Interphase cytogenetics of chromosomes 11 and 17 in fine needle aspirates of breast cancer

The aims of this investigation were to compare quantitative with qualitative analysis of fluorescent in situ hybridization (FISH) centromere signals in interphase breast cancer cell nuclei and to evaluate the possible clinical utility of detecting numerical abnormalities of chromosomes 11 and 17 by FISH in the preoperative prediction of breast cancer histological grade. Commercial digoxigenin-labeled centromere probes to chromosomes 11 and 17 were hybridized to 69 malignant aspirates with histological follow-up. Aspirates were categorized as disomic or aneusomic for chromosomes 11 and 17 qualitatively; a subset of aspirates was also analyzed quantitatively. The quantitative and qualitative approaches resulted in almost identical categorisation. There was a significant association between the qualitative categorization of aspirates as aneusomic or disomic, the histological grade of the excised tumours (P = .0695, n = 69), and the cytological grade of the clinical aspirates (P = .006, n = 35). Although histological grade III tumors were almost invariably polysomic for one or both chromosomes, polysomy was also detected in grade I and II tumors. Qualitative FISH analysis was shown to be more sensitive than cytological grading in predicting histological grade III but was of lower specificity and was therefore not clinically useful.