BACKGROUND: This study was conducted to compare breast epithelial-cell proliferation and estrogen and progesterone receptor levels in women taking one of two oral contraceptives (OCs) containing the same dose of estrogen but different doses of theprogestin norethindrone (NET). STUDY DESIGN:Thirty-three women were randomly assigned 1:1 to one of two OCs with 35-mcg ethinylestradiol (EE2) but different doses of NET - 1 or 0.4 mg. At the end of the active pill phase of the third OC cycle, a breast biopsy was performed and the percentages of epithelial cells of the terminal duct lobular units were measured for Ki67 (MIB1), progesterone receptors A and B (PRA and PRB, respectively), and estrogen receptorα (ERα). RESULTS: The biopsies from 27 women had sufficient epithelium for analysis. The percentages of cells positive for PRA, PRB and ERα were approximately double with the lower progestin dose (PRA: p=.041; PRB: p=.030; ERα: p=.056). The Ki67 percentage was not reduced with the lower progestin dose (12.5% for 0.4-mg NET vs. 7.8% for 1.0-mg NET). CONCLUSIONS: The increase in PRA-, PRB- and ERα-positive cells with the 60% lower progestin dose OC appears likely to account for its failure to decrease breast-cell proliferation. This breast-cell proliferation result is contrary to that predicted from the results of lowering the medroxyprogesterone acetate dose in menopausal hormone therapy.
RCT Entities:
BACKGROUND: This study was conducted to compare breast epithelial-cell proliferation and estrogen and progesterone receptor levels in women taking one of two oral contraceptives (OCs) containing the same dose of estrogen but different doses of the progestin norethindrone (NET). STUDY DESIGN: Thirty-three women were randomly assigned 1:1 to one of two OCs with 35-mcg ethinylestradiol (EE2) but different doses of NET - 1 or 0.4 mg. At the end of the active pill phase of the third OC cycle, a breast biopsy was performed and the percentages of epithelial cells of the terminal duct lobular units were measured for Ki67 (MIB1), progesterone receptors A and B (PRA and PRB, respectively), and estrogen receptor α (ERα). RESULTS: The biopsies from 27 women had sufficient epithelium for analysis. The percentages of cells positive for PRA, PRB and ERα were approximately double with the lower progestin dose (PRA: p=.041; PRB: p=.030; ERα: p=.056). The Ki67 percentage was not reduced with the lower progestin dose (12.5% for 0.4-mg NET vs. 7.8% for 1.0-mg NET). CONCLUSIONS: The increase in PRA-, PRB- and ERα-positive cells with the 60% lower progestin dose OC appears likely to account for its failure to decrease breast-cell proliferation. This breast-cell proliferation result is contrary to that predicted from the results of lowering the medroxyprogesterone acetate dose in menopausal hormone therapy.
Authors: Polly A Marchbanks; Jill A McDonald; Hoyt G Wilson; Suzanne G Folger; Michele G Mandel; Janet R Daling; Leslie Bernstein; Kathleen E Malone; Giske Ursin; Brian L Strom; Sandra A Norman; Phyllis A Wingo; Ronald T Burkman; Jesse A Berlin; Michael S Simon; Robert Spirtas; Linda K Weiss Journal: N Engl J Med Date: 2002-06-27 Impact factor: 91.245
Authors: E Isaksson; L Sahlin; G Söderqvist; E von Schoultz; B Masironi; M Wickman; N Wilking; B von Schoultz; L Skoog Journal: J Steroid Biochem Mol Biol Date: 1999 Sep-Oct Impact factor: 4.292
Authors: E Isaksson; E von Schoultz; V Odlind; G Söderqvist; G Csemiczky; K Carlström; L Skoog; B von Schoultz Journal: Breast Cancer Res Treat Date: 2001-01 Impact factor: 4.872
Authors: M D Althuis; D R Brogan; R J Coates; J R Daling; M D Gammon; K E Malone; J B Schoenberg; L A Brinton Journal: Br J Cancer Date: 2003-01-13 Impact factor: 7.640
Authors: Carolyn L Westhoff; Hua Guo; Zhong Wang; Hanina Hibshoosh; Margaret Polaneczky; Malcolm C Pike; Richard Ha Journal: Breast Cancer Res Treat Date: 2022-01-11 Impact factor: 4.624
Authors: Steven S Yu; Darcy V Spicer; Debra Hawes; Chiu-Chen Tseng; Chung S Yang; Malcolm C Pike; Anna H Wu Journal: Front Oncol Date: 2013-12-13 Impact factor: 6.244