Page last updated at 03:12 GMT, Thursday, 15 May 2008 04:12 UK

Hope over smear test alternative

Cervical smear showing HPV infection
All women aged 25 to 65 are offered smear tests in the UK

A test for the common sex infection human papillomavirus (HPV) may be better at screening for cervical cancer than smear tests, a study suggests.

London's Hammersmith Hospital found testing for HPV was so sensitive it only needed to be done every six years - compared to three years for smears.

The study of 3,000 women also showed that HPV testing was more accurate, the International Journal of Cancer said.

But experts warned more research was needed before changes to screening.

There are many different types of HPV strains and between them they are responsible for almost all cases of cervical cancer.

I think the evidence is almost there to start using HPV testing instead of smears
Professor Jack Cuzick, lead researcher

UK health chiefs have responded by agreeing to the roll-out of an HPV vaccination programme for schoolgirls from this autumn.

But for a number of years researchers have been looking at whether an HPV test could replace smear testing, which is carried out in women aged 25 to 65.

Previous studies have also found it is a more effective test, although some believe it should be used in combination with smear testing rather than as a replacement.

Smear tests look for abnormal cells, whereas the HPV test looks for signs that the cancer-causing virus is present. However, the presence of either does not mean cancer is present or set to develop.

Smear testing can also miss cancer and therefore screening is not a perfect system - although more cervical cancers are thought to develop from people failing to have smear tests than getting false results.

Risk

In the latest study, researchers carried out both HPV tests and smear tests on women aged 35 and over attending cervical cancer screening at 40 GP surgeries.

Results showed that the risk of developing cervical abnormalities at one, five and nine years after a normal smear test was 0.33%, 0.83% and 2.2%.

For a negative HPV test, it was 0.19%, 0.42% and 1.88%.

The research also showed that the while the protection offered by a smear tests wanes after three years, HPV testing, which is carried out in the same way, lasted for six years.

Lead researcher Professor Jack Cuzick said: "I think the evidence is almost there to start using HPV testing instead of smears for women, using smear testing when HPV is found."

But the study admitted more research was needed, particularly on the effectiveness for younger women and the cost effectiveness.

In previous research HPV tests have been found not to be as predictive of cervical cancer in younger women, mainly because they are more likely to be experiencing new infections, many of which are cleared.

In contrast, the test is more likely to detect persistant infection in older women, who are less likely to be exposed to new infections.




SEE ALSO
Smear 'best cancer test'
03 Apr 03 |  Health
New smear test delayed
27 Mar 02 |  Health
Thumbs up for extra cancer test
08 May 02 |  Health

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