This work was performed at Breast Cancer Research Laboratory, Fox Chase Cancer Center, Philadelphia, PA, USA. We employed the technique of laser capture microdissection to obtain selected chosen cells without contamination of other cells that could interfere with final results of molecular analysis. Results confirmed that genetic alterations at specific loci of 9p occur earlier than discernable morphological or histopathological alterations and the presence of genetic alterations within morphologically normal breast tissue adjacent to carcinoma foci was also assessed.