Analysis of Chromosome-specific Aneusomy in Breast Tumor by Using Fluorescence in Situ Hybridization

ABSTRACT

PURPOSE: Several studies have used FISH (fluorescence in situ hybridization) to analyze aneuploids in various solid tumors. FISH, using chromosome-specific, alpha-stellite DNA probes, can be used to detect aneusomy in interphase and/or metaphase cells. The aims of this study were to compare the FISH cen tromere signals from benign breast tumors and to those from breast cancers and to evaluate the clinico pathologic parameters and the aneusomic patterns involving chromosomes 1, 11, and 17 in breast cancers. METHODS: FISH was performed on touch preparations from 15 benign breast-tumor and 29 breast-cancer specimens. The frequency of aneusomy, measured by nondisomy, was determined for chromosomes 1, 11, and 17 through the use of chromosome-specific alpha-stellite DNA probes. The frequency of chromosome- specific aneusomy was then correlated with clinicopathologic parameters, including tumor size, lymph- node involvement, estrogen receptor, and nuclear grade. RESULTS: Only one of the 15 benign breast tumors was shown to be aneusomic for chromosome 1. The other 14 cases of the benign breast tumors showed no evidence of aneusomy for any of the 3 chromosomes. In breast cancers, however, 26 of the 29 cases (90%) were exhibited aneusomy of at least 1 of the 3 chromosomes evaluated and chromosome 1 was most frequently aneusomic (26 of 29 cases (90%)). The present study also suggested a possible correlation between the numeric abnormality of chromosome 1 and estrogen receptor levels. No significant correlations with tumor size, regional lymph-node metastasis, and nuclear grade were observed. CONCLUSION: These findings suggest that chromosome-specific aneusomy is more frequently observed in breast cancers than in benign breast tumors and that aneusomy of chromosome 1 correlates with estrogen receptor levels.