DELETION OF THE SHORT ARM OF CHROMOSOME-3 IN BREAST-TUMORS

Deletions in the short arm of chromosome 3 have long been known to be common in many tumor types, including carcinomas of the lung and kidne y. Small interstitial deletions of the proximal-central region of 3p, with band 3p 14 as a minimal common deleted segment, have recently bee n shown to occur in as many as 10% of carcinomas of the breast, often as the only chromosomal change. Seemingly identical deletions may also be found in the epithelial cells of mixed-lineage benign tumors of th e breast and even in diffuse proliferative breast disease, a disorder that would not normally be accepted as neoplastic, but never in comple tely normal breast tissue. The cytogenetic evidence therefore indicate s that the putative tumor suppressor gene deleted from 3p14 influences cellular proliferation; evidently, its loss is often not sufficient f or a fully malignant phenotype to emerge. The first information about FHIT, a candidate suppressor gene recently identified in the FRA3B fra gile site in 3p 14 and found to be abnormal or lost in a high percenta ge of carcinomas of various organs, including breast, is compatible wi th such a general proliferation-regulating role. (C) 1997 Wiley-Liss, Inc.