This site is intended for health professionals only

Practice nurse basics - the cervical smear test

Julie Smith
SRN ONC
Specialist Nurse
General Practice Nursing
Chaddlewood Surgery
Devon
E:julielbrsmith@aol.com

Cancer Research UK states that cervical cancer is one of the few cancers that is preventable because precancerous cell changes can be picked up in a screening test.(1) The number of deaths from cervical cancer has been decreasing over the past 20 years, due in part to the introduction of the NHS Cervical Screening Programme in 1987, although screening has been available in the UK since 1967.
However, there are still about 3,000 new cases of cervical cancer diagnosed each year in England and Wales, leading to about 1,200 deaths.
The current test screening programme is based on the "Pap" smear test, named after Dr George Papanicolaou, who discovered that he could detect cervical cancer by studying cells taken from the cervix.

Who should have a smear test and how often?
Women between the ages of 20 and 64 are invited for a smear test every 3-5 years. Just over 8 out of 10 (84%) eligible women have been screened at some time within the last 5 years, and approximately 3-7 out of 10 (~67%) within the last 3 years. About four million women are screened each year in England and Wales.

Where can the test be done?
A woman can have the test at her GP surgery, a family planning clinic, a genitourinary clinic, an antenatal clinic (although this is not normally done as results can be unreliable due to hormone changes), a private health clinic or a voluntary clinic such as a Marie Stopes clinic (see Resources).

Why does the screening interval vary?
The frequency of testing (if previous smears are ­normal) is entirely dependent on the health authority or trust. Some do not think that the cost of performing six extra smears per woman (if the woman is screened every 3 years) is worth spending to reduce the cervical cancer risk by only a few percent.
However, new research from Cancer Research UK shows that women under 50 should probably have a smear every 3 years.(2) The research compared the ­reduction of risk of cervical cancer in women of different ages who had had screens every 3 years with those who had screens every 5 years. The results were most significant for women between the ages of 25 and 49. With 5-yearly screening, the researchers found that an average of 27 cervical cancers developed for every 100 that would have developed if the women were not screened at all. With 3-yearly screening only 16 cancers developed for every 100 that would have if they were not screened. The researchers represented this as 73% protection against cervical cancer with 5-yearly screening, compared with 84% protection with 3-yearly screening, for women aged between 25 and 49.
For women aged 50 or over, there was no difference in the amount of protection given by the different screening regimes. This is probably because abnormal cells seem to develop more slowly in women over 49.

How to perform a Pap smear test
It is important that the woman receives information, both verbally and written, about the reasons for having a smear test, what to expect during the test, and what the results will mean, so that she can make an "informed decision" about the test. Privacy is paramount at all times during the test - the test should take place in a room with a closed door and screened windows, and the client should be provided with a sheet.
The ideal time for a smear test is 2 weeks after the last menstrual cycle has finished. Bleeding can obscure the cells, so this timing will avoid unnecessary repeats.
The following describes the correct procedure for performing a Pap smear test:

  1. Label the slide on the ground-glass side using a pencil (name of client and their date of birth).
  2. Once the woman is comfortable the speculum is gently inserted into the cervical canal. The surface of the ­ectocervix may then be swiped gently to remove any mucus or debris.
  3. The "tongue" of the spatula is introduced into the cervical canal. The "shoulder" is positioned in the 3 o'clock position on the ectocervix at the ­beginning of the procedure.
  4. With gentle pressure the spatula is rotated in a clockwise direction. If the cervical canal is wide the spatula is allowed to wander according to the contour of the cervix during rotation. If after ­rotation through 360o without bleeding it is felt that ­sampling is inadequate, the procedure may be repeated. If bleeding does occur, it can mask the cells that need to be examined, so the client will need to be asked to return for another test.
  5. Once you are happy that the cells have been properly ­collected, the spatula and speculum are gently removed.
  6. The cells on the spatula are always spread on the slide along its long axis, parallel to its edge. If the distribution of the cellular material is uneven, the same spatula may be used for respreading.
  7. The slide is immediately fixed (either by spraying with or dipping into a fixing solution).
  8. Once the slide has been fixed, it should be placed in its carrier and sent to the relevant laboratory.
  9. The spatula is discarded - they may be burnt as they leave no residue.

