A cervical screening, also known as the smear test, is used to detect any abnormal cells in a woman’s cervix. Cervical cells change over time, so it is important to regularly undergo screenings in order to monitor changes.
Most women who undergo a cervical screening will return with a normal result. However, around 1 in 20 smear test results will come back as abnormal. This does not mean cancer, but rather that there are changes in the cervical cells which should be investigated
The cervical surface is covered with cells named squamous cells and the endocervix, which is the cervical canal, is lined by glandular or columnar cells, which produce mucus.
The transformation zone is the area in which these different cells meet and the place where abnormal cells can form. These are where the sample of cells will be taken during the cervical screening test.
Abnormal cells found on the surface of a woman’s cervix are referred to as Cervical Intra-epithelial Neoplasia (CIN). CIN is divided into three classifications, used to describe how far these abnormal cells have developed in the surface layer of the cervix. The changes in cells can be graded as CIN 1, CIN 2 or CIN 3. The higher the grade, the greater surface area of the cervix is affected by abnormal cells – below we outline the different CIN grades and what they mean.
The CIN 1 grade is used to describe mild dyskaryosis, which signifies mild changes to the cervical cells. This affects only one-third of the cervical surface area. These changes definitely do not signify cancer and in the majority of cases will not cause cancer in the future. CIN1 usually corresponds to infection with Human Papilloma Virus (HPV) and will often resolve by itself within six months. Usually, no treatment is required for an abnormal smear showing only mild dyskaryosis. However, a repeat smear test after six months is necessary to monitor changes.
A CIN 2 grade refers to two-thirds of the thickness of the surface layer of the cervix showing cell changes. It is used to describe moderate dyskaryosis and again, does not mean cancer. A colposcopy should be carried out when moderate dyskaryosis is detected and following this, treatment may be required to remove the abnormal cells.
CIN 3 refers to severe dyskaryosis and affects the full thickness of the cervix surface. Even with this result, it is unlikely that a woman already has cervical cancer. However, it is important to treat severe dyskaryosis as soon as the changes are detected. Treatment is used to remove the abnormal area so that these cells do not develop into cancer in the future.
High Grade Dyskaryosis
If you have recently undergone a routine cervical screening, then you may have received a letter stating that your smear was abnormal and that high grade dyskaryosis has been detected. High grade smears include moderate and severe pre-cancerous cell changes, which often require treatment.
Though this diagnosis means it is unlikely that you already have cancer, the abnormal smear test result indicates that if these changes were to be left untreated, they could develop into cancer in the future. It is therefore highly important that all women with severe dyskaryosis and most women with moderate dyskaryosis seek treatment.
Not all abnormal cells require immediate treatment. GPs may recommend a surveillance, or “watch and wait” approach for younger women whose abnormal smear has detected moderate dyskaryosis. This is because in these age groups changes may regress back to normal without intervention.
What causes Dyskaryosis?
Dyskaryosis is normally caused by infection with the human papilloma virus (HPV), which is almost always transmitted through sexual activity. Genital HPV is easily passed through skin-on-skin contact as well as genital contact and oral sex. The HPV virus can remain dormant for a very long time and most people show no symptoms, so there is often no way of knowing when or from whom you contracted HPV.
Practicing safe sex by using condoms or other barrier methods can help to reduce the risk of HPV contraction, but since the virus lives on the skin around the entire genital area, it cannot completely remove the risk of transmission.
There are around 100 HPV strains, 20 of which are thought to cause cancer. Some strains are higher risk than others, particularly types 16 and 18 which are most prevalent and are more likely to cause dyskaryosis. These two strains are responsible for approximately 70% of cervical cancers.
Around 80% of the world’s population will contract some type of HPV in their life and most of the time their immune system will naturally work to rid the body of the virus without treatment. However, a small percentage of people will not be able to clear the infection.
A vaccination is now available through the NHS in the UK to protect against these HPV strains. However, if the infection is already present before vaccination and the changes to cells have already taken place, then it will not be effective.
An expert in colposcopy should assess every patient with high grade cervical changes, to establish the true nature of the diagnosis.
A colposcopy is a simple examination used to examine the cervix and the results can determine whether treatment to remove the cells is needed.
The examination usually takes around 10-20 minutes and involves inspecting the vaginal and cervical tissues using a type of microscope which magnifies the cervix surface between 10 and 40 times its size. A small tissue sample may be taken from the cervix for further examination.
In many cases where it is clear that abnormal cells need to be removed, the medical professional who is carrying out the colposcopy will offer same-day treatment to remove the cells, if the procedure is a relatively straightforward one. Where biopsy results are necessary to determine if cells need removal, or where the procedure needed is more extensive, a separate appointment will be offered.
Treatment for High Grade Dyskaryosis
Once a colposcopy has been carried out and abnormal cervical cells are found, your doctor may suggest treatment to remove them. This is particularly recommended when there is a moderate to high chance of these cells developing into cancer if left untreated.
The aim of all treatments is to remove the potentially dangerous cells while minimising any damage to the healthy cervical tissue. While many people will envisage large inner cervical sections being extracted, in actual fact, normally only an area roughly the size of a fingertip will be removed.
There are several different treatment options used to remove abnormal cells. With high-grade dyskaryosis, the most common one is Large Loop Excision of the Transformation Zone (LLETZ) , which involves using a thin electrically-heated wire loop to remove the abnormal cells while awake and under local anaesthetic.