乌鸦传媒

Mailing at-home human papillomavirus (HPV) test kits to underscreened women failed to significantly increase the detection or treatment of cervical precancers compared with usual care, the randomized HOME trial found.

Among nearly 20,000 women with a lapse in screening, 12 of those randomized to receive at-home HPV test kits by mail were ultimately found to have cervical precancers compared with eight in the group who were sent reminders for in-clinic Papanicolaou screening, a non-significant difference (relative risk [RR] 1.49, 95% CI 0.61-3.64), reported Rachel Winer, PhD, MPH, of the University of Washington HPV Research Group in Seattle, and colleagues.

And no difference was seen for treatment of these precancers, all 12 in the intervention group versus seven in the usual care group (RR 1.70, 95% CI 0.67-4.32), they wrote in .

Nonetheless, the proportion of women screened was significantly higher for the at-home testing group -- 26.3% versus 17.4% with usual care (RR 1.51, 95% CI 1.43-1.60). Also, the at-home testing group had a significantly shorter time to screening (P<0.001).

From 2014 to 2016, Winer's group randomized 19,851 women ages 30 to 64 in the Kaiser Permanente Washington system without a history of a Pap test in nearly 3 and a half years to one of the two screening arms. Cervical precancer was defined as cervical intraepithelial neoplasia grade 2 (CIN2) or worse.

Winer told 乌鸦传媒 that not finding a difference in the precancers detected and treated was "more a function of study power than a failure of the trial," and the lack of study power could be explained by several factors.

First off, the overall uptake of the HPV test kits was lower than expected: only 12.1% of women (1,206 of 9,960) who were mailed the test used it compared with the assumption that 30% would. Meanwhile, the uptake of screening among the control group was higher than expected: 17.4% of women (1,719 of 9,891) who were invited for in-clinic screening went compared with the assumption that only 9% would.

In addition, the follow-up adherence was lower than expected, particularly for women who had a positive result from the at-home HPV test kit and therefore were recommended for colposcopy follow-up. For example, 41% of women who had a positive test result for HPV-16 or HPV-18 did not go in for follow-up. In a , Chailee Faythe Moss, MD, and colleagues from Johns Hopkins University in Baltimore, described this nonadherence to follow-up "especially concerning."

Several reasons may explain why only a fraction of the women completed the at-home tests, one being that the tests were part of a research study, not a standard-of-care recommendation that would negate the need for in-clinic follow-up. "Even though we were trying to mimic clinical practice as much as possible to see how this [would] roll out in a healthcare system, we still had to tell women that they had to come in for a Pap regardless of the results," said Winer.

In addition, although countries like the Netherlands and Australia mail out HPV tests as part of their national screening program, in the U.S. the concept of HPV self-testing is still new, she explained.

In August 2018, the U.S. Preventive Services Task Force (USPSTF) updated their recommendations, listing HPV testing alone every 5 years as one of three acceptable forms of primary cervical cancer screening in women ages 30 to 65. In addition, the recommendations mentioned HPV self-testing as a potential strategy for increasing screening rates, but noted that "rigorous comparative studies" were still needed.

"We know from other research that an HPV test on a self-collected sample performs with similar accuracy to an HPV test on a clinician-collected sample," said Winer. "You should be able to apply the primary HPV screening to a self-collected sample -- it is just not being done in the U.S. yet."

According to Moss's group, given that the FDA has not approved vaginal HPV testing for risk stratification in cervical cancer screening, patients may have been "wary" of home screening, another reason for low uptake.

An aspect of the study that may limit the applicability of the findings was that although the target population for the trial was underscreened women who were identified as overdue for a Pap test, non-English speaking women were ineligible because at-home test kit materials were available only in English. According to Winer, this decision was due to a lack of resources to translate the materials into other languages.

A second trial is now underway by Winer and colleagues, with enrollment planned to begin in early 2020 at Kaiser Permanente Washington. The trial will evaluate at-home HPV testing in not only underscreened women but also women adherent to screening. According to Winer, the trial will also evaluate the cost-effectiveness of tests and look at ways to improve initial uptake of the tests and adherence to follow-up.