Cervical cancer diagnosis and screening

Screening for and diagnosing cervical cancer

The cervical smear test enables abnormal cells to be identified and treated become they develop into cervical cancer.

Cells from the surface of the cervix are collected and examined. Any abnormality found on a smear will be evaluated further.

In England, women between the ages of 25 and 49 are invited for a free cervical screening test every three years, those between 50-64 every five years. Women aged 65 and over who have had three consecutive negative results are taken out of the recall system. Women aged 65 and over who have never had a test are entitled to one. In Wales women aged 20-64 are invited for a smear test every three years, in Scotland women aged 20-60 are invited for a smear test every 3 years, and in Northern Ireland women aged 25-49 are invited for a smear test every 3 years and between ages 50-64 every five years.

You may be invited for screening more often depending on the results of earlier tests.

Smear tests are still important even if you've had the HPV vaccine.

If a high-risk type of HPV is found in women with an abnormal smear test, doctors are more inclined to do a colposcopy (magnified examination of the cervix).

If a second smear test is abnormal or the HPV test is positive, your GP or clinic will visually examine your cervix by colposcopy and will take a tissue sample (biopsy) of any apparent abnormality for evaluation.

Colposcopy is a procedure similar to a pelvic examination. It can usually be done in the hospital out-patient department.

• The examination uses a type of microscope called a colposcope to inspect the cervix. The entire area of the cervix is stained with a harmless dye to make abnormal cells easier to see.
• The colposcope magnifies the cervix by eight to 10 times, allowing easier identification of any tissue that appears abnormal and may need biopsy. These abnormalities may be an early step in the series of changes that can gradually lead to cancer.

Precancerous changes

LLETZ, or Large Loop Excision of the Transformation Zone, involves cutting out the area of the cervix where the abnormal cells develop. LLETZ is simple and quick to carry out, and can be done under local anaesthetic.

A cone biopsy is a minor operation that you will have under an anaesthetic. You will usually have an overnight stay in hospital. A small cone-shaped sample of your cervix is removed for examination. The cone includes the whole area of the cervical canal where there might be abnormal cells.

LLETZ and cone biopsy procedures produce tissue samples in which the types of cells and how much they have spread to underlying areas can be more fully determined.

Over the years, different terms have been used to refer to abnormal changes in the cells on the surface of the cervix. These changes are often called dyskaryosis or CIN (cervical intraepithelial neoplasia). "Dysplasia" refers to an area of abnormal tissue; intraepithelial means that the abnormal cells are present only in the surface layer of cells.

Changes in these cells can be divided into three categories.

• Mild dyskaryosis/CIN 1: One third of the thickness of the skin covering the cervix has abnormal cells. These lesions may go away on their own, but over time, they may become more abnormal, so it’s important to have them monitored.
• Moderate dyskaryosis/CIN 2: Two thirds of the thickness of the skin covering the cervix has abnormal cells. Treatment will be needed to remove the abnormal cells.
• Severe dyskaryosis/CIN 3: The full thickness of the skin covering the cervix has abnormal cells. Treatment will be needed to remove the abnormal cells.

Precancerous cells, even high-grade lesions, usually do not become cancerous and invade deeper layers of the cervix for many months, often years.

Ask your doctor if you do not understand the way the result of your cervical smear test is described.