Use of intrauterine devices may reduce cervical cancer risk
The use of an intrauterine device appeared associated with a significant decrease in invasive cervical cancer incidence, according to study findings.
“The pattern we found was stunning. It was not subtle at all,” Victoria K. Cortessis, PhD, associate professor of clinical preventive medicine at Keck School of Medicine at University of Southern California, said in a press release. “This finding could potentially benefit women with limited access to health care screening who reside in areas of high cervical cancer incidence.”
Cortessis and colleagues conducted a systematic review and meta-analysis to assess the effect of intrauterine device (IUD) use on cervical cancer incidence among more than 12,000 women included in 16 previously published studies that examined individual-level measures of IUD use and cervical cancer incidence.
The researchers observed a 30% decrease in cervical cancer risk among women who reported IUD use compared with women who reported no IUD use (summary OR = 0.64; 95% CI, 0.53-0.77).
“The possibility that a woman could experience some help with cancer control at the same time she is making contraception decisions could potentially be very, very impactful,” Cortessis said in the release.
HemOnc Today spoke with Cortessis about the magnitude of benefit observed, the potential impact these findings could have on cervical cancer prevention, and whether gynecologists should discuss IUD use with their patients as a potential cervical cancer prevention technique.
Question: What prompted this study?
Answer: There is an urgent need for methods of cervical cancer control that can be widely used in low-resource settings. This motivates me to look for emerging research findings that might suggest novel approaches, and the IUD came to my attention some time ago. It was only in recent years that — upon completion of a series of studies sponsored by International Agency for Research on Cancer — a body of data on this topic that warranted quantitative synthesis became available. We conducted the meta-analysis to evaluate the existing evidence base on this question as a cohesive whole.
Q: How did you conduct the study?
A: We looked at registries, dissertations and meeting proceedings, and we thoroughly searched those types of outlets. We also searched through ‘gray literature’ and identified hundreds of articles on this topic. We reviewed these to identify the comparatively small set of reports on high-quality epidemiologic studies and extracted data. We then implemented a meta-analysis to quantitatively synthesize the published data.
Q: What did you find?
A: We found a history of IUD use appeared associated with remarkably less cervical cancer. Of note, we limited the disease status for our study to newly diagnosed cervical cancer. Results of the meta-analysis showed that women who had ever used an IUD experienced 30% less incidence of cervical cancer.
Q: Can you provide context for the magnitude of benefit observed?
A: If our results represent a true preventive process, we are looking at the possibility that one-third of women who would otherwise get cervical cancer could be spared if they used an IUD. There are some provisos that come with this, and we conducted numerous supplementary analyses to understand the data in more detail. There was some variation in results between studies, and the supplementary analyses accord with the possibility that the IUD may be more helpful in areas where women do not have access to regular screening services and areas with evidence of higher HPV incidence.
Q: What should future research entail?
A: There is a great deal of follow-up work to be done. Our hope is that — if this turns out to be a real preventive measure — the impact could be particularly great in the developing world, where cervical cancer is becoming ever more common because of the types of secondary preventive services that are not readily available in those settings.
Q: Should gynecologists begin discussing IUD use with their patients as a potential cervical cancer prevention technique?
A: Gynecologists who discuss contraceptive options with patients should state that there are pros and cons to every device. These results could be mentioned in that kind of counseling discussion, with clear indication that — at this point — the data are an observation. More research is needed before we can conclude that the IUD offers this kind of protection. Another limitation to our work is that most of the studies we analyzed were conducted during a time when hormonal devices were not readily available. We do not really know if we will see similar inverse associations with the use of hormonal devices. Also, we could not delve into whether duration of use of the device affected outcomes. These are topics of new research. We are in the very early pilot stages of trying to obtain funding for these projects. Our hope is that other teams will conduct research on this, as well, so we can all learn within the next few years what the promise of this approach might be.
Q: Is there anything else that you would like to mention?
A: Part of the plausibility of this scenario is that the contraceptive mechanism of the IUD is likely to involve inflammation and, in some instances, an immune response. There are two reasons to discuss this. First, unfortunately, there are many myths present in our society concerning how the IUD works. The other is plausibility that an inflammatory or immune response may prevent cervical cancer by helping to clear persistent HPV infections now believed to precede cervical cancer. – by Jennifer Southall
Cortessis VK, et al. Obstet Gynecol. 2017;doi:10.1097/AOG.0000000000002307.
For more information:
Victoria K. Cortessis, PhD, can be reached at University of Southern California, 1441 Eastlake Ave., MC-9175, Los Angeles, CA 90089; email: firstname.lastname@example.org.
Disclosure: Cortessis reports no relevant financial disclosures.