INTRAUTERINE-DEVICE USE AND ENDOMETRIAL CANCER RISK

Background. Because intrauterine devices (IUD) invoke acute and chroni c inflammatory responses in the endometrium, it is possible that prolo nged insertion of an IUD could induce endometrial cancer, Methods. We examined the relation between use of an IUD and endometrial cancer ris k using data from a multicentre case-control study involving 405 endom etrial cancer cases and 297 population controls. Results. A total of 2 0 (4.9%) cases and 34 (11.4%) controls reported any use of an IUD. Aft er adjustment for potential confounders, IUD use was not associated wi th an increased risk of endometrial cancer (RR = 0.56 for ever use; 95 % CI : 0.3-1.0), Little reduction in risk was observed among women who last used an IUD within 10 years of the index date (RR = 0.84; 95% CI :0.3-2.4) but risk was decreased among women who used an IUD in the mo re distant past (RR = 0.45; 95% CI :0.2-1.0). Risk did not vary consis tently with number of years of IUD use or with years since first use. Risk was not increased among women who used inert devices (RR = 0.46; 95% CI :0.3-3.6) or those who used devices containing copper (RR = 1.0 8; 95% CI :0.1-3.6). Conclusion. These data are reassuring in that the y do not provide any evidence of an increased risk of endometrial canc er among women who have used IUD.