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Self-Collection Could Be the Key to Beating Cervical Cancer

HPV, or human papillomavirus, is very common. Almost everyone gets it, but 90% of infections clear up on their own within a couple of years. Of the hundred-or-so types of HPV, 12-15 have been linked to cervical cancer, two of which, HPV16 and HPV18, cause approximately 70% of all cervical cancer. Thanks to HPV vaccines, cervical cancer may be the most preventable cancer.

Micrograph of cervical squamous carcinoma tumor nests. This is a section of tissue from the cervix showing small tumors (light pink, above center) beginning to form. Magnification: x100

Micrograph of cervical squamous carcinoma tumor nests. This is a section of tissue from the cervix showing small tumors (light pink, above center) beginning to form. Magnification: x100

However, cervical cancer is the third most common cancer in women worldwide, and the third greatest cancer killer of women. Every year, there are an estimated 530, 000 new cases and more than 270, 000 deaths from the disease. More than 85% of those women who die of cervical cancer live in low- and middle-income countries.1

There is a clear imbalance that needs redressing, that has several deep-rooted causes.

The Pulse interviewed Dr Philip Castle, the Executive Director of Global Cancer Initiative, and the Executive Director of the Global Coalition against Cervical Cancer, also known as GC3. Dr Castle is keen to see leaders in healthcare technology partner to make cervical cancer screening more accessible to lower-income countries. He says that, while the developed world has seen huge successes in the fight against cervical cancer, resource-limited countries are lagging behind at a terrible cost.

“The prevention of cervical cancer up until now has been quite limited to the high resource settings, and of course those have been spectacular successes,” he said. “But they have not translated to global cervical cancer prevention.”

Typically, cervical cancer screening is carried out using the Papanicolaou test, Pap test for short. It involves a trained healthcare professional using a swab to scrape the lining of the cervix, obtaining a sample of cervical tissue then analyzing the sample in a specialized laboratory. “On the one hand, [the Pap test] has been incredibly successful,” said Dr Castle. “But only in a relatively small number of countries: those with a lot of resources.”

Despite its success, the Pap test has its faults. Unfortunately those faults impinge on its use in under-resourced parts of the world. “There’s a lot of cost in setting up the lab and doing it right,” adds Dr Castle. “It’s a subjective test, it’s hard to maintain. You have to invest in quality control to maintain performance and have feedback… there’s a variety of steps.”

What’s more, some cultures ostracize women who go for screening. Many still believe that HPV and cervical cancer are indicators of promiscuity or infidelity, whereas in actual fact, almost everyone comes into contact with HPV at some point in their lifetime.

But while cervical cancer screening is done by Pap test, testing for HPV itself requires much less in the way of invasiveness and clinical expertise. Testing for the types of HPV known to cause cervical cancer can give peace of mind to millions of women without the social and physical stress of going for a Pap test. There is now an easier way of collecting samples for HPV testing. So easy, in fact, that women can collect their own samples themselves, whenever and wherever is most convenient to them, before taking them to be tested in a lab.

“These [are] what I would call third generation tests, and they don’t require much technical skill to run them,” said Dr Castle.

One method of self-collection involves the use of a cervical brush and a chemically treated sample collection card made from a paper-like material. The chemicals present within the collection card stabilize the DNA from the HPV sample at room temperature, allowing the sample to be easily transported and preserving the DNA for later analysis in a lab. The convenience of this method could allow screening programs to reach wider and more remote populations. The effects of this are thought to be profound.

Ulf Gyllensten, Professor in Medical Molecular Genetics at the University of Uppsala, Sweden, is amongst the researchers currently trialing this method is.  Speaking to GE in early 2015 he said, “We have been pioneering the use of different kits for self-collection of cervical (and vaginal) fluid for HPV testing since 2010. The reason is that we believe that self-collection will enable women to take the sample when and where they find suitable, resulting in a higher attendance rate and population coverage of the screening.”

“The results have been very promising in that most women see this as an opportunity not having to attend a midwife’s reception for screening,” he added. “The results from self-collection for HPV testing have also been as good as when the sample is taken by a trained professional.”

 

References

1 – Human papillomavirus (HPV) and cervical cancer, WHO fact sheet (September 2013). [Online.] http://www.who.int/mediacentre/factsheets/fs380/en/

More Information

http://newsroom.gehealthcare.com/qa-ulf-gyllensten-self-collection-hpv-tests-future-cervical-cancer-screening/

http://www.uu.se/en

www.gelifesciences.com/dxcomponents