Regular HPV testing should be adopted as the primary screening tool for cervical cancer in women over 30, say the authors of a major clinical trial.
In results that suggest a reversal of the approach currently being rolled out in England, the authors said cytology should only be conducted if a sample tests positive for HPV.
The trial randomly assigned 45,000 Dutch women to liquid cytology or HPV DNA testing plus cytology. Five years later both groups were tested both by liquid cytology and the HPV test.
In the second round of screening, CIN lesions of grade 3 or worse were found to be less common in the group who were initially given the HPV test (relative risk 0.73). The combined test also detected more intermediate (grade 2) lesions than smear tests alone.
In the second round, no cases of cervical cancer were detected in women initially screened by HPV DNA testing, but nine were found in those who had been tested only by cytology in the first round.
The authors also concluded HPV tests in younger women would not lead to false positives. ‘Our results suggest that, with the triage algorithm used in this trial, HPV DNA testing in women aged 29-33 does not result in excessive diagnosis or lesions destined to regress, and lends support to the implementation of HPV DNA testing in programmed cervical screening starting at age 30 years.'
In England, the NHS is rolling out the HPV DNA test for women whose smear tests suggest low-grade or borderline pre-cancerous changes following successful pilots, but the test is yet to be implemented nationwide.
However, study author Professor Jack Cuzick, an epidemiologist at Queen Mary, University of London, said HPV testing offered a ‘greater degree of protection' and should be used for pre-cancer testing.
He said: ‘This is the second study to show that including HPV testing as the main screening method not only improves detection of precancerous changes, but also cuts cancer rates.'
‘In the UK, HPV testing is only recommended for women whose smear tests have shown borderline or "low grade" pre-cancerous changes to cervical cells. But based on the latest evidence, the HPV test would be the most effective way to detect cervical abnormalities in all women over 30.'
‘We would still take a liquid sample, but use the HPV test as the primary screening tool. Only if the HPV test is positive would you then also do cytology,' he added.
‘There have been three studies done in the UK, all of which have shown a much greater degree of protection with HPV testing.'