By Jake Ellison, University of Washington
Signaling a potential major change in cervical cancer screening options for American women, a new study found that mailed self-sampling kits that test for HPV — the virus that can cause cervical cancer — helped significantly more women get screened for the cancer.
Half of the 12,000 cervical cancers diagnosed annually occur in women who have gone longer than three years without a screening, according to previous studies. That makes these women a high-priority population to get screened, the researchers said.
The study involving nearly 20,000 women was conducted by researchers from the University of Washington and Kaiser Permanente Washington Health Research Institute and was published Nov. 6 in JAMA Network Open.
In the study, women within the Kaiser Permanente Washington system who hadn’t been screened for cervical cancer in more than three years were randomized into two groups: Roughly half were mailed an HPV self-sampling kit that they could complete as an alternative to Pap screening, and the other half received only the standard care reminders to be screened in a clinical setting.
Within the cohort of underscreened women in the self-testing arm of the study, 26% were screened for cervical cancer versus 17% of underscreened women who received the standard reminders.
Of those underscreened women who returned the kits, 88% tested negative for the virus, signaling low risk for cervical cancer.
“Many studies have shown that an HPV test on a sample that a woman collects for herself performs as well as an HPV test done on a physician-collected sample,” said lead author Rachel Winer, professor of epidemiology at the UW School of Public Health and affiliate investigator at Kaiser Permanente Washington Health Research Institute.
“Randomized trials in other countries have shown that offering home-based HPV testing increases screening participation, but this was the first U.S. trial to study the impact of mailed kits in a real-world health system setting,” Winer said.
“We found that mailing unsolicited self-collection kits for HPV testing increased cervical cancer screening by 50 percent in women who were underscreened for cervical cancer, and that’s a particularly hard population to reach,” said co-author Diana Buist, senior investigator and director of research and strategic partnerships at Kaiser Permanente Washington Health Research Institute.
“So, it’s a good news story,” Buist said. “And now that HPV-only testing is a recognized screening strategy in the United States, it really opens up the possibility for home testing to be a widespread option for women.”
Researchers also wanted to find out whether this high-priority population of women would perform the self-sampling and then, if the sample tested positive for HPV, go in for a follow-up test to determine the presence of precancerous cervical cells that could be treated to prevent cancer.
Unfortunately, they noted, while the vast majority of women tested negative for the virus, not all of the participants who tested positive followed up.
“It’s great that 88% of women who self-sample at home would not need to come into the clinic,” Winer said, “but there’s a key 12% in our trial that were identified to be at increased risk for cervical cancer — and yet only 70% of those women came in for follow-up testing.”
Consequently, the researchers said, additional implementation efforts need to strategize how to increase use of the kit and in-clinic follow-up for positive results to maximize detection and treatment of pre-cancers in high-risk women.
“The landscape of cervical cancer screening in the U.S. is changing, and there is a real opportunity to expand options and improve the screening process for women,” Winer added. “I’m hopeful that a few years down the line, home-based screening will become routinely available.”
Co-authors include John Lin, research study coordinator at the UW Department of Epidemiology in the School of Public Health; Jasmin Tiro, associate professor at the University of Texas Southwestern Medical Center; Diana Miglioretti, senior investigator at Kaiser Permanente Washington Health Research Institute and professor at University of California, Davis; Tara Beatty, project manager at Kaiser Permanente Washington Health Research Institute; Hongyuan Gao, programmer at Kaiser Permanente Washington Health Research Institute; Kilian Kimbel, research specialist at Kaiser Permanente Washington Health Research Institute; and Chris Thayer, chief medical information officer at Kaiser Permanente Washington.
For an in-depth Q&A with study authors Rachel Winer and Diana Buist on how mailing home HPV tests may provide an alternative to Pap screening, go to Kaiser Permanente Washington Health Research Institute’s story.
This research was funded by the National Cancer Institute of the National Institutes of Health.