title: Menopausal hormone therapy and risks of melanoma and nonmelanoma skin cancers: women's health initiative randomized trials.
abstract: BACKGROUND
  Case-control studies have reported that exogenous estrogen use is associated with increased risk of skin cancer. The effects of menopausal hormone therapy on incidence of nonmelanoma skin cancer and melanoma were evaluated in post hoc analyses of the Women's Health Initiative randomized placebo-controlled hormone therapy trials of combined estrogen plus progestin (E + P) and estrogen only (E-alone).
  
  
  METHODS
  Postmenopausal women aged 50-79 years were randomly assigned to conjugated equine estrogen (0.625 mg/d) plus medroxyprogesterone acetate (2.5 mg/d) or placebo in the E + P trial if they had an intact uterus (N = 16,608) or to conjugated equine estrogen alone or placebo in the E-alone trial if they had a hysterectomy (N = 10,739); the mean follow-up was 5.6 and 7.1 years, respectively. Incident nonmelanoma skin cancers (n = 980 [E + P trial]; n = 820 [E-alone trial]) and melanomas (n = 57 [E + P trial]; n =38 [E-alone trial]) were ascertained by self-report. Incident cases of cutaneous malignant melanoma were confirmed by physician review of medical records. Incidences of nonmelanoma skin cancer and melanoma were compared between the two randomization groups within each trial using hazard ratios (HRs), with corresponding 95% confidence intervals (CIs) and Wald statistic P values from Cox proportional hazards models. All statistical tests were two-sided.
  
  
  RESULTS
  Rates of incident nonmelanoma skin cancer and melanoma were similar between the active hormone (combined analysis of E + P and E-alone) and placebo groups (nonmelanoma skin cancer: HR = 0.98, 95% CI = 0.89 to 1.07; melanoma: HR = 0.92, 95% CI = 0.61 to 1.37). Results were similar for the E + P and E-alone trials when analyzed individually.
  
  
  CONCLUSIONS
  Menopausal hormone therapy did not affect overall incidence of nonmelanoma skin cancer or melanoma. These findings do not support a role of menopausal estrogen, with or without progestin, in the development of skin cancer in postmenopausal women.
authors: Department of Dermatology, Stanford University School of Medicine, 450 Broadway, Pavilion C, MC 5334, Redwood City, CA 94305, USA. tangy@stanford.edu
authors: Jean Y
authors: JY
authors: Tang
authors: Katrina M
authors: KM
authors: Spaunhurst
authors: Rowan T
authors: RT
authors: Chlebowski
authors: Jean
authors: J
authors: Wactawski-Wende
authors: Elizabeth
authors: E
authors: Keiser
authors: Fridtjof
authors: F
authors: Thomas
authors: Matthew L
authors: ML
authors: Anderson
authors: Nathalie C
authors: NC
authors: Zeitouni
authors: Joseph C
authors: JC
authors: Larson
authors: Marcia L
authors: ML
authors: Stefanick
mesh_terms: D000368:Aged; D015986:Confounding Factors, Epidemiologic; D015914:Estrogen Replacement Therapy / Q000009:adverse effects* / Q000379:methods; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage / Q000009:adverse effects*; D008545:Melanoma / Q000139:chemically induced / Q000453:epidemiology*; D008593:Menopause; D008875:Middle Aged; D016017:Odds Ratio; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D012878:Skin Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D016387:Women's Health
chemical_list: D004966:Estrogens, Conjugated (USP); D017258:Medroxyprogesterone Acetate