Genetic aberrations of c-myc and CCND 1 in the development of invasive bladder cancer

Abstract

Detrusor muscle invasive transitional cell carcinoma is associated with poor prognosis and is responsible for the majority of bladder cancer related deaths. Amplifications of c-myc and CCND 1 are associated with detrusor-muscle-invasive transitional cell carcinoma, however, their precise role in driving disease progression is unclear. Fluorescence in situ hybridisation on archival tissue from 16 patients with primary diagnosis of ≥ pT2 transitional cell carcinoma and 15 cases with primary pTa/pT1 disease subsequently progressing to detrusor-muscle-invasion was performed, in the latter group both pre and post muscle invasive events were studied. No patients presenting with ≥ pT2 had amplification of c-myc, two out of 16 (12.5%) had CCND 1 amplification. Of patients who developed ≥ pT2, two out of 15 (13.3%) had amplification of c-myc, both in ≥ pT2, five out of 15 (33.3%) had CCND 1 amplification, two in pTa/pT1 tumours, three in ≥ pT2 transitional cell carcinomas. In total, two out of 31 (6.5%) of patients' ≥ pT2 TCCs were amplified for c-myc and six out of 31 (19%) were amplified for CCND 1. Eighty-seven per cent (40 out of 46) of tumours were polysomic for chromosome 8 and 80% (37 out of 46) were polysomic for chromosome 11 and this reflected the high copy numbers of c-myc and CCND 1 observed. In almost all cases an increase in c-myc/CCND 1 copy number occurred prior to invasion and persisted in advanced disease. Amplification of CCND 1 or alterations in c-myc/CCND 1 early in bladder cancer may have clinical relevance in promoting and predicting progression to detrusor-muscle-invasive transitional cell carcinoma. © 2002 Cancer Research UK.