Self-collected menstrual blood samples offered "highly concordant" results with clinician-collected sampling in women who were positive for human papillomavirus (HPV), a researcher reported.
In a small study of about 100 women who tested positive for HPV or presented for regular screening, the concordance rates were 94% to 100% between self-collected menstrual-blood samples and clinician-collected samples, reported Sara Naseri, MD, of Stanford University in California, who is also of , the company that developed the device used to collect the menstrual blood.
Additionally, five study participants who were high-risk HPV-positive, and had high-grade cervical dysplasia, had 100% agreement between menstrual blood samples and physician-collected samples, she said in a presentation at the American College for Obstetricians and Gynecologists annual meeting, held in San Diego.
Overall, 94% of all study participants said that they would recommended menstrual blood self-collection over physician-performed tests as a non-invasive, "passive" way to collect HPV samples, Naseri's group found.
"Menstrual blood is a resource," said co-author Paul Blumenthal, MD, MPH, of the Stanford Program for International Reproductive Education and Services, adding that menstrual blood may prove useful for other non-invasive tests, such as measuring hemoglobin A1C or follicle-stimulating hormone.
"This is a potential tool," Blumenthal told MedPage Today. "It's not just a waste product."
Cervical cancer is one of the most common types of cancer diagnosed in women, and it is the second highest cause of cancer-related mortality, according to the authors. Currently, the American Cancer Society recommends screening for HPV in women 25 and older every 5 years using molecular testing, or cotesting every 3 years during a Pap test. The U.S. Preventive Services Task Force () calls for screening every 3 years with cervical cytology alone in women ages 21 to 65, or for women ages 30 to 65, every 5 years with high-risk HPV-positive testing either alone or in combination with cytology. The USPSTF recommendation is currently under review for an .
For the current study, menstrual blood samples were collected using Q-pad, a modified menstrual pad that has a removable testing strip.
Women who presented either for HPV screening or those with an HPV-positive history were eligible for the study. The investigators evaluated the concordance between three types of HPV samples: a sample collected by a clinician, a self-collected vaginal swab, and a Q-pad sample for use during the next menstrual cycle. All conventional samples were processed using the Roche Molecular System Cobas HPV test. Dried blood spots from the Q-pad samples were mixed with liquid and processed with the same test.
Approximately 150 women participated in the study, and 107 provided clinician-collected specimens and self-collected Q-pad samples. Participants had an average age of 32 and 80% were nulliparous. Around 30% of patients said they were uncomfortable with self-swabbing and did not provide a vaginal swab. Among patients who only provided Q-pad and clinician-collected samples, self-collected vaginal swabs were not evaluated as a collection method for HPV samples.
The authors reported that 12% of patients who were Q-pad HPV-positive were negative based on clinician-collected sampling, and suggested that the clinicians who collected the samples did not reach high enough into the cervical canal to obtain positive cells while menstrual blood flowed all the way through the cervix, leading to the discrepancy.
As this study took place during the start of the pandemic, some participants were unable to mail their Q-pad samples to the researchers in time, which resulted in loss to follow-up, Blumenthal said. Additionally, the machine that processed the samples was not optimized for the elution process of the dried menstrual blood, which was a technical limitation of this research.
Future studies should include a larger sample size in a more geographically diverse population and aim to test the sensitivity and specificity of the Q-pad test, Blumenthal added. He stated that using menstrual blood as a diagnostic tool is not only a potentially valuable window into several health conditions, but could also destigmatize the menstrual cycle.
"I think in some parts of the world, the U.S. included, there's still a lot of menstrual stigma," Blumenthal said. "By recognizing that menstrual flow is a valuable clinical resource, I think we could do a lot to reduce stigma."
Disclosures
A co-author disclosed a relationship with Quidel.
Primary Source
American College of Obstetricians and Gynecologists
Naseri S, et al "Screening for high risk human papillomavirus using passively self-collected menstrual blood" ACOG 2022; Abstract A91.