnormalities predictive of recurrence occur largely in the absence of other gross chromosomal lesions. In a small proportion of cases other chromosomes are affected, but this is almost always distinct from tumour polyploidy.
Bartlett
J M
JM
University Department of Surgery, Glasgow Royal Infirmary, Scotland, UK. gqva20@udcf.gla.ac.uk
Adie
L
L
Watters
A D
AD
Going
J J
JJ
Grigor
K M
KM
D002295:Carcinoma, Transitional Cell / Q000235:genetics*; D002869:Chromosome Aberrations / Q000235:genetics*; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000235:genetics; D009367:Neoplasm Staging / Q000379:methods; D011123:Polyploidy; D011379:Prognosis; D012189:Retrospective Studies; D001749:Urinary Bladder Neoplasms / Q000235:genetics*