c- myc Amplifications in primary breast carcinomas and their local recurrences

OBJECTIVE: To evaluate the role of c-myc oncogene amplifications in the progression of invasive breast carcinomas. METHODS: c-myc gene copy number was evaluated in a series of 49 primary breast carcinomas and the corresponding local recurrences using fluorescence in situ hybridisation. RESULTS: 11 of the primary carcinomas (22%) harboured c-myc amplifications; these tumours typically were hormone receptor negative and occurred in younger patients (43 v 53 years). At the time of relapse, six additional tumours had acquired a c-myc amplification. The mean recurrence-free survival was 24 months; c-myc amplified tumours relapsed significantly earlier than carcinomas without amplification (18 v 27 months). Univariate analysis showed a worse overall survival in these patients. CONCLUSIONS: While c-myc amplifications can be observed in early stage breast cancer, especially in younger patients, they often occur later in tumour development and appear to be associated with disease progression.