About cervical screening

What is cervical screening?

Cervical screening is not a test for cancer. It is a method of preventing cancer by detecting and treating early abnormalities which, if left untreated, could lead to cancer in a woman's cervix (the neck of the womb). The first stage in cervical screening is taking a sample using liquid based cytology (LBC).

A sample of cells is taken from the cervix for analysis. A doctor or nurse inserts an instrument (a speculum) to open the woman's vagina and uses a small soft brush to sweep around the cervix. Most women consider the procedure to be only mildly uncomfortable.

Early detection and treatment can prevent 75 per cent of cancers developing but like other screening tests, it is not perfect. It may not always detect early cell changes that could lead to cancer.

What is LBC?

Liquid-based cytology (LCB) is the method used to obtain your cervical sample for examination in the laboratory. Your sample is collected using a special brush, which gently removes some cells from the neck of your womb. The head of the brush is then either rinsed in, or broken off into, a vial of preservative liquid.

The vial is sent to a laboratory. Scientists there treat your sample to make it easier to examine, and then put the cells onto a slide. This is viewed under the microscope by a specialist scientist (known as a cytologist), who is trained to identify abnormalities in the cells.

Why use LBC?

The NHS Cervical Screening Programme finished rolling out LBC in 2008. Before then, we used conventional 'Pap' smears. We switched to LBC because it makes it easier for scientists to view your cells. This means you are less likely to need to give a second sample because your first test couldn't be read (this is known as an 'inadequate sample').

LBC also means that the laboratory can process your sample more quickly, so you get your results sooner.

What does the NHS Cervical Screening Programme do?

The programme aims to reduce the number of women who develop invasive cervical cancer (incidence) and the number of women who die from it (mortality). It does this by regularly screening all women at risk so that conditions which might otherwise develop into invasive cancer can be identified and treated.

Who is eligible for cervical screening?

All women between the ages of 25 and 64 are eligible for a free cervical screening test every three to five years.

In the light of evidence published in 20031 the NHS Cervical Screening Programme offers screening at different intervals depending on age. This means that women are provided with a more targeted and effective screening programme.

The screening intervals are:

Age group (years)  Frequency of screening
25First invitation
25 - 493 yearly
50 - 645 yearly
65+Only screen those who have not been screened since age 50 or have had recent abnormal tests

The NHS call and recall system invites women who are registered with a GP. It also keeps track of any follow-up investigation, and, if all is well, recalls the woman for screening in three or five years time. It is therefore important that all women ensure their GP has their correct name and address details and inform them if these change.

Women who have not had a recent test may be offered one when they attend their GP or family planning clinic on another matter. Women should receive their first invitation for routine screening at 25.

Why are women under 25 and over 65 not invited?

For more information on the reasons for the age ranges for the programme, see our FAQs.

What about women who are not sexually active?

The NHS Cervical Screening Programme invites all women between the ages of 25 and 64 for cervical screening. But if a woman has never been sexually active, then the research evidence shows that her chance of developing cervical cancer is very low indeed. We do not say no risk, only very low risk. In these circumstances, a woman might choose to decline the invitation for cervical screening on this occasion. If a woman is not currently sexually active but has been in the past, then we would recommend that she continues screening.

How many women are screened?

The programme screens over three million women in England each year. Of the women in the target age group most were tested following an invitation and the rest were screened opportunistically at the suggestion of the sample taker or of the woman herself. For clinical reasons some women have more than one test during the course of a year, and 3.7 million samples were examined by pathology laboratories in 2010-2011.

Click here for the latest statistics on the NHS Cervical Screening Programme.

The national office of the NHS Cancer Screening Programmes, based in Sheffield, is responsible for improving the overall performance of the programme. Set up in 1994, its priorities are to:

  • develop systems and guidelines which will assure a high quality of cervical screening throughout the country
  • identify important policy issues and help resolve them, and improve communications within the programme and to women

Every Primary Care Trust (PCT) has a nominated person responsible for its cervical screening programme and implementing the national guidelines.

Regional directors of public health are responsible for the quality assurance network in their region.

How much does the programme cost and how is it funded?

Cervical screening - including the cost of treating cervical abnormalities - has been estimated to cost around £175 million a year in England.

Primary Care Trusts commission cervical screening from the overall allocation they receive from the Department of Health.

Is cervical screening effective?

Whilst cervical screening cannot be 100 per cent effective, cervical screening programmes have been shown to reduce the incidence of cancer in a population of women. For example:

Percentage of Cancer Preventable

(Protection offered by a single negative (normal) cervical screening test)

 20-39 years40-54 years55-69 years
3-yearly screening 41%69%73%
5-yearly screening 30%63%73%
Sasieni, Adams, and Cuzick, BJC 2003

Coverage of the target population

The effectiveness of the programme can also be judged by coverage. This is the percentage of women in the target age group (25 to 64) who have been screened in the last five years. If overall coverage of 80 per cent can be achieved, the evidence suggests that a reduction in death rates of around 95 per cent is possible in the long term. In 2010/11 the coverage of eligible women was 78.6 per cent3

[1] P Sasieni, J Adams and J Cuzick, Benefits of cervical screening at different ages: evidence from the UK audit of screening histories, British Journal of Cancer, July 2003
[2] Perinatal mortality and other severe adverse pregnancy outcomes associated with treatment of cervical intraepithelial neoplasia: meta-analysis. Arbyn M, Kyrgiou M, Simoens C, Raifu AO, Koliopoulos G, Martin-Hirsch P, Prendiville W, Paraskevaidis E. BMJ. 2008 Sep 18;337:a1284. doi: 10.1136/bmj.a1284. Review.
[3] Cervical Screening Programme, England: 2010-2011

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