title: Hormone replacement therapy and endometrial cancer in Ontario, Canada.
abstract: Estrogen therapy reduces the risk of osteoporosis and cardiovascular diseases but is associated with an increased risk of endometrial cancer. We have assessed the impact of a regimen of estrogen with progestogen on risk of endometrial cancer for women 48 years and older. We conducted a case-control study in Ontario, Canada, from 1994 to 1998 by interviewing registry-based cases (n = 512) and population controls (n = 513) to obtain information on use of hormones and dietary habits. Compared to non-users, the use of opposed hormone therapy in sequential regimen for more than three years showed a borderline increase in risk (OR = 1.49, 95% CI 0.93-2. 40), but this increase was much less than among women on unopposed estrogen (OR = 4.12, 95% CI 2.21-7.71). Stronger associations were observed when duration of sequential hormone use was examined as a continuous variable (OR per three years of use = 1.21, 95% CI 1.03-1. 42). The effect of opposed hormone therapy on endometrial cancer risk appears to vary both by usage patterns and by patient characteristics of body weight and history of diabetes.
authors.affiliation: Department of Public Health Sciences, University of Toronto, 308-12 Queen's Park Crescent West, Toronto, Ontario, Canada. meera.jain@utoronto.ca
authors.forename: M G
authors.initials: MG
authors.lastname: Jain
authors.forename: T E
authors.initials: TE
authors.lastname: Rohan
authors.forename: G R
authors.initials: GR
authors.lastname: Howe
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D016001:Confidence Intervals; D016889:Endometrial Neoplasms / Q000139:chemically induced* / Q000453:epidemiology / Q000473:pathology; D005260:Female; D020249:Hormone Replacement Therapy / Q000009:adverse effects* / Q000706:statistics & numerical data; D006801:Humans; D007407:Interviews as Topic / Q000379:methods; D016015:Logistic Models; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D009864:Ontario / Q000453:epidemiology; D012307:Risk Factors; D011795:Surveys and Questionnaires