New insights on self-sampling for cervical cancer screening

Credit: YouScreen/KCL/North Central & North East London cancer Alliance

Cervical screening aims to prevent cervical cancer from developing by spotting cell changes that could become cancer if left untreated, or spot cervical cancer at an early stage so treatment is more likely to be successful.

In the UK, cervical screening is offered to those aged 25 to 64, and combines testing for a virus called human papilloma virus (HPV) with looking at cells for abnormalities

England has one of the highest cervical screening coverage rates in Europe, but coverage has been declining for approximately 20 years. Coverage is the proportion of eligible people who have been screened within 3.5 years (for ages 25-49) or 5.5 years (for ages 50-64).

In the first study of its kind, funded by us and published in the Journal of Medical Screening, results have revealed that 51.4% of women eligible for cervical screening would prefer self-samplingfor cervical screening, when the patient takes their own sample, over being tested by a clinician if they were offered a choice.

“I think this research has come at a good time and can add to the ongoing conversation round self-sampling.”

We spoke to Hannah Drysdale, doctoral researcher and lead author of the paper, about what these results mean for the future of self-sampling.

What causes cervical cancer?

Virtually all cases of cervical cancer are caused by infection from HPV, a common virus that infects the skin and cells lining the inside of the body. There are over 100 different types and around 13 types, considered “high risk”, are linked to cancer.

Around 8 in 10 people will be infected with HPV at some point in their lives, but in the majority of cases, the infection will go away on its own, without the person ever knowing they had it.

Occasionally, these infections aren’t cleared. This is when damage to DNA can happen, which can cause changes to the cells in our body. In some cases, these cell changes can be resolved on their own, but they can also lead to cancer if left untreated over a long period of time.

What does cervical screening involve?

HPV primary testing’, the process in most of the UK, involves a health professional, usually a practice nurse, taking a sample from the cervix which is then sent off to the lab. The laboratory will check for high risk HPV. If high risk HPV is found, the laboratory will test the sample for abnormal cell changes.

Anyone with a cervix between the ages of 25 and 64 is eligible for cervical screening. The screen is routinely carried out by a health professional at your GP, a sexual health clinic or other specialist clinics.

“The key difference is that with clinician sampling, they use a speculum to open up the vagina so that they can view and take samples from the cervix. This can be tested for HPV and checked for abnormal cells if HPV is found” explains Drysdale. “But with HPV vaginal self-sampling, the person who is having the screening takes the sample themselves, at home, using something that looks a bit like a long COVID swab.”

After the sample has been taken, the swab will be sent to the laboratory in the post, and tested for HPV. A letter with the results will be sent back to the person who has taken the sample and to their GP.

“Only about 1 in 6 women who will have used the self-sampling test will have to go to a doctor for screening to test for cell changes.”

The results are in

This is the first study of its kind looking into all eligible women’s anticipated preferences if they were offered a choice at the point of invitation.

The study, carried out by researchers at King’s College London, analysed questionnaire responses from 3672 women eligible for cervical screening in April 2021.

The questionnaire asked participants’ theoretical preference for self-sampling or clinician sampling before and after receiving information on both. Results found that before information exposure, participants were equally likely to select clinician sampling (42.9%) and self-sampling (42.6%).

However, after reading further information, there was a shift towards self-sampling – 51.4% chose self-sampling while 36.5% selected clinician sampling.

The results revealed that more of the women who sometimes delayed or missed a cervical screening appointment, or who had never attended one, chose self-sampling, compared to regular attenders.

Additionally, at the start of the survey, 379 people said that they did not intend to go for cervical screening in the future. However, after they had been presented with further information, 78.9% of these participants said that they would choose self-sampling in the future.

The questionnaire also collected demographic information to study differences in preferences between different population groups and gathered information on the reasons participants gave for preferring self or clinician sampling.

“The main points people selected as reasons for preferring self-sampling including ease, convenience, reduced embarrassment and increased comfort,” says Drysdale. “The participants were also given the option to provide alternative reasons, some of which mentioned reasons such as taking pressure off the NHS.”

Self-sampling was also found to be more popular among older participants. One explanation for this is that older women can find cervical screening more uncomfortable post menopause, and prefer some non-speculum methods.

On the other hand, women who preferred clinician sampling had more confidence in the test being done correctly by a healthcare professional and would be more likely to trust the results.

The potential impact

Importantly, these results suggest that preferences and decisions can change when people are provided with more information on screening and that providing the option for both clinician sampling and self-sampling has the potential to increase overall screening uptake.

There have been some exciting improvements in our ability to prevent cervical cancer and catch it early, such as the switch to HPV primary testing, and the fact that young people are now offered a vaccine against the main types of HPV which cause cervical cancer. Ongoing refinements to the cervical screening programme, including exploring the option of self-sampling, may help us prevent even more cases and save more lives in the future.

Nicola Smith Senior Health Information Manager at Cancer Research UK

HPV testing of self-collected samples also has the potential to overcome several barriers and may help to reduce inequalities in cervical screening uptake in specific groups of individuals.

Individuals from deprived, non-English speaking and ethnic minority groups were under-represented in the study, but there was an indication that people from ethnic minority groups who had never attended cervical screening were less keen on self-sampling than White people. Therefore, further research is required to assess the impact of self-sampling on the performance of the current cervical screening programme and understand any impact of self-sampling on health inequalities.

Other ongoing studies, such as the YouScreen study, has been offering self-sampling to non-attenders within the NHS Cervical Screening Programme in parts of North East London and North Central London, and will help us understand the potential impact of this option.

What’s next?

The results of this study have highlighted that screening preferences can change when women are provided with more information on their choices, spotlighting the importance of clear communication, something that should be considered if the UK national screening committee was to recommend self-sampling.

While this research has provided key data to the growing conversation around self-sampling, it has also raised a number of questions.

For example, the team of researchers recognise there is often a difference between people’s intentions and their actions. “They call it the intention behaviour gap,” explains Drysdale. “This means that while some women may say that they’ll choose self-sampling, in reality, when it comes to it, they may not actually do that.

“But hopefully, we’ll be able to look at the findings from the YouScreen study and see whether the results from there mirror our results.”

However, importantly, this study is only one element of ongoing research into self-sampling that is helping to paint the full picture. What’s more, Drysdale herself is embarking on a second study interviewing women from different socioeconomic groups to get their points of view on self-sampling vs clinician sampling.

“Australia are offering a choice of self-sampling in the summer following the Netherlands, and Denmark are offering self-sampling to non-attenders in their screening programmes,” Drysdale says. “I think these results are quite timely, because self-sampling is gaining traction.”

The mounting evidence being generated will be considered by the UK National Screening Committee, who will then make a recommendation on whether self-sampling should be offered as part of the national cervical screening programme, and who it should be offered to.

This decision is likely to be a little way off, so considering your cervical screening invitation when you receive one and making an appointment at the GP practice, or sexual health clinic where it’s offered, is still the main option. If you were invited for cervical screening during the pandemic and didn’t go but want to go now, make an appointment with your GP practice.

Whilst there are companies which sell HPV self-sampling kits, the results of private tests cannot be acted on by the NHS cervical screening programme.

Importantly, cancer screening is for people who do not have any symptoms. So, if you notice anything that doesn’t feel right then don’t wait for your next screening appointment, speak to your doctor as soon as you can.

Lilly

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