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

The aims of this investigation were to compare quantitative with qualitativ e analysis of fluorescent in situ hybridization (FISH) centromere signals i n interphase breast cancer cell nuclei and to evaluate the possible clinica l utility of detecting numerical abnormalities of chromosomes 11 and 17 by FISH in the preoperative prediction of breast cancer histological grade. Co mmercial digoxigenin-labeled centromere probes to chromosomes 11 and 17 wer e hybridized to 69 malignant aspirates with histological follow-up. Aspirat es were categorized as disomic or aneusomic for chromosomes 11 and 17 quali tatively; a subset of aspirates was also analyzed quantitatively. The quant itative and qualitative approaches resulted in almost identical categorisat ion. There was a significant association between the qualitative categoriza tion of aspirates as aneusomic or disomic, the histological grade of the ex cised tumours (P=.0695, n = 69), and the cytological grade of the clinical aspirates (P =.006, n = 35). Although histological grade III tumors were al most invariably polysomic for one or both chromosomes, polysomy was also de tected in grade I and IT tumors. Qualitative FISH analysis was shown to be more sensitive than cytological grading in predicting histological grade II I but was of lower specificity and was therefore not clinically useful. HUM PATHOL 30:137-144. Copyright (C) 1999 by W.B. Saunders Company.