Mailed self-sampling kits that test for HPV—the virus that can cause cervical cancer—helped significantly more women get screened for the cancer.

As reported in JAMA Network Open, researchers randomized women who had not had a screening for cervical cancer in more than three years into two groups. They mailed roughly half 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 get a screening in a clinical setting.

Within the cohort of underscreened women in the self-testing arm of the study, 26% completed a screening 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,” says lead author Rachel Winer, professor of epidemiology at the University of Washington 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 US trial to study the impact of mailed kits in a real-world health system setting.”

World Age-Standardized Incidence and Mortality Rates per 100,000 Population, Females, World Regions
World Age-Standardized Incidence and Mortality Rates per 100,000 Population, Females, World Regions
Image: World Bank

At-home HPV test

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 screen, the researchers say.

“We found that mailing unsolicited self-collection kits for HPV testing increased cervical cancer screening by 50% in women who were underscreened for cervical cancer, and that’s a particularly hard population to reach,” says coauthor 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 says. “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.”

Not following up on cervical cancer screening

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, the researchers note, 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 says, “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 say, 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 US is changing, and there is a real opportunity to expand options and improve the screening process for women,” Winer says. “I’m hopeful that a few years down the line, home-based screening will become routinely available.”

Additional coauthors are from the University of Washington; the University of Texas Southwestern Medical Center; University of California, Davis; and Kaiser Permanente Washington Health Research Institute; The National Cancer Institute of the National Institutes of Health funded the work.