A 3d rendered image of HPV cells

Almost all cervical cancers are caused by the human papilloma virus (HPV), depicted above.

This week, Wales announced changes to their cervical screening programme.

The change – which will bring Wales in line with the recommendations of the UK National Screening Committee – advises that all people with a cervix aged between 25 and 64 are invited to cervical screening every 5 years. This is different to what’s been happening, where women aged 25 to 49 have been invited to cervical screening every 3 years and women aged 50 to 64 have been invited every 5 years.

It’s a decision that’s made headlines, with many people worried that the longer interval between screening tests will result in cervical cancers being missed.

But there’s more to this change than meets the eye.

The extension from 3 to 5 years between screening has been recommended because the test used in cervical screening has changed. The new test detects who is at higher risk of developing cervical cancer more accurately than the previous test used in cervical screening. This means that the current intervals between screening tests can be safely extended for people who are not at high risk.

The new and improved programme

To understand why the new cervical screening test is better at spotting women at higher risk of cervical cancer, it’s helpful to know how cervical cancer develops.

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

8 in 10 people will be infected with HPV at some point in their lives, but in most cases the infection will be cleared on its own and they will never know they had it.

However, sometimes these infections aren’t cleared. This is when damage to DNA can happen, which causes changes to the cells in our body. 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.

Graphic explaining how HPV causes cancer.

Copy this link to share our graphic. Credit: Cancer Research UK

The previous cervical screening test aimed to detect unusual changes in the cervix.

The new test involves the same procedure of taking a sample from the cervix but tests for HPV first – known as ‘HPV primary testing’. As having HPV infection comes before abnormal cells developing, HPV primary testing detects women at risk of developing cervical cancer at an earlier point.

Why the switch to 5-year intervals?

Screening every 5 years with HPV testing offers at least as good protection as the old test being offered every 3 years. Cervical cancer usually takes many years to develop and if someone tests negative for HPV, then their risk of developing cervical cancer in the next 5 years is very small.

What about the rest of the UK?

The UK National Screening Committee has recommended that all UK nations implement the new cervical screening test and intervals. Scotland and Wales are the first to implement the new intervals, with England to follow suit. Northern Ireland has not moved to HPV primary testing, but we hope this change will be implemented soon.

If a person’s sample tests negative for HPV, they will be invited back for routine cervical screening in 5 years . This is because their risk of developing cervical cancer is very low.

But if their result indicates the presence of HPV, they will be invited back for screening sooner or referred for other tests depending on whether there are also signs of abnormal cells in the cervical sample.

So, the new test allows women to be invited back for screening based on their risk of developing cervical cancer, rather than just their age.

It’s important to remember that no cancer screening test is 100% accurate and a negative result doesn’t guarantee a clean bill of health. If you spot any changes that aren’t normal for you, speak to your doctor. Cancer screening is for healthy people who do not have any symptoms, so if you notice anything that doesn’t feel right between screens, then don’t wait for your next appointment, speak to your doctor straight away.

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