What is a Pap smear?
A Pap test (or Pap smear) is a quick and simple test that checks for changes in the cells of your cervix. Dr Iris Wang will use a speculum to be able to see your cervix, and take a sample of cells from its surface. This might be uncomfortable, but it should not hurt. The cells are put on a glass slide, which is then sent to a laboratory for analysis. The results are usually available within a week.
If left undetected, changes in your cervical cells can lead to cervical cancer. If detected early, however, abnormal cells can be monitored and treated to prevent cancer.
Cervical cancer used to be very common in relatively young women. Since the introduction of regular Pap tests, it is now almost non-existent. Unfortunately, 80% of women who do develop cervical cancer have not had regular Pap tests.
If you are aged between 18 and 70 and have ever been sexually active, you should have a Pap smear once every two years, even if you have had the cervical cancer vaccine. This includes lesbians, women in long-term relationships, and women who are no longer sexually active.
What can a Pap smear detect?
The Pap smear is a simple and very effective cancer prevention screening test. A Pap smear can detect changes to the cells of your cervix that may lead to cervical cancer – a disease where normal cervical cells change and multiply to form a growth or tumour.
The Pap smear is unusual compared to other screening tests because it detects changes before they become cancerous. There are very effective treatment options available. Cells that may have become cancerous in five years’ time are effectively removed.
Common queries about Pap smears
An abnormal Pap smear does not necessarily mean that you have signs of cervical cancer. Sometimes, a Pap test is abnormal because you have a minor vaginal infection. There are also three levels of cell changes in the non-cancer range before progression into cervical cancer, classified at CIN I, CIN II and CIN III. The goal of Pap tests is to detect changes in these stages, before they become cancerous. For cancer to develop, surface cells will have cancerous changes, as well as signs of ‘invasion’ outside the cells.
The accuracy rate of Pap smears is about 95%. If cell changes are detected, you will undergo an additional test called colposcopy, which improves the accuracy and identifies the level of your diagnosis – be it CIN I, II or III.
If you are found to have cell changes that may lead to cancer, your treatment will depend on the level of changes. CIN I changes have a 50% chance of reverting back to normal, whereas CIN II and III changes are more likely to progress to cancer. This progression, if it occurs at all, is likely to happen over a period of years. Treatment for women with CIN II or III involves removing the small affected area of the cervix in a simple day surgery procedure. There is no proven medical treatment in the form of tablets or topical creams.
Abnormal cervical cell changes are usually thought to result from past human papillomavirus (HPV) infections. There are different types of HPV infections and only some of these cause cervical cell changes.
HPV, like other viral infections such as those associated with colds and flu, is usually cleared by the person’s own immune system. Unlike colds and flu, HPV usually has no symptoms. But certain types of ‘high risk’ HPV infections can incorporate the viral DNA into cervical cell DNA structures. With time, this can create more and more abnormal changes, and finally develop into cancer.
It is believed that HPV is usually sexually transmitted. Unlike other sexually transmitted infections (STIs) such as chlamydia and gonorrhoea, HPV does not cause tubal obstructions or infertility. As the cell changes can take some time to develop, doctors cannot say when the infection happened or which partner was the culprit.