LOH analyses of premalignant and malignant lesions of human breast: frequent LOH in 8p, 16q, and 17q in atypical ductal hyperplasia.

The number of breast cancer patients is increasing yearly, and it is important to establish effective methods for clinical management. We investigated loss of heterozygosity (LOH) in tumors derived from 23 patients that harbored synchronous lesions of atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS), and invasive ductal carcinoma (IDC). Fourteen selected microsatellite markers that were mapped to and/or very close to the tumor suppressor genes or regions with frequent LOH in breast cancer. Our results suggested that i) losses of chromosomal regions 8p, 16q, and 17q are early genetic changes, and ii) ADH is a premalignant lesion for the development of breast cancer.