title: Case-control study of postmenopausal hormone replacement therapy and endometrial cancer.
abstract: This study evaluated recent inconsistent findings that adding progestins to postmenopausal estrogen replacement therapy protects against endometrial cancer. Using a population-based case-control study, the authors compared 511 endometrial cancer cases aged 50-79 years in the Philadelphia, Pennsylvania, region during 1999-2002 with 1,412 random-digit-dialing controls regarding postmenopausal hormone replacement therapy (HRT) use. Telephone interviews were performed with memory aids mailed in advance. An increased risk of endometrial cancer was observed among postmenopausal women using only unopposed estrogen for 3 or more years, compared with women who never used HRT (adjusted odds ratio = 3.4, 95% confidence interval (CI): 1.4, 8.3). Using combination HRT (of any duration) was associated with a substantial reduction in risk (odds ratio = 0.8, 95% CI: 0.6, 1.1). Comparing women using only combined estrogen and progestin for 3 or more years with women using only unopposed estrogen for 3 or more years, the authors found that the adjusted odds ratio was 0.2 (95% CI: 0.1, 0.6). Long-term use of unopposed estrogen is associated with increased risk for endometrial cancer, whereas combined estrogen plus progestin hormone therapy is not. Thus, if HRT is to be used in women with an intact uterus, this study confirms the benefit of adding progestins to the regimen.
authors.affiliation: Department of Medicine, School of Medicine, University of Pennsylvania, Philadelphia, 19104-6021, USA. bstrom@cceb.med.upenn.edu
authors.forename: Brian L
authors.initials: BL
authors.lastname: Strom
authors.forename: Rita
authors.initials: R
authors.lastname: Schinnar
authors.forename: Anita L
authors.initials: AL
authors.lastname: Weber
authors.forename: Greta
authors.initials: G
authors.lastname: Bunin
authors.forename: Jesse A
authors.initials: JA
authors.lastname: Berlin
authors.forename: Mona
authors.initials: M
authors.lastname: Baumgarten
authors.forename: Angela
authors.initials: A
authors.lastname: DeMichele
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Rubin
authors.forename: Michelle
authors.initials: M
authors.lastname: Berlin
authors.forename: Andrea B
authors.initials: AB
authors.lastname: Troxel
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Rebbeck
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D015986:Confounding Factors, Epidemiologic; D016889:Endometrial Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D007407:Interviews as Topic; D016015:Logistic Models; D008875:Middle Aged; D015143:Philadelphia / Q000453:epidemiology; D017698:Postmenopause; D011372:Progestins / Q000008:administration & dosage*; D012307:Risk Factors
chemical_list: D011372:Progestins