Cervical Cytology

Your doctor or health care provider performs a cervical cytology test to look for cervical cells that are abnormal or even potentially cancerous. The cell suspension is processed in the laboratory and placed on a glass slide, stained with a special dye, and viewed under a microscope by a cytologist or pathologist. Also, the fluid is analysed for evidence of HPV infection, which may be used to decide how often the woman should be screened for an abnormality in the future. Abnormal cells can be present without causing any noticeable symptoms. Some women with abnormal cells require treatment whilst others may need to be monitored with repeat cervical cytology tests over a period of time as often mild changes resolve on their own.

In England a woman registered with a GP receives her first invitation at the age of 25. There are three-yearly examinations between 25 and 49, and five-yearly examinations between 50 and 65.

Currently, a "negative" cervical cytology test means the cells obtained appear normal. In some instances (less than 3 in 100), the sample may be reported as "inadequate" for evaluation. This generally means there are insufficient cells for reliable assessment. Other reported results are:

• Borderline changes: Cells are present that may indicate HPV infection or where it is uncertain what the cells are. Most borderline changes return to normal without treatment.
• Mild dyskaryosis: These low-grade changes are often associated with HPV and return to normal without treatment.
• Moderate dyskaryosis: This finding indicates that abnormal cells present which may need treatment.
• Severe dyskaryosis: This result indicates that abnormal cells are present. This indicates that high grade pre-cancer (CIN) is probably present and which is likely to require treatment.
• Severe dyskaryosis/?Invasive carcinoma: Abnormal cells are present which indicate that high grade pre-cancer (CIN) is probably present and that cancer needs to be excluded.
• ?Glandular neoplasia: This result means that abnormal glandular cells present. These cells may come from the cervix, the lining of the uterus (womb) or rarely from the ovary.

From mid 2019 onwards, a negative test will also indicate that “high risk” HPV infection has not been identified

Cervical cytology is used as a screening test in the well-established national screening programmes. Occasionally, abnormalities may go undetected with a single test. This is why it is important to be screened regularly. The sample represents only some of cells present on the cervix. Even when carried out by a very experienced nurse or doctor, sample collection can occasionally collect too few cells to give a reliable result and a repeat cervical cytology test may be required. This happens in fewer than 3 in 100 tests. Using HPV testing as the first step should decrease the number of inadequate or unreliable results.

Cervical cytology was formerly known as the smear test. When performed routinely every 3-5 years, it is a great help in the detection and treatment of cervical abnormalities known as Cervical Intraepithelial Neoplasia (CIN). Early detection and treatment of CIN can prevent about 75% of cervical cancers developing.

If you have any abnormal bleeding, for example, after sexual intercourse, between periods or after the menopause, it is important that you speak to your general practitioner. Your GP will be able to tell you whether you need to be referred to a gynaecologist for further investigation. Routine cervical cytology is not appropriate in these circumstances.

The most important risk factor for cervical cancer is infection with some strains of the human papilloma virus (HPV, which can sometimes be called wart virus infection). High risk strains of HPV are found in 99% of cervical cancers. HPV is a very common sexually transmitted virus which most people contract shortly after becoming sexually active. In 9 out of 10 women, the virus is cleared naturally by the body’s immune system within a year.

Vaccines are now available to help prevent infection with the most common high risk types of HPV. In the UK, HPV vaccination is offered to girls aged 12-13 years as part of a national vaccination programme. The vaccine is made available through most schools or general practitioners. It is given in three doses over a period of six months and should ideally be given before a girl becomes sexually active. Even if you have been vaccinated, it is important to continue to accept your invitation for routine screening. This is because HPV infection can occasionally occur in women who have been vaccinated.

Some risk factors such as the age at which sexual intercourse begins (the earlier, the higher the risk) and multiple sexual partners, contribute an increased risk of having the virus. Other factors are infrequent cervical screening, a history of abnormal cervical cytology or treatment for cervical abnormalities, using the oral contraceptive pill and cigarette smoking. Women whose immune systems are less active are also at increased risk and women who are HIV positive are recommended to be screened annually.

For most women, regular 3-5 yearly screening is enough to prevent them from developing cervical cancer by allowing abnormalities to be detected and treated early if needed. More frequent screening may be recommended for women who have had previous treatment for high-grade cervical abnormalities,