Testing for the human papillomavirus and following it with a smear test could be the most effective approach for cervical screening, according to a new analysis.
Research carried out in the Netherlands found that using HPV testing as the first line screening test, and smear testing for women who have a positive HPV result, could improve the performance of an HPV test for cervical screening.
The study, published in this week’s British Journal of Cancer, is based on results from 26,000 women who were given both smear and HPV tests as a way of determining how best to use HPV testing for cervical screening.
Previous studies showed that HPV testing is not particularly effective at spotting severe cervical cell changes and questions remained about how an HPV based programme should be implemented.
So this investigation looked at how likely women with different combinations of test results were to have severe cervical cell changes, known as CIN3.
They concluded that combining the two tests would not only mean women with the highest risks of having CIN3 were referred for further tests, it would also reduce unnecessary examinations.
Under their proposed screening process, women with a negative HPV test had an extremely low risk of CIN3, regardless of their smear test result, and so could safely return to routine screening every five years, claimed the authors.
Women with a positive HPV test, and whose smear test results showed abnormal changes in the cervix, had a 42 per cent chance of having CIN3, so would benefit from a colposcopy for more detailed analysis.
But if smear test results in HPV positive women were normal, the woman had a five per cent risk of CIN3. A follow-up smear after 12 months to monitor the cell changes would be needed, added the researchers.
Dr Chris Meijer, study author, based at the VU University Medical Centre in Amsterdam, said: “From a health-economic perspective cervical screening with a primary, stand-alone HPV test seems to be preferable based on this study.
“But a smear test is still a very useful way to estimate a woman’s risk of severe cervical changes and can help maximise the benefits of HPV testing in a cervical screening programme.”
Sara Hiom, director of information at Cancer Research UK, said: “This study provides a very useful insight into how HPV testing could work if it were used as a major part of cervical screening. The findings help answer some of the questions that would need to be considered should the UK refine its highly effective cervical screening programme.”
* In a second paper, published by the British Medical Journal today, Swedish researchers said women can boost substantially their chances of surviving cervical cancer by having regular cervical screening.
The study by scientists at the Centre for Research and Development in Gävle and the Karolinska Institutet, Stockholm, is the first to estimate chances of surviving cervical cancer.
They studied 1,230 women diagnosed with cervical cancer between 1999 and 2001 to establish if the detection of cervical cancer by screening resulted in better prognosis or resulted in earlier diagnosis, without postponing the time of death.
For women of screening age there was a 92 per cent cure rate after a screen-detected diagnosis, which decreased to 66 per cent for symptomatic diagnosis.
The chances of cure were also higher for women who attended screening following an invitation, compared to those who were overdue for an examination. Three quarters of the 373 women who died from cervical cancer had not had a smear in the recommended time frame.
Rijkaart, DC et al., HPV DNA testing in population-based cervical screening (VUSA-Screen study): results and implications British Journal of Cancer (2012) DOI: 10.1038/bjc.2011.581
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