A new study finds that mailing self-collection kits to test for high-risk human papillomavirus (HPV) infection has the potential to boost cervical cancer screening – especially for low-income women who are overdue for testing.
Researchers at the University of North Carolina Gillings School of Global Public Health and UNC Lineberger Comprehensive Cancer Center are authors of the study, published online Nov. 5 in the journal Obstetrics & Gynecology.
The study involved mailing at-home, HPV self-collection kits to 193 low-income women in North Carolina who, according to national guidelines, were overdue for screening. The researchers reported that the screening approach detected high-risk HPV in all cases in which women were found to have high-grade, abnormal cervical precancerous growths, showing that self-collection at home for HPV may be a viable method to identify women at high risk for cervical cancer.
“This is a demonstration that mailing self-collection kits and returning them to test for high-risk HPV infection has big potential to increase screening access among underscreened women, and can do that successfully,” said Dr. Jennifer Smith, professor of epidemiology at the UNC Gillings School of Global Public Health, member of UNC Lineberger and the study’s senior author.
Although cervical cancer is preventable through early detection and treatment, the American Cancer Society estimates that more than 4,100 women will die from cervical cancer in the United States this year. National surveys have shown that nearly 20 percent of women in the United States who are eligible for cervical cancer screening report they have not been tested for cervical cancer within the recommended time interval.
“Women are dying unnecessarily of cervical cancer because they either haven’t been vaccinated against HPV in adolescence, or they have not been getting screened according to national guidelines,” Dr. Smith said. “Increasing screening rates among underscreened women is of paramount importance.”
In 2014, the U.S. Food and Drug Administration signed off on using an HPV test to screen for cervical cancer for women 25 years and older, in conjunction with the Pap test. Earlier this year, the U.S. Preventive Services Task Force gave an “A” rating to HPV primary screening alone for women ages 30 to 65.
“There are many barriers that cause women to be underscreened,” said the study’s first author Ms. Andrea Des Marais, project manager in epidemiology at the Gillings School. “HPV tests are being widely used now in the United States, but only through physician collection in clinical practice, which requires that women come to a clinic. Offering HPV testing using self-collection by mail has potential to reach women who are at highest risk for not being screened – those who don’t access regular medical care.”
For the study, researchers mailed at-home, self-collection kits to low-income women in North Carolina who were overdue for screening. They included women between the ages of 30 and 64 years who had reported no history of receiving a Pap test, which checks for precancerous or cancerous cells, within the past four years.
Researchers provided study participants with self-collection brushes along with instructions for taking a sample from inside the vagina. The brush samples then were tested in a lab for HPV and other sexually transmitted infections. Participants also self-collected samples at a clinic and handed them to a nurse, and had a pelvic exam for a clinician to collect a Pap smear sample.
The researchers compared the results from self- and clinician-gathered samples – which were tested for high-risk HPV strains linked to cervical cancer – to the Pap results and the results of cervical biopsies collected during colposcopy, a secondary diagnostic test that confirms the presence of cervical precancerous lesions among women with abnormal Pap smear results.
The home self-collection test indicated that 12.4 percent of women were infected with high-risk HPV, the self-collection tests used in the clinic found 15.5 of the women had high-risk HPV infection, and the clinician-collected test identified 11.4 percent of the women had high-risk HPV infection.
“We found comparable detection between self-collection and physician collection,” Ms. Des Marais said.
All women found to have high-grade cervical lesions by Pap smear or by cervical biopsy were positive for high-risk HPV on their at-home self-collected sample.
“In this sample, we found that all women who had high-grade lesions had HPV-positive at-home self-collection results,” Dr. Smith said. “We didn’t miss any of those high-grade cases by conducting home self-collection.”
Dr. Smith said more work must be done, such as identifying ways to make the self-collection process more efficient and cost-effective – and getting FDA approval for the clinical use of self-collection for cervical cancer screening.
“This is a proof-in-principle study that we used to determine whether home self-collection is highly effective for detecting high-grade disease,” Dr. Smith said. “We already are working on the next step, a clinical trial in which women who aren’t up-to-date on screening receive either a referral to a free clinic appointment to receive a screening, or a self-collection kit in the mail, followed by referral to a free clinic appointment. This will allow us to determine the effect of self-collection on screening uptake.”
Photo: Ms. Andrea Des Marais (left) and Dr. Jennifer Smith