Cervical cancer and cervical smears

Jade Goody's much-publicised battle with cervical cancer helped to raise awareness of the disease. Make sure you know how to protect yourself.

Cervical cancer is the third most common women's cancer in the UK after breast and ovarian cancer. Of the 3.4 million women aged 25-64 years who take part in the national cervical screening program, around 6 per cent (just over 200,000) have an abnormal smear and 129,000 women are referred for colposcopy.

But although just over 2,700 women are diagnosed with invasive cervical cancer each year, many have not had regular smear tests. The earlier cervical cancer is diagnosed, the better the chance for a cure.

Most women who die from cervical cancer have never had a smear test at all. The smear is a routine test for detecting early changes in the cells of the cervix. Sometimes abnormal cells are spotted when the smear test is studied under a microscope.

These abnormal cells are not cancerous but if left untreated they can sometimes go on to develop into cancer of the cervix.

What is cervical cancer?

Cervical cancer is a disease in which cancer cells are found in the tissues of the cervix, which is the opening of the uterus. Experts do not know exactly what causes cervical cancer, but studies show that, in most cases, the human papillomavirus (HPV), is a primary cause.

The normal cervix is a healthy pink colour and is covered with scale-like cells called squamous cells. The cervical canal is lined with another kind of cell called columnar cells. These cells are more easily inflamed than the squamous cells.

But the area where the two cells meet - called the transformation zone (T-zone) - is the most likely area for abnormal cells to develop. The T-zone is more exposed on the cervix of young women (teens and twenties), making them more susceptible to cervical infections.

Although the cause of cervical cancer is not yet fully understood there are a number of factors which are linked to a greater risk: Age. Most cases of cervical cancer occur in women over the age of 35 although it may be increasing in frequency among women aged 20 to 35. Older women can be at risk because they may mistakenly believe that, after menopause, regular smear tests are not necessary. Sexual history. Having sex at an early age, multiple sexual partners or a history of unprotected sex or sexually transmitted disease are linked to a higher risk. Smoking cigarettes. This is possibly due to an effect upon the immune system. Low immunity, because of certain illnesses (including HIV), organ transplants, or medications that suppress the immune system. The greatest risk factor for cervical cancer is not having regular smear tests.

Cervical cancer and human papilloma virus (HPV)

The link between cervical cancer and sexual activity led to the discovery that that the human papilloma virus (HPV), which is transmitted sexually, is to blame in most cases. There are over 90 different strains of HPV. Some strains (mainly types 6 & 11) are associated with genital warts, but high-risk strains (especially types 16 and 18) can cause the cellular changes that can lead to cervical cancer.

HPV is passed on by skin-to-skin contact in the genital area, which means that full sexual intercourse is not always necessary and - although condoms reduce the risk of exposure by around 70 per cent - they do not offer full protection. Having HPV does not mean that a woman has been promiscuous or careless.

Only one sexual experience is needed to catch HPV, and it is so widespread that some experts believe it is almost inevitable that sexually active women will acquire it at some point in their lives, most often in adolescence or early adulthood when they become sexually active. However, many women with a healthy immune system clear the virus.

If it is not cleared, it is usually many years before abnormal cells develop in the cervix and having regular cervical smears will detect these changes and allow treatment before cervical cancer develops.

So, while almost all women who develop cervical cancer have HPV, not all women with the virus will develop cervical cancer.

In the very early stages of pre-cancer of the cervix there are usually no symptoms, which is why it is so important to have regular cervical smears.

Symptoms are more likely to appear when the abnormal cells in the cervix have progressed to cancer. The most usual symptom is abnormal vaginal bleeding, which may occur between periods, during or after sex, or at any time after the menopause.

Other symptoms may include a vaginal discharge or painful sexual intercourse.

If you have any of these symptoms see your doctor, but remember that they may be due to other conditions which are less serious than cervical cancer.

Screening for cervical cancer is performed by offering women regular cervical smear tests. The test is offered to all women in the UK, from the ages of 25 to 64, every three years up until the age of 50, then every 5 years.

Women over the age of 65 who have had three consecutive negative smears are no longer recalled as their risk is very low. Despite the cervical smear test's record as a safe and highly accurate screening tool for cervical cancer and precancerous abnormalities of the cervix, many women sadly still do not have regular smear tests.

You should be notified automatically by your doctor or health authority for a test (which may be carried out by the practice nurse), but if this does not happen don't hesitate to make an appointment yourself. The best time to attend for a cervical smear is two weeks after your period.

A cervical smear test is a simple procedure. The test may be uncomfortable but should not be painful. You can ask for it to be performed by a female doctor or a nurse.

A speculum (the standard device used to examine the cervix) is placed in your vagina and cells are skimmed from the surface of the cervix around the T-zone with a special brush. The head of the brush is then broken off into a small glass vial containing preservative fluid and sent to the laboratory for preparation and analysis.

This procedure, called liquid based cytology, is more accurate than the older test in which cells are collected with a wooden spatula and smeared immediately onto a microscope slide.

Each smear contains roughly 50,000 to 300,000 cells. Occasionally the sample of cells is inadequate and a repeat smear is needed. Though not infallible, when properly performed according to established guidelines the cervical smear test detects the vast majority of cervical cancers, usually in the early stages when likelihood of a cure is the greatest.

Research continues for ways to improve the accuracy of the cervical smear test, including using new computer programs, but it is too soon to say whether these will be helpful.

Tests are also being devised to detect the presence of HPV which may help in the diagnosis of early cervical cancer.

If you do not hear from the doctor you should call to check the result of your smear test; the receptionist should be able to tell you how long it will take to come back.

You will be called by your doctor in one of the following situations:

A repeat smear test is advised - because the original test had an inadequate number of cells on it, or there was an infection in the cervix at the time of the smear. A 'borderline' result is reported. The laboratory has found some abnormal cells, but not enough to cause great concern, although a repeat test in 6 months will be advised. Abnormal cells ('cervical dysplasia') have been found and you need further investigation.

Cervical dysplasia means that some degree of transformation in a cell or cells in the epithelium (the tissue that covers the cervix) has occurred. Other procedures are necessary to confirm smear test abnormalities and all abnormal smear tests should have some form of follow-up.

This may include a 'watch and wait' approach with re-testing in several months or, depending on the degree of abnormality, a colposcopy (examination of the vagina and cervix using a colposcope, a modified microscope that views the cervix under magnification) and/or biopsy (a procedure that removes a small sample of tissue from one or more areas of the cervix for examination by a pathologist). Remember, an abnormal cervical smear test result does not mean you have cervical cancer.