Liquid-based cytology
Liquid-based cytology (LBC) is a relatively new way of preserving the cells taken in a smear test. The procedure for LBC is similar to that for Pap testing, until the fixing stage. The nurse collects the cells from the cervix in the same way as before, but using a very small brush instead of a spatula. The head of the brush is then broken off directly into a small pot of liquid (a preservative), which is then sent to the lab to be analysed.
The advantage of LBC is that by omitting the fixing stage you reduce the chance of sampling errors. Also, as there is no slide involved, there is less chance of any slide problems, such as poor transfer of the cellular material onto the glass slide. LBC is more reliable at preserving the cervical cells, and so the results are more likely to be correct. Presently, about 1 in 12 Pap smears have to be redone because the originals were not carried out ­properly, and this of course can cause much anxiety and lead to extra cost. With LBC, far fewer smears need to be repeated.
NICE (the National Institute for Clinical Excellence) was asked to look at the use of LBC for cervical screening(3) and has provided guidance to the NHS. The system is being piloted in England but could take up to
5 years to become standard throughout the UK, because of the necessary training of personnel.

Results
The samples are interpreted at a hospital laboratory and returned, usually to the local health authority. The results are usually available within 2-4 weeks. Some health authorities send a letter regardless of the results, while others will send a letter only if a repeat smear is required. It is extremely important that the client understands the setup in her area. The nurse should inform the client how long she can expect to wait for results and should also discuss what the results mean:

  • Normal (85%)- no abnormal cells detected. Routine follow-up in 3-5 years, depending on local policy.
  • Inadequate (currently 10%, should be 7-9%) - impossible to make a cytological assessment
  • (usually due to a test error). Test needs to be repeated within following 2 months.
  • Borderline (4-5% ) - abnormal cell change, but not conclusive of cervical intraepithelial neoplasia (CIN). Test needs to be repeated in 6 months.
  • CIN present (mild 2-3%; moderate/severe: 1.2-1.5%) - increasing levels of cell change (dyskaryosis). Refer client for colposcopy.

Key messages for the client
It is important that women are made aware of the ­following:

  • Cervical screening does not diagnose cancer - but it is thought to prevent 3,900 deaths annually.
  • Its purpose is to recognise abnormal cells that may be precancerous, or even cancerous.
  • Women should always report any abnormal ­bleeding to their doctor.

References

  1. Available from URL: http://www.cancer.org.uk
  2. Watt G. Cervical screening and ­cytology. In: Section of General Practice and Primary Care, University of Glasgow. Continuing professional development summaries of PGEA ­meetings 1998-99. Discourse between generalists and specialists. Glasgow: Division of Community-Based Sciences, University of Glasgow; 1999.
  3. National Institute of Clinical Excellence. Guidance on the use of liquid-based cytology for cervical ­screening. Technology appraisal 69. London:NICE;2003. Available from URL: http://www.nice.org.uk

Resources
Cancer
Research UK
W:www.cancer.org.uk
National Institute for Clinical Excellence (NICE)
Uses a team of experts who provide guidance to both the NHS and patients on medicines, medical ­equipment and clinical ­procedures. These evaluations are called appraisals. Each appraisal takes about 12 months to complete and involves input from the ­manufacturers of the technology, patient groups and professional organisations.
W:www.nice.org.uk
Addenbrooke's NHS Trust
W:www.addenbrookes.org.uk
University of Glasgow
W:www.gla.ac.uk
BBC News Health pages
W:http://news.bbc.co.uk/1/hi/health/default.stm
Marie Stopes  International
W:www.mariestopes.org.uk