Addition Of HPV Test To UK Cervical Screening Programme No Better At Detecting Cervical Cancer

Main Category: Cervical Cancer / HPV Vaccine
Article Date: 19 Jun 2009 - 2:00 PDT

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Combining human papillomavirus (HPV) testing with routine liquid-based cytology (LBC) screening does not increase the detection of cervical cancer compared with LBC screening alone, according to an Article published Online first and in the July edition of The Lancet Oncology.

A liquid form of the Pap smear test-liquid-based cytology-has replaced the conventional Pap smear test in the UK and has been shown to improve detection of precancerous cervical cells called cervical intraepithelial neoplasia (CIN), and to reduce the number of unsatisfactory samples that require retesting. Previous research has also found that testing for HPV in the cervix is more sensitive than conventional Pap smears and can detect CIN that smears miss, but also results in more false positives than conventional smears.

The current programme of cervical smear testing with LBC in the UK prevents around 70% of cancers. But it is not known whether adding HPV testing to routine cervical screening could increase the effectiveness of the screening programme in the UK.

To investigate, Henry Kitchener and colleagues conducted the ARTISTIC trial, the first randomised trial to compare combined LBC plus HPV testing with LBC alone in primary cervical screening. In total, 24,510 women aged 20-64 years attending general practice or family-planning clinics in Greater Manchester, UK, for routine cervical screening as part of the national screening programme were also tested for HPV. The women were randomly assigned in a ratio of 3-1 to either have their HPV result revealed and acted upon* (18,386 women: revealed group) or concealed from both the woman and the investigator (6,124 women: concealed group).

All the women were followed up and screened at 3 years to determine whether, as a result of the HPV testing, the revealed arm had fewer precancers because of improved detection and previous treatment of underlying lesions.

Overall, combined testing with LBC and HPV did not detect more high-grade lesions than LBC alone. Findings showed that in the first screening round HPV testing did detect cases of CIN grade 3 or worse (CIN3+) that were missed by LBC alone, but there were fewer cases detected in the combined screening arm in the second round, and over both screening rounds there was no significant difference between the two groups.

In the first round of screening 233 women (1.27%) in the revealed group had CIN3+, compared with 80 women (1.31%) in the concealed group. In the second round of screening the number of women with CIN3+ dropped to 29 women (0.25%) in the revealed group and 18 women (0.47%) in the concealed group. When both rounds were combined there was no statistically significant difference in the proportion of women found to have CIN3+ which were 1.5% in the revealed group and 1.77% in the concealed group.

The authors say that: "Over two rounds this trial showed no evidence that LBC combined with HPV testing in primary cervical screening detected more CIN2 or CIN3+ than cytology alone. This summed effect over two rounds is relevant because screening relies on repeated rounds to achieve its sensitivity."

The ARTISTIC trial will continue through to a third round of screening 6 years after enrolment, which the authors say will: "Determine whether HPV testing could extend screening intervals because of the longer duration of protection conferred by a negative HPV result than with a negative LBC finding."

Source
The Lancet Oncology