title: The endometrial response to sequential and continuous combined oestrogen-progestogen replacement therapy.
abstract: OBJECTIVE
  1. To determine the prevalence of endometrial hyperplasia in postmenopausal women taking standard proprietary regimens of sequential oestrogen/progestogen; 2. to determine the effects of nine months treatment with an oral continuous combined regimen of 2 mg 17beta-oestradiol and 1 mg norethisterone acetate (Kliofem [Kliogest outside the UK]; Novo Nordisk, Denmark) on endometrial histology in postmenopausal women.
  
  
  METHODS
  An open, prospective study in postmenopausal women.
  
  
  METHODS
  Fifty-four menopause clinics in the UK.
  
  
  METHODS
  2028 postmenopausal women: 1312 (Group A) taking sequential oestrogen-progestogen hormone replacement therapy (HRT), and 716 (Group B) not taking HRT, were recruited. In Group A, 388 women took preparations containing 10 days of progestogen, 921 had 12 days, and 3 had 13 days per cycle.
  
  
  METHODS
  Endometrial aspiration biopsies were taken towards the end of a three-month run-in period (Group A) or at study entry (Group B), before administration of the continuous combined HRT regimen. Biopsies were repeated at the end of the nine month treatment period.
  
  
  METHODS
  Endometrial histology.
  
  
  RESULTS
  Initial endometrial biopsy data were available for 1106 women in Group A, who by the time of endometrial investigation had been taking HRT for a median duration of 2.56 years (5th to 95th centiles: 0.77 to 8.49 years). Data were available for 661 untreated women, who had no bleeding and had not taken HRT within the last year (Group B). Complex hyperplasia was found in 59 women (5.3%), and atypical hyperplasia in a further eight (0.7%) in Group A. In Group B there were no cases with complex hyperplasia, but one woman showed atypical hyperplasia (0.2%). At the end of the nine months of continuous combined therapy there was no case of hyperplasia among 1196 biopsies (upper 95% confidence limit of risk 0.31%) in women completing the study. Within this Group all of the women with complex hyperplasia arising during previous sequential HRT and who completed the study (n = 38) reverted to normal endometrial patterns. There was no case of endometrial carcinoma during the study.
  
  
  CONCLUSIONS
  Despite taking standard regimens of sequential HRT containing at least 10 days of progestogen, there was a 5.3% prevalence of complex endometrial hyperplasia, and a 0.7% prevalence of atypical hyperplasia. However, continuous combined HRT (Kliofem) containing daily progestogen is not associated with an increased risk of hyperplasia and will convert the endometrium to normal in those with complex hyperplasia arising during previous sequential HRT.
authors: Women's Health Unit, Birmingham Heartlands and Solihull Hospital NHS Trust, West Midlands, UK.
authors: D W
authors: DW
authors: Sturdee
authors: L G
authors: LG
authors: Ulrich
authors: D H
authors: DH
authors: Barlow
authors: M
authors: M
authors: Wells
authors: M J
authors: MJ
authors: Campbell
authors: M P
authors: MP
authors: Vessey
authors: B
authors: B
authors: Nielsen
authors: M C
authors: MC
authors: Anderson
authors: A J
authors: AJ
authors: Bragg
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D004338:Drug Combinations; D004714:Endometrial Hyperplasia / Q000139:chemically induced* / Q000473:pathology; D004958:Estradiol / Q000008:administration & dosage / Q000009:adverse effects*; D045166:Estradiol Congeners / Q000008:administration & dosage / Q000009:adverse effects*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D008875:Middle Aged; D009640:Norethindrone / Q000008:administration & dosage / Q000009:adverse effects* / Q000031:analogs & derivatives; D000077563:Norethindrone Acetate; D015995:Prevalence; D045167:Progesterone Congeners / Q000008:administration & dosage / Q000009:adverse effects*; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D004338:Drug Combinations; D045166:Estradiol Congeners; D045167:Progesterone Congeners; D004958:Estradiol; D000077563:Norethindrone Acetate; D009640:Norethindrone