Oral contraceptive and IUD use and endometrial cancer: A population-based case–control study in Shanghai, China
Article first published online: 5 JUL 2006
Copyright © 2006 Wiley-Liss, Inc.
International Journal of Cancer
Volume 119, Issue 9, pages 2142–2147, 1 November 2006
How to Cite
Tao, M. H., Xu, W. H., Zheng, W., Zhang, Z.-F., Gao, Y.-T., Ruan, Z. X., Cheng, J. R., Gao, J., Xiang, Y. B. and Shu, X. O. (2006), Oral contraceptive and IUD use and endometrial cancer: A population-based case–control study in Shanghai, China. Int. J. Cancer, 119: 2142–2147. doi: 10.1002/ijc.22081
- Issue published online: 31 AUG 2006
- Article first published online: 5 JUL 2006
- Manuscript Accepted: 10 APR 2006
- Manuscript Received: 28 DEC 2005
- National Cancer Institute, United States Public Health Service (USPHS). Grant Number: R01CA92585
- oral contraceptives (OCs);
- intrauterine device (IUD);
- endometrial cancer
Oral contraceptive (OC) and intrauterine device (IUD) use have been shown to be protective factors for endometrial cancer in several epidemiological studies; however, few studies have been conducted in Chinese populations. We evaluated the association between OC and IUD use and endometrial cancer risk in a population-based case–control study among Chinese women in Shanghai, China. The study included 1,204 newly diagnosed endometrial cancer cases and 1,212 age frequency-matched healthy controls. Logistic regression models were used to estimate adjusted odds ratios (OR) and their 95% confidence intervals (95% CI). In our study population, 18.5% cases and 24.9% controls reported having ever used OCs with an OR of 0.75 (95% CI, 0.60–0.93), after adjusting for known risk or protective factors for endometrial cancer. The risk of endometrial cancer decreased with long-term use of OCs with the OR for more than 72 months of use being 0.50 (95% CI, 0.30–0.85). The effect of OC use remained 25 or more years after cessation of use; the associated OR was 0.57 (95% CI = 0.42–0.78) as compared to nonusers. Similarly, fewer cases than controls had ever used IUD, with the multivariable adjusted OR being 0.53 (95% CI = 0.43–0.65). A reduction in risk was observed regardless the duration of use or age at first and last use. These results suggest that OC and IUD use may confer long-term protection against endometrial cancer. © 2006 Wiley-Liss, Inc.