https://publichealthmatters.blog.gov.uk/2017/01/25/why-a-change-to-cervical-screening-will-offer-more-accuracy/

Why a change to cervical screening will offer more accuracy

The cervical screening programme in England prevents an estimated 4,500 deaths from cervical cancer every year and a change in the testing process is set to further increase accuracy – and reduce anxiety – for women in the near future.

The cervical screening programme in England prevents an estimated 4,500 deaths from cervical cancer every year,  and a change in the testing process is set to further increase accuracy – and reduce anxiety – for women in the near future.

Nearly all of cervical cancer is caused by a virus called Human Papilloma Virus (HPV). This is a very common virus, and most people who get HPV will clear it by their immune system without requiring any treatment, but in a small number of people the virus persists and can cause abnormal cells that can lead to the development of cervical cancer. There is now a way of testing screening samples directly for types of HPV that can cause these abnormalities.

Currently, cervical screening samples are examined under a microscope to look for abnormal cells that could go on to develop into cancer. This is known as cytology.

If the cytology shows slightly abnormal cells (low grade dyskaryosis) then a second test is done to see if there are high risk strains of HPV present in the cells. If HPV is present and the cytology showed slightly abnormal cells then women are referred for a colposcopy. For results that show very abnormal results (high grade dyskaryosis) then the woman is referred straight away to colposcopy without the HPV test.

As 99.7% of cervical cancers are due to persistent HPV infection, finding out whether HPV is present is a better guide for future tests and treatment.

What is changing?

Following a successful pilot programme and a recommendation by the UK National Screening Committee, a new testing process will be rolled out across England over the next few years to test screening samples for HPV first, rather than after, cytology.

This will ensure that the cause of cervical cancer can be spotted and treated earlier, meaning women can be monitored more closely and any developing abnormal cells found sooner. If no HPV is present, it also minimises over-treatment.

The new test will therefore be more accurate, more personal and should help to reduce anxiety among women.

What is staying the same?

Women aged 25 to 49 will still be invited for cervical screening every three years and women aged 50 to 64 continue to be invited every five years.

The evidence demonstrates that cervical screening in women under 25 would do more harm than good, as cervical cancer is extremely rare in women under 25, despite cervical abnormalities being relatively common. A recent study found that for every 100,000 women invited for screening from the age of 20, the overall number of cervical cancers would not be reduced but an additional 8,000 women would undergo further investigation and an extra 3,000 women would receive treatment for cervical abnormalities.

Being referred for unnecessary medical treatment and further investigations has little or no clinical benefit but is likely to cause a considerable amount of anxiety for the women involved. Repeated treatments for cervical cell abnormalities are not without risk and can increase the risk of premature births if a woman goes on to become pregnant.

Women who have symptoms such as abnormal vaginal bleeding require investigation and should be follow the appropriate pathway.

Improving future outcomes

HPV is a very common sexually transmitted infection, which is why adolescent girls are offered a vaccine that immunises them against the majority of the high risk strains of HPV that are associated with cervical cancer.

Since the introduction of the HPV vaccination programme for teenage girls in 2008, we have seen evidence of a reduction in the number severe cell abnormalities in screened women aged 20 to 24, and when the first cohort of women vaccinated at school enter the cervical screening programme at age 25 in 2020, we expect to see evidence of further impact of the HPV vaccination.

The HPV vaccine will reduce the already low rates of cervical cancer in young women and mean they will be protected for many years. At some point in the future this may lead to further evaluation and redesign of the national cervical screening programme.

For now, we strongly encourage eligible women to attend their routine cervical screening appointment when invited. PHE is supporting local services to encourage more women to attend screening through clearer information and tailored reminders.

While this is not a test for cancer, the test aims to identify any abnormalities that, if left untreated, could develop into cancer, and remains the best preventative measure that we have.

You can read more about cervical screening on the NHS Choices website.

 

1 comment

  1. Hayley

    I believe the first cohort of women who had HPV vaccination have already entered the programme? Although it started in 2008 with 12/13 year olds, there were also huge catch up cohorts of up to 18 year olds during that year, these girls are now of an age where they are invited for cervical screening (now around 27 years old). The HPV primary screening pilot write up even mentioned that the first cohorts were entering in 2015.

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