Cytogenetics of benign breast lesions

This review summarizes the cytogenetic information on benign breast lesions of various histologies, i,e., fibrocystic lesions from women with and with out a known hereditary predisposition to breast cancer, fibroadenomas, phyl lodes tumors, and papillomas, and relate the chromosomal features with thos e in breast carcinoma. In general, the frequency of chromosome abnormalitie s is lower ill benign lesions than in breast cancer, and seems to correlate wi th the histologic features of the tissue, and the: corresponding risk o f developing invasive mammary carcinoma; aberrations are more common in pro liferative than in nonproliferative lesions. The karyotypes are generally l ess complex than those detected in invasive carcinoma, and more often invol ve balanced rearrangements, No lesion-specific aberration has so far been d etected, on the contrary, changes repeatedly encountered in breast cancer s amples: can be found in benign lesions as well, e,g., gain of Iq, interstit ial deletion of 3p, and trisomies 7, 18, and 20. Especially intriguing is t he prevalence of rearrangements of the short arm of chromosome 3, with the minimally deleted bands 3p13-14, in proliferative lesions from prophylactic mastectomies in breast cancer families. The potential tumor suppressor gen e(s) in this region remains, however, to be identified.