Chromosomal aneusomy (chr 1, 11, 17) detected by fluorescence in situ hybridization may be a prognostic factor in breast cancer.

The relationship between clinicopathological findings and the long-term prognosis was investigated in 42 breast cancer patients in whom aneusomy was detected for chromosomes 1, 11 and 17. The frequencies of aneusomy of those chromosomes were 78.6%, 47.5% and 52.5%, respectively, and more than 90% of anomalies consisted of polysomy. The relationship between aneusomy and the clinicopathological findings showed a statistical correlation with a high histological grade in the case of polysomy of chromosome 17 compared with disomy, indicating a tendency for a high incidence of lymph node metastasis. Analysis of the survival data revealed that the prognosis was poor when there was polysomy of chromosomes 1 or 11. These results indicate the possibility that aneusomy of chromosomes 1, 11 and 17 can serve as prognostic factors of poor outcome in breast cancer patients.