Family doctor

What is it?

The Thin Prep cervical smear test is a new development in pap smear testing, using new liquid based technology.

Cervical smears are designed to identify pre-cancerous abnormalities to ensure appropriate treatment is given as soon as possible. However, there has been no change to conventional pap smears since 1950, and the old technology has several limitations.

The traditional smear has a high failure rate, and is estimated to be 80 percent accurate. The new Thin Prep test has improved accuracy by about 54 percent.

With traditional smear tests, cells are taken from a the cervix and smeared onto a glass slide for examination. However, there is room for error with this method because the cells can dry or are covered by blood and mucous, obscuring any abnormal cells.

With the Thin Prep test, the cells taken from the cervix are rinsed in a small vial of special solution to preserve the cells. At the laboratory a machine is able to separate the blood and mucus from the cervical cells which are then tested for abnormalities.

Studies in the USA, Australia and Switzerland have shown that the Thin Prep test significantly increases the ability of the doctor and laboratory to identify cervical abnormalities.

One study of 6,747 smears found Thin Prep identified 65 percent more low grade cervical lesions and 36 percent more high grade lesions, compared to the conventional method.

Advantages:

Due to the extra sensitivity of the Thin Prep test there is less likelihood of being recalled for testing.

The Thin Prep improves the chance of disease being detected and early treatment of pre-cancerous changes on the cervix.

The new test reduces the rate of false negative reports when disease is in fact present.

However, it is important to emphasise that no test is available to make cervical smear testing 100 percent accurate. Therefore, it is important for women to have regular smears, usually every three years to ensure any pre-cancerous changes are identified as soon as possible. Women who have already had an abnormal smear may require a cervical smear more often.

Future trends:

The test is currently only approved to test for abnormalities on the cervix such as pre-cancerous changes and the human papilloma wart virus (HPV). However, it is likely modifications of the test will be used to screen for sexually transmitted diseases in future such as chlamydia, gonorrhoea, and HIV.

Computer-aided laboratory testing may also used in future to identify which smears are completely normal and do not need scrutiny by a cytologist.

Getting help

You can request the new Thin Prep test from your regular cervical smear taker (there may be an additional cost).