Self sampling cervical screening test might be one step closer

Yesterday, new research was announced at the NCRI conference about self-testing for HPV, which could revolutionise our cervical screening programme. Our Communications Officer, Lydia Brain, discusses the research.

99% of cervical cancers are caused by human papillomavirus (HPV), and with effective vaccination and screening programmes for the high risk HPV strains, it is thought that cervical cancer is almost wholly preventable. Adeola Olaitan, Consultant Gynaecological Oncologist from UCHL, says: “Cervical screening saves lives because it can detect and where appropriate, treat women with abnormal cells on the cervix which if undetected and untreated, puts the woman at risk of cervical cancer. Despite the success of the screening program, three women a day still die of cervical cancer in the UK and in the developing world, cervical cancer remains one of the most common causes of cancer deaths.”

Numbers of women going for their cervical screening test is at a 21 year low, the ‘Jade Goody’ effect is wearing off and for a whole host of reasons women aren’t attending their cervical screening test.

There are a number of reasons, either logistical, physical or psychological, that may be affecting individual women and preventing them going for their screening. Logistical and practical barriers, such as getting time off work for an appointment, transport issues, finding care for children and dependant family members as well as added barriers for women with limited mobility and the availability of hoists at surgeries for wheelchair dependant women.

Not only are there some physical barriers which might prevent a woman attending their screening, there are many reasons which may make a screening test psychologically difficult. The current test requires a trained doctor or nurse to examine the woman, insert a speculum and use a brush to sweep some cervical cells to go for testing. For women who have been affected by FGM, sexual abuse and for trans men this can be an invasive and traumatic process. The nurse or doctor doing the test can help by providing extra emotional support, and make practical changes such as extra time in the appointment and a smaller speculum, but for some the current screening test is just too much. There are also a range of a gynaecological conditions which may make screening more uncomfortable and harder to carry out such as vaginismus, lichen schlerosus or vaginal atrophy, again for these women there are things that can be adjusted and done to help make the process easier, but for many these adjustments are not yet enough.

There isn’t one fix all solution to make screening easy and accessible to everyone that is eligible, but for many an at home self-testing method would be a good step in the right direction to allow them to participate in the screening programme, Prof Emma Crosbie, University of Manchester, says, “Barriers to cervical screening include embarrassment, inconvenience and fear of speculum examination, all of which can be overcome by self-sampling. Vaginal self-sampling is equally effective at high risk HPV detection as routine cervical screening and some countries have already introduced this as an option for those who have not attended their routine screening appointments”.

Yesterday afternoon, Dr Nedjai from Queen Mary University in London presented their results of a self-testing urine and vaginal swab at the NCRI Cancer Conference in Glasgow, and it seems we might be getting closer to a self-testing method being available. The study is the largest to test for the S5 methylation classifier (a chemical change to one of the four DNA base that make up the human genetic code.

The test looks at the methylation of four HPV (human papillomavirus) types most strongly associated with cancer and a human gene to calculate a risk score. 620 women who had abnormal cells on their cervical screening test or who were found to have a high risk HPV were asked to take the self-sampling vaginal swab and do a urine sample.

The S5 self-test correctly identified high-risk pre-cancerous cells in 96% of the women compared with 73% with an HPV-16 or 18 test.

Dr Olaitan welcomes every strategy to improve uptake of cervical screening and to make the test more acceptable to women, but “While self-sampling by urine or vaginal swabs shows promise, it is not yet as good as screening done by health care practitioners. I have no doubt that this and other research programs will work to increase the performance of self-sampling tests and in due course make cervical screening acceptable and accessible to all women”.

Prof Crosbie can see one disadvantage to the self-test, “The main disadvantage to self-sampling has been the requirement to attend for routine screening if the self-sample tests high risk HPV positive. This is necessary to find those women in whom HPV has had a deleterious effect on the cervical cells, so that those at high risk of cervical pre-cancer can be referred to colposcopy for biopsy and possible treatment, whilst avoiding referral and over-treatment in those who may have a transient HPV infection that will clear spontaneously.”

So it seems we are getting closer to women being able to self-test, which may make being screened an easier and more comfortable experience for women, that will hopefully dramatically increase uptake. Some more work needs to be done to make sure this test is just as effective and women at a higher risk don’t drop off from getting the next stage of testing and treatment they need. Moving towards self-sampling can hopefully save women from the trauma of cervical cancer and treatment and this can only be a good thing.