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Updated: Aug 23, 2026
Comparison of Three Different Methods for Determining Cell Proliferation in Breast Cancer Cell Lines
Published on: September 3, 2016
A comparative study of breast cell proliferation during hormone replacement therapy: effects of tibolon and
P Conner1, A Christow, W Kersemaekers
1Department of Obstetrics and Gynecology, Karolinska Hospital, Stockholm, Sweden.
Objective:
To use the fine-needle aspiration (FNA) biopsy technique to compare the effects of tibolone, conventional hormone replacement therapy (HRT) and placebo on breast cell proliferation in postmenopausal women.
Methods:
A total of 91 women were randomized to receive either estradiol 2 mg plus norethisterone acetate 1 mg (E2/NETA), tibolone 2.5 mg or placebo for 6 months in a prospective double-blind trial. Breast cell proliferation was assessed using the Ki-67/MIB-1 monoclonal antibody.
Results:
From the 83 women who completed the study, a total of 166 FNA biopsies were obtained, and 118 of these aspirates (71%) were evaluable for MIB-1 content. Women with assessable biopsies were younger, had a lower body mass index, and had higher levels of sex hormone binding globulin and insulin-like growth factor-I than women in whom the cell yield was insufficient. During treatment with E2/NETA, there was an increase in proliferation (percentage of MIB-1) from a mean value of 2.2 to 6.4% after 6 months (p < 0.01). No significant changes were recorded during treatment with tibolone or placebo. There was a negative association between proliferation and serum levels of total (r(s) = -0.29, p < 0.05) and free (rs = -0.31, p < 0.03) testosterone.
Conclusions:
Tibolone seems to have little influence on breast cell proliferation.