Evaluation of numeric alterations of chromosomes 1 and 17 by in situ hybridization in invasive breast carcinoma with clinicopathologic parameters.

Breast cancer is a genetically complex disease and is frequently associated with nonrandom chromosomal alterations. The occurrence of aberrations involving chromosomes 1 and 17 in malignant tissues of breast cancer patients has not been studied systematically. The numeric aberrations of chromosomes 1 and 17 were detected by nonisotopic in situ hybridization on paraffin-embedded tissue sections from 44 invasive breast carcinomas (42 cases available for chromosome 17) and were correlated with clinicopathologic parameters, patients' survival, p53, and c-erbB-2 proteins. Chromosome 17 and 1 aneuploidy were observed in the majority of breast carcinomas with equal percentages of polysomy and monosomy for chromosome 17 and predominance of polysomy for chromosome 1. Monosomy of chromosome 17 was significantly associated with positive lymph nodes and negative estrogen receptor (ER) immunohistochemical expression. Patients with chromosome 17 monosomy were at greater risk of death. Ductal carcinoma displayed a greater percentage of chromosome 1 polysomy than lobular ones. A statistically significant association was demonstrated between chromosome 1 polysomy and higher nuclear grade. Patients with chromosome 1 aneuploidy were at greater risk of death, and especially those with ER negativity. Aneuploid patients with c-erbB-2(-)/PR(-) phenotype demonstrated lower survival rates. These data suggest a possible susceptibility of chromosome 17 to losses and gains and chromosome 1 to gains. Chromosome 17 monosomy and chromosome 1 aneuploidy may be useful prognostic markers in breast cancer patients.