Meta-Analysis of Intrauterine Device Use and Risk of Endometrial Cancer

PurposeWe sought to study the association between intrauterine device (IUD) use and endometrial cancer.MethodsA 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.ResultsBased 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).ConclusionsOur 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.