Experts back HPV test for cervical cancer screening

By Craig Kenny

The UK may be poised to switch to HPV testing as the primary screening tool for cervical cancer in women over 35, Pulse has learned.

The chair of the UK's cervical screening advisory group said the move could be ‘very rational' following new evidence of the test's sensitivity published in Lancet Oncology last week.

The Italian study compared HPV testing with cytology in 81,220 women aged 25 to 60. In the second round of testing, nine invasive cancers were found in the cytology group, but none in those tested for HPV.

Combining HPV and cytology testing did not improve sensitivity, suggesting HPV testing alone was responsible for the increased detection of abnormalities.

In the younger age group, HPV testing led to an over-diagnosis of regressive lesions, which, if treated surgically, can cause problems during pregnancy.

Concern about false positives has delayed its use as a primary screening tool, but the recent introduction of HPV vaccination for girls aged 12 to 13 has eased these concerns.

Professor Henry Kitchener, professor of gynaecological oncology at the University of Manchester, told Pulse there was a growing case for its use as a primary test.

Professor Kitchener, who chairs the UK's cervical screening advisory group, said: ‘In an era with a vaccinated cohort of women, there is a higher chance women will test negative for HPV and you can confine cytology to women who are HPV positive.

‘So it could be a very rational thing to do. And for those who test negative you will be able to extend their screening intervals.'

Professor Jack Cuzick, head of Cancer Research UK's Centre for Epidemiology, says using HPV as a primary test could extend the screening recall period from the current three-to-five years up to six years.

He argues that the UK should switch to using HPV as a primary test. ‘We have been slow to respond because there's a belief that cytology works, but this is a better approach. The weight of evidence is now overwhelming. In long term follow-up cancer rates are much lower.'

Both experts agree the chief implication for GPs would be in counselling women who test HPV-positive, as it is a sexually-transmitted virus that can lay dormant for more than six months.

‘GPs will need to be aware of what HPV means, and how to talk about it to the women they screen,' said Professor Cuzick.

‘We would need to be sure there won't be a cohort of worried women,' agreed Professor Kitchener.

HPV testing is currently being piloted as a secondary test, following cytology, in some parts of the UK. ‘The testing we have done doesn't seem to have produced a large number of psychological adverse effects, although we haven't explicitly studied those,' said Prof Kitchener. ‘We are not getting loads of comments from GPs who are getting calls from distressed women.'

The introduction of the HPV vaccine in 2008 should lead to a 63 per cent reduction in the number of women under 30 diagnosed with cervical cancer over the next 15 years, according to a study in the British Journal of Cancer.

The study assumes 80 per cent uptake. Government estimates that 78 per cent of girls aged 12 and 13 have received all three doses of the vaccine, which protects against HPV 16 and HPV 18, the cause of 70 per cent of cervical cancers.