Association of cervical cancer and intrauterine device use: a narrative review

Although intrauterine devices (IUDs) are widely used as a contraceptive method, their association with cervical intraepithelial neoplasia remains a subject of debate. Some studies suggest a potential protective effect, possibly through local immune modulation, while others report no significant association. Evidence, however, remains scarce and inconsistent, particularly regarding long-term IUDs use. Our study aims to address these gaps by exploring the relationship between IUDs use and cervical cancer within the broader context of cervical cancer prevention. We conducted a narrative review by searching the PubMed, Scopus, LILACS, and Cochrane databases, utilizing a combination of text and Medical Subject Headings (MeSH) terms. The search terms included "intrauterine contraception," "intrauterine devices," "hormonal intrauterine device," "IUD," "LNG-IUS" (levonorgestrel intrauterine system), and "cervical cancer," "cervical lesions," and "cervical cancer risk," for publications available up to July 2024. Our review included 16 studies of fair to good quality, employing rigorous methodologies and addressing key confounding variables to evaluate the association between IUDs use and the risk of cervical cancer. Among these, eight studies reported that IUD use was associated with a lower risk of cervical cancer, while six studies identified a trend toward reduced risk, although without significant differences. Conversely, two studies found an association between IUD use and a higher risk of cervical cancer. A critical limitation in many of these studies was the lack of information regarding the specific type of IUD used by the study populations. These findings underscore the need for further research to clarify the association between IUDs use and cervical cancer risk, with a focus on long-term outcomes and stratification by IUD type.