This week Seattle is proud to host The 29th International Papillomavirus Conference & Clinical Workshop, and will be sharing two blog posts on our cervical cancer work. This post’s author, Dr. José Jerónimo, is PATH’s senior advisor for women’s cancers.
Recently, we’ve seen tremendous progress in the availability of new, potentially game-changing technologies that promise to help us screen more women for cervical cancer, no matter where they live, and to effectively treat those with precancer.
In the past few years several new human papillomavirus (HPV) tests have become available, including the careHPV test developed by QIAGEN, an international medical device manufacturer, with support from PATH. We’ve completed trials of that field-friendly and inexpensive test, and it is now time to scale it up to reach all of the women who need it. We also have learned that teaching women to use careHPV to gather screening samples themselves frees up the time of busy health workers and can dramatically increase the ability of clinics and hospitals to treat more women with precancer, and thereby prevent cervical cancer.
HPV, the virus that causes cervical cancer (it also can cause penile, anal, and throat cancers) infects nearly every sexually active person, but most of us don’t experience advanced disease because our bodies are able to clear the infection. However, in some women the infection persists, and the disease advances over 10–20 years to a precancerous stage (when it is easy to treat), and years later to invasive cervical cancer. About 266,000 women die from cervical cancer every year, with 85 percent of mortality occurring in the developing world.
That is where PATH is focusing its efforts: low-resource settings in Africa, Asia, and my home region of Latin America.
Guatemala, Honduras, and Nicaragua have declared their interest in partnering with PATH in a project to deploy HPV testing, and related treatment options, through their public health systems. This is big! In the first project year, PATH will “seed” each country with 110,000 careHPV tests, and will work with the respective ministries of health to develop systems for effectively using the test in pilot settings. In subsequent years the countries will purchase careHPV themselves and expand availability. Through the course of the project, we estimate that more than half a million women who would not otherwise have been screened will benefit from the service.
Self-sampling—the key to universal screening?
In addition to increased sensitivity compared to the Pap test or visual inspection, a major benefit of careHPV screening is that it gives good results even with vaginal samples women collect themselves. We have found that when women “self-sample,” the test works nearly as well as when doctors or nurses gather cervical mucus samples during a pelvic examination. Pelvic exams are a rate limiter—the exam takes time, limiting the number of women who can be seen by each trained provider.
Self-sampling has the potential to dramatically increase the number of screenings clinics can organize, and allows them to focus pelvic exam resources on treating the women who test positive for HPV. This is what we mean when we talk about game-changers. Mexico and Argentina already are using self-sampling, and the three PATH project countries will do the same.
To make screening more affordable to countries over the long term, we also are working with the Pan American Health Organization (PAHO) and other partners to create a regional procurement system for screening and treatment products. PAHO member countries already save a lot of money by purchasing vaccines together in bulk orders, and we intend to garner similar savings for cervical cancer prevention equipment too.
New treatment devices overcome old obstacles
That said, screening without treatment is pointless, so we’re looking at both sides of the equation. For years PATH has been recommending cryotherapy (freezing) to treat precancerous tissue, but we also are aware of the challenges related to traditional “cryo” equipment—such as the recurring cost of gas. We are working with the Peruvian Cancer Institute and other partners to assess the performance of a new technology, CryoPen, that freezes tissue but without needing to regularly replace the gas. We’re also collaborating with a US manufacturer of an alternate treatment device that uses heat to destroy precancerous tissue (confusingly called “cold coagulation”), and which can treat up to 30 women with power from a single, portable, rechargeable battery. Working on multiple treatment options increases our chances of success and will give countries a choice.
It feels like many different factors are coming together in the fight against cervical cancer, and this is nowhere more evident than in Latin America. PATH is proud to be in that fight.