Meta-analysis of intrauterine device use and risk of endometrial cancer.
OBJECTIVE
We sought to study the association between intrauterine device (IUD) use and endometrial cancer.


METHODS
A comprehensive search of literature published through April 2007 was conducted, studies reviewed, and data abstracted. Data from ten studies were pooled and analyzed using both fixed- and random-effects models to examine the association of ever use of an IUD and endometrial cancer.


RESULTS
Based on the random effects model, a protective crude association between IUD use and endometrial cancer was observed (odds ratio [OR] = 0.39; 95% confidence interval [CI] = 0.29-0.51; heterogeneity p < 0.001) with a pooled adjusted risk of OR = 0.54 (95% CI, 0.47-0.63; heterogeneity p = 0.40). A decreased risk of endometrial cancer also was seen for increased years of IUD use (OR for 5 years of use 0.88; 95% CI = 0.84-0.92; n = 5; heterogeneity p = 0.14), increased years since last IUD use (OR for 5 years of use 0.91; 95% CI, 0.86-0.95; n = 4; heterogeneity p = 0.02), and increased years since first IUD use (OR for 5 years of use 0.89; 95% CI, 0.83-0.95; n = 4; heterogeneity p = 0.04).


CONCLUSIONS
Our results suggest that nonhormonal IUD use may be associated with a decreased risk for endometrial cancer; however, the exact mechanism for this association is unclear. Future investigations should address the difference in the proposed association by specific type of IUDs.
Beining
Robin M
RM
Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA 52242, USA.
Dennis
Leslie K
LK
Smith
Elaine M
EM
Dokras
Anuja
A
D000328:Adult; D000368:Aged; D016889:Endometrial Neoplasms / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007434:Intrauterine Devices / Q000706:statistics & numerical data*; D008875:Middle Aged; D012307:Risk Factors