New HPV test crucial step for eradicating cervical cancer
Friday, 23 June 2023 (11:27 IST)
A new affordable, point-of-care test has been developed that can detect evidence of human papillomavirus (HPV) — a leading cause of cervical cancer.
Cervical cancer is almost always caused by an infection with certain strains of HPV. But high medical costs and infrastructure barriers have prevented wider access to screening and treatments.
A new study, published on Wednesday in the journal Science Translational Medicine,shows how the HPV test can be performed in 45 minutes and will cost as little as $5 (€4.6) per test.
The test's ease of use and low cost could enable it to fill critical gaps in cervical cancer screening in developing countries, where HPV infections often go undetected.
Cervical cancer is not being prevented
Cervical cancer is a story of the success and failure of science. It is one of the most preventable forms of cancer, yet 600,000 women a year are diagnosed with cervical cancer, while 350,000 women a year die of the disease. According to the World Health Organization (WHO), 90% of these women live in lower-income countries.
We currently have a range of tools to treat and prevent HPV — vaccines to stop HPV infections, highly accurate ways to detect HPV, and early treatments like freezing or laser treatments for HPV warts. But the cost and infrastructure required for HPV screening is one of the major barriers to reducing cervical cancer rates.
"We haven't done a good job of rolling out vaccines, or high performance testing and screening. The WHO set a goal of 90% of girls being vaccinated, 70% of women being screened at age 30 and 45, and 90% of women being treated. We're really far from delivering on that goal," said Rebecca Richards-Kortum, a professor of bioengineering at Rice University in the US, and author of the study, who also worked on the new HPV test.
Current HPV tests like the GeneXpert® system has a subsidised price of $15 per test, but the system to run the test costs $17,000. Then there's the laboratory costs and training required to perform the tests.
"You need laboratories with power, air-conditioning, and internet. A lot of places in the world delivering medical care don't have those things," Richards-Kortum told DW.
Same-day HPV screening and treatment
What the authors of the study set out to do was create a HPV test that is less expensive and can be performed during one healthcare appointment.
"Women can self-collect a sample, which is then immediately tested [in 45 minutes]. Then if the test is positive, they can be immediately treated, all in a single visit," said Richards-Kortum.
The benefit is that the test is simple to perform without much laboratory training and doesn't require expensive equipment and laboratory equipment. The authors estimate it will cost $5 per test, with an instrument cost of $1,000, but with much less training required.
The test itself identifies traces of HPV DNA in a sample from cervicovaginal swabs. It works similarly to a COVID-19 lateral flow test, but with a few extra steps at the beginning. DNA is extracted from cells in the sample using chemical buffers, followed by heat-treatment and amplification steps, then the solution is placed onto a lateral flow strip to be read just like a COVID-19 test.
In trial runs, the test detected HPV DNA in provider-collected cervicovaginal swabs from the US, as well as self-collected swabs from a hospital in Mozambique.
Right now, the test can only detect two of the HPV strains that can cause cervical cancer — HPV16 and HPV18.
These two strains account for 70% of all cervical cancers, but Richards-Kortum and her team want to expand the test to detect the other six high-risk HPV strains.
HPV screening with low-resource requirements
Countries like Rwanda already have very strong HPV vaccination and screening programmes. The country could be the first in Africa, possibly even the world, to eliminate the disease.
Other countries with high cervical cancer rates and barriers to HPV screening and vaccinations could learn from Rwanda. The hope is that the new test will be a major benefit in this drive.
"The format and affordability of this test could allow for greater decentralization and reach of cervical cancer screening in resource-limited settings, a critical step in pursuit of global cervical cancer elimination," Kundrod et al. conclude in the study.
In the meantime, you can check out these tips for what to do if you have HPV.