Estrogen replacement therapy and ovarian cancer.
BACKGROUND
A recent meta-analysis concluded that there was no overall association between estrogen replacement therapy (ERT) and risk of epithelial ovarian cancer. However, several subsequent studies have suggested that long-term ERT could increase ovarian cancer risk.


METHODS
We prospectively examined the association of ERT with epithelial ovarian cancer among 31,381 postmenopausal women in Iowa followed for 15 years.


RESULTS
Women who were using ERT at baseline had an elevated multivariate-adjusted relative risk of ovarian cancer (1.7; 95% confidence interval [CI] = 1.1-2.8) compared with never-users. Risk was higher among women who had been using ERT at baseline for more than 5 years (2.5; CI = 1.4-4.5). A time-dependent analysis likewise yielded a relative risk of 1.7 for current ERT use. Former ERT use was not associated with ovarian cancer incidence.


CONCLUSIONS
Long duration of ERT use after menopause could increase the risk of epithelial ovarian cancer.
Folsom
Aaron R
AR
Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis, Minnesota55454-1015, USA. folsom@epi.umn.edu
Anderson
Jeffrey P
JP
Ross
Julie A
JA
D000368:Aged; D004334:Drug Administration Schedule; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D016017:Odds Ratio; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D017698:Postmenopause; D011446:Prospective Studies; D018570:Risk Assessment