Cervical cancer is the second most common cancer in women, with an estimated 530 000 new cases every year worldwide. Every year, more than 270 000 women die from cervical cancer; more than 85% of these deaths are in low- and middle-income countries.1
Ulf Gyllensten is a Professor in Medical Molecular Genetics at the University of Uppsala, Sweden. Ulf was kind enough to participate in an interview about his work in cervical cancer screening and his thoughts and hopes for the future. Ulf received his PhD in Genetics in 1984. From here he has held various positions in research universities around the world. Ulf has been a consultant for the likes of Perkin-Elmer AB and Roche Molecular Systems.
HPV testing can be used to screen for cervical cancer. Could you explain what it is and how much of a need/opportunity there is to perform the HPV test? How does it compare to the Smear test in terms of reliability and accuracy?
The HPV test is emerging as the primary test for cervical cancer. Cervical cancer, which is the second most common cancer in women, is caused by a chronic HPV infection. Until now the cancer has been identified using the PAP smear test. However, this test is subjective and it does not directly detect HPV infection, but the signs of an infection in terms of cell changes. There is now a general recognition that replacing the PAP smear with the HPV test will enable a more efficient screening and detection of women at risk. Treatment of early stages of cervical cancer is quite mild, and the prognosis is very good, so early detection is key to a successful screening program.
For those that are not familiar with your work could you give us an overview of the study you are currently running on self- collection HPV tests effectiveness for cervical cancer? What do you hope to discover that could be applied to current cervical screening initiatives?
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. This results 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 to have to attend a midwife’s reception for screening. The results of self-collection for HPV testing have also been as good as when the sample is taken by a trained professional. Thus, we are comfortable that the results are representative and that we are not missing any infection by self-collection.2
What do you think the benefits are in introducing self-collection HPV tests to individuals living in developing countries? How do you think the developing countries themselves will benefit from the introduction of this test?
Self-collection is suitable both in countries with an organized screening program, such as Sweden, and in countries that are about to start a program in cervical cancer prevention. The matrix we are using (FTA card) provides a solid support that stabilizes the DNA, even under very demanding temperature and humidity conditions. This means that sampling kits can be transported, distributed and samples send back to the lab, all at room temperature. The HPV test can be performed in a central health care facility, providing a high quality diagnostic typing. This is a more efficient screening system that using PAP-smear typing, since this requires access to a number of qualified cytotechnicians. Also, PAP smear is inferior as a test for cervical cancer, as discussed before. In summary, combining self-collection with a sensitive HPV test performed at a health care center, represents a very economical way of cervical cancer screening.
How can you see this approach impacting on health in developing countries where this method could prove especially useful? What do you think the impact could be on future cervical screening in these countries and worldwide?
Cervical cancer is actually increasing in many developing countries, in particular as secondary malignancies following HPV infection, and there is a strong need to introduce both HPV testing and vaccination against HPV in young girls. In many developing countries screening programs are completely lacking, and self-collection offers a convenient way to introduce HPV testing without the need to develop cytology based screening. The self-collection format also relieves the primary health care centers, and midwifes, of sample collection duties. In the future we foresee a system where these kits can be distributed via mail, or in developing countries distributed by local health care personnel, and the results transferred either via phone or SMS, resulting in a very economical screening program. Self-collection can also be potentially used for screening for other STDs. We have recently shown that samples can be used to screen also for bacterial and other viral pathogens, in addition to HPV.3
2 – Gustavsson et al. J Clin Virol. 2011 Aug;51(4):255-8. doi: 10.1016/j.jcv.2011.05.006
3 – Ameur et al. Comprehensive profiling of the vaginal microbiome in HIV positive women using massive parallel semiconductor sequencing. Sci Rep. 2014 Mar 18;4:4398. doi: 10.1038/srep04398