HPV-based cervical cancer screening may be more effective than cytology

January 01, 0001

HPV-based cervical cancer screening may be more effective than cytology

The researchers from Italy and the UK assessed the efficacy of cervical-cancer screening policies that are based on HPV testing. Women aged 25- 60 years were randomly assigned to conventional cytology or to HPV testing in combination with liquid-based cytology (first phase) or alone (second phase). During phase one, women who were HPV-positive and aged 35-60 years were referred to colposcopy, whereas women aged 25-34 years were referred to colposcopy only if cytology was also abnormal or HPV testing was persistently positive. During phase two, women in the HPV group were referred for colposcopy if the HPV test was positive. Two rounds of screening occurred in each phase, and all women had cytology testing only at the second round. In total for both phases, 47,001 women were randomly assigned to the cytology group and 47,369 to HPV testing. 33,851 women from the cytology group and 32,998 from the HPV-testing group had a second round of screening.

The detection of invasive cervical cancers was similar for the two groups in the first round of screening (9 in the cytology group vs 7 in the HPV group, not significant). No cases were detected in the HPV group during round two, compared with nine in the cytology group (significant). Overall, in the two rounds of screening, 18 invasive cancers were detected in the cytology group versus seven in the HPV group (significant). Among women aged 35-60 years, at round one the relative detection (HPV vs cytology) was 2.00 for CIN2, 2.08 for CIN3, and 2.03 for CIN2 and 3 together. At round two the relative detection was 0.54 for CIN2, 0.48 for CIN3, and 0.51 for CIN2 and 3 together. Among women aged 25-34 years, there was significant heterogeneity between phases in the relative detection of CIN3. At round one the relative detection was 0.93 in phase one and 3.91 in phase two. At round two the relative detection was 1.34 in phase one and 0.20 in phase two. Pooling both phases, the detection ratio of CIN2 for women aged 25-34 years was 4.09 at round one and 0.64 at round two.

The researchers concluded: "HPV-based screening is more effective than cytology in preventing invasive cervical cancer, by detecting persistent high- grade lesions earlier and providing a longer low-risk period. However, in younger women, HPV screening leads to over-diagnosis of regressive CIN2."

For external generalizability, a lot will depend on the screening program already in place in other countries.

For the full abstract, click here.

The Lancet Oncology published online 19 January 2010
© 2010 Elsevier Ltd
Efficacy of human papillomavirus testing for the detection of invasive cervical cancers and cervical intraepithelial neoplasia: a randomised controlled trial. Guglielmo Ronco, Paolo Giorgi-Rossi, Francesca Carozzi for the New Technologies for Cervical Cancer screening (NTCC) Working Group. Correspondence to Guglielmo Ronco: guglielmo.ronco@cpo.it

Category: X. Female Genital System, Breast. Keywords: human papillomavirus, testing, screening, invasive, cervical cancer, cervical intraepithelial neoplasia, randomised controlled trial, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 5 March 2010

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