Aneuploidy for chromosome 1 and overall DNA content in benign and malignant breast disease

Fluorescence in situ hybridization (FISH) with a probe for the pericentromeric region of chromosome 1 and DNA content measurements by image-analysis-based densitometry have been carried out on imprints of benign and malignant breast tissue. In general, an increase in the number of spots per nucleus was observed in the invasive carcinomas, with a large intercellular variation. In comparison with lymphocytes from controls, some cases of benign breast disease already had an increased frequency of aneusomy of chromosome 1, although they were all (near)diploid by DNA-content. However, an overall concordance between the DNA content measurements and the results of FISH was observed, although some exceptions were seen. A statistically significant correlation between the DNA index and the mean number of spots for chromosome 1 per nucleus was found. A linear discriminant analysis was applied on the data; the resulting classification of patients was most accurate when parameters describing DNA content and FISH results were combined.