title: Chromosome 9 deletions and recurrence of superficial bladder cancer: identification of four regions of prognostic interest.
abstract: In a previous study, loss of heterozygosity (LOH) of 28 chromosome 9 microsatellite markers was assessed on 139 Ta/T1 bladder tumors. LOH at one or more loci was detected in 67 tumors, 62 presenting subchromosomal deletions. One hundred and thirty-three of these patients have now been followed for up to 8 years. The purpose of the present study was to evaluate the potential biological significance of chromosome 9 deletions in superficial bladder tumors at initial diagnosis. High grade was associated with LOH (P=0.004). Large tumors carried more frequently 9p deletions (P=0.022). Female patients had more chromosome 9q LOH than male patients did (P=0.010). Chromosome 9 LOH at all loci was associated with an elevated risk of recurrence but four regions were associated with a particularly high risk of recurrence. Multivariate analysis taking into account grade, stage, size and number of tumors showed that tumors deleted in the regions 9ptr-p22, 9q22.3, 9q33, and 9q34 recurred significantly more rapidly than those without deletions (Recurrence rate ratio=2.32, 2.53, 2.52 and 2.43 respectively). Log-rank statistics comparing Kaplan-Meier survival curves for the same chromosomal regions confirmed the correlation (P=0.0002, 0.010, 0.002 and 0.009 respectively). Only four patients progressed to muscle-invasive disease. They all had extensive deletions on 9q but none had deletions at 9ptr-p22. This study suggests a link between chromosome 9 anomalies and recurrence of superficial bladder cancer.
authors.affiliation: Centre de recherche en cancérologie de l'Université Laval, Centre Hospitalier Universitaire de Québec, Pavillon L'Hôtel-Dieu de Québec, Québec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Simoneau
authors.forename: H
authors.initials: H
authors.lastname: LaRue
authors.forename: T O
authors.initials: TO
authors.lastname: Aboulkassim
authors.forename: F
authors.initials: F
authors.lastname: Meyer
authors.forename: L
authors.initials: L
authors.lastname: Moore
authors.forename: Y
authors.initials: Y
authors.lastname: Fradet
mesh_terms: D000368:Aged; D002899:Chromosomes, Human, Pair 9; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D005819:Genetic Markers; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality / Q000473:pathology
chemical_list: D005819:Genetic Markers