CELL-PROLIFERATION IN HYPERPLASTIC AND IN-SITU CARCINOMA LESIONS OF THE BREAST ESTIMATED BY IN-VIVO LABELING WITH BROMODEOXYURIDINE

The proliferative activity of normal, benign proliferative, and carcin oma in situ (CIS) breast lesions was studied by in vivo labeling with 5-bromodeoxyuridine (BrdU) in 35 patients with concurrent breast carci noma. The BrdU-labeled cells were identified on histologic sections by an anti-BrdU monoclonal antibody and an immunoperoxidase reaction. Th e percentage of BrdU-labeled cells in non-atypical hyperplasia (NAH) w as higher (1.15 +/- 1.14%) than normal epithelial cells (0.67 +/- 0.56 %, p = 0.066, borderline significance). This difference was very signi ficant in postmenopausal women and disappeared in premenopausal women. No significant difference was found in the fraction of proliferating cells between NAH and atypical hyperplasia (AH): 1.15 +/- 1.14% for NA H versus 1.26 +/- 1.19% for AH. In CIS and in invasive carcinoma (ICA) , a significant increase in the percent of BrdU-labeled cells was obse rved when compared to the normal epithelial cells or NAH (p < 0.001). No significant difference was found in the values of BrdU-labeled cell s between CIS and ICA (p = 0.29). The percent of BrdU-labeled cells in benign breast lesions, including fibroadenoma, papilloma, and scleros ing adenosis, did not differ from those of the normal epithelial cells . The menopausal status of the patients did not affect the proliferati ve activity in NAH or CIS. No correlation was found in the fraction of BrdU-labeled cells between the normal and hyperplastic epithelial cel ls (r(2) = 0.012) or between NAH and CIS (r(2) = 0.406) or between CIS and ICA (r(2) = 0.429). (C) 1994 Wiley-Liss, Inc.