ABSTRACT
In this article, breast cancer and surrounding normal mammary epithelium was microdissected from patients with cancer. Malignant cells as well as morphologically normal cells at a distance from the primary tumor were analyzed for loss of heterozygosity (LOH). A significant degree of LOH (a surrogate for genetic alteration) was identified in apparently normal tissue. The conclusion of the work is that genetic changes in the breast precede morphologic evidence for malignant transformation.
