December 3, 2018

Cervical cancer screening study explores home-based options


Could at-home kits help save more lives? Drs. Diana Buist and Rachel Winer are on a journey to find out.

By Diana Buist, PhD, senior investigator and director of research and strategic partnerships at Kaiser Permanente Washington Health Research Institute (KPWHRI), and Rachel Winer, PhD, associate professor of epidemiology at the University of Washington School of Public Health and affiliate investigator at KPWHRI

Scientific breakthroughs in cancer screening have saved countless lives over the past several decades. But sometimes the biggest barrier to effective cancer screening isn’t science — it’s what people have to do to get screened.

Take cervical cancer screening, for example. Nearly all cervical cancers can be prevented by identifying and removing precancers caused by certain strains of the human papillomavirus (HPV). But despite the success of Pap screening at reducing deaths from cervical cancer — a drop of more than 50% in the last 40 years — screening rates are actually declining across the United States.

Many women find Pap screening uncomfortable, embarrassing, and difficult to make time for — all of which likely contribute to the decline. Could we reverse this trend — and save more lives — by offering women an easier option for screening?

Our research team from Kaiser Permanente Washington Health Research Institute, the University of Washington, the University of Texas Southwestern, and the University of California, Davis is on a journey to find out. And what we’re learning so far could change the landscape of cervical cancer screening for women everywhere.

What if cervical cancer screening could happen at home?

Most people have heard about at-home test kits for colorectal cancer screening — also known as “FIT” tests. Research at Kaiser Permanente Washington and elsewhere has shown that mailing these kits was an effective — and cost-effective — way to boost colorectal cancer screening rates among people overdue for screening.

Our research team set out to explore the promise of at-home kits to test for HPV as an effective way to increase screening for cervical cancer. The kit works by taking a sample swab of vaginal cells collected at home and sending it to the lab to be tested for the HPV strains mostly likely to cause cervical cancer. Research by our team and others has shown that samples collected at home work just as well to detect HPV as samples collected in the clinic.

And most recently, in our “Home-based Options to Make cervical cancer screening Easy” (HOME) study, we looked at what happened when Kaiser Permanente Washington mailed HPV testing kits to a sample of women who were overdue for cervical cancer screening. To date, HOME is the first and only randomized trial to study mailed HPV test kits in a real-world health system. Here’s how it worked:

· The study included 16,590 women aged 30–65 who were enrolled at Kaiser Permanente Washington (then Group Health) for at least 3 ½ years and had not had a Pap smear in that time.

· We divided these women into two groups at random. One group received usual care (annual reminders to attend in-clinic screening). The other group received usual care plus a mailed HPV test kit, instructions on how to complete the test, and a pre-paid envelope for returning it to the Kaiser Permanente Washington lab.

· Kaiser Permanente primary care providers managed test results that required in-clinic follow-up.

· After 6 months, we used electronic health records to see how many women in each group had received cervical cancer screening, either in the clinic or at home.

Results of the HOME study

Like randomized trials done in other countries, we found that mailing HPV kits increased screening by more than 50% compared to usual care alone. We also used a follow-up survey to look at the reasons why women decided to complete (or not to complete) the HPV test kit.

We learned that women who returned the kits found them convenient and easy to use. They were also highly positive about the experience, suggesting that mailing HPV kits can help address known barriers to in-clinic Pap screening.

Among women who did not return the kit, the most common reason they cited for not completing the test was feeling unsure about how to use the kit correctly. This echoes findings from other studies in different settings.

We also interviewed 46 women to understand their experiences after a they got a positive HPV test result following their home test. The Journal of Women’s Health published our results online last week: “Understanding Patients’ Perspectives and Information Needs Following a Positive Home Human Papillomavirus Self-Sampling Kit Result.”

Although most women we interviewed liked the kit’s convenience, some raised concerns about test results from the at-home sample that did not match subsequent in-clinic Pap test results. This led them to question the accuracy of HPV home testing.

What many women don’t know, however, is that there are valid reasons why the test results might differ. Because HPV is a virus that can come and go (meaning your body clears the virus), it might be present at the time of one test and gone at another time. Importantly, these findings illustrate the need for better education and communication around HPV test results.

What’s next?

We still have a lot to learn about what health systems can do to improve cervical cancer screening. To that end, our team recently applied for a new grant from the National Cancer Institute to test different options for cervical cancer screening among all women at Kaiser Permanente Washington. If funded, the grant will allow us to evaluate screening participation, cost-effectiveness, and patient and provider experience.

In the meantime, we hope sharing what we’ve learned so far will help shift how women, providers, and health systems think about cervical cancer screening. The possibility of getting screened via home HPV testing could give women an important choice they’ve never had before. For some, it could be a choice that saves their lives. But it’s a choice that needs to come with the right amount of information at the right time.

The HOME study taught us that future outreach efforts should do a better job of explaining the home HPV kit — how it works, how you complete the test, and what the results mean. Understanding the best ways to communicate with women about HPV home testing will help us anticipate their future needs as the landscape of cervical cancer screening changes. And as more options for screening become available, we’ll be better prepared to help women everywhere make the choice that’s right for them.

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