In 2017, the Dutch cervical cancer screening programme will switch from cytology testing to HPV testing as the primary screening method. HPV testing has been shown to earlier detect precursor lesions and provides better protection against cervical cancer. In addition, the screening interval for HPV negative women aged 40 years or more will be extended from five to ten years. This decision is based on the results of cost-effectiveness models. The Netherlands will be the first country with a ten-year screening interval.
Read more about the cervical cancer screening model.
Safety of extending the screening interval
There are concerns whether extending the screening interval will lead to more interval cancers, i.e. cancers that are symptomatically diagnosed between screening rounds. Therefore, this study, co-authored by Hans Berkhof, aimed to assess the risk of extending the screening interval beyond five years using data from the POBASCAM randomized controlled trial.
In the POBASCAM study, women aged 29-61 years were invited to participate in cervical cancer screening from January 1999 to September 2002. They were randomly assigned to either cytology and HPV co-testing (intervention group) or to cytology with blinded HPV testing (control group). Over 44,000 women participated in this trial. We used 14 year follow-up data from women with a negative HPV test or negative cytology. Our main outcome was the cumulative incidence of cervical cancer and cervical intraepithelial neoplasia (CIN) grade3+.
- In the intervention group, the cumulative incidence of cervical cancer and CIN3 was respectively 0.09% and 0.56% among HPV negative women after three screening rounds
- In the control group, figures were 0.09% and 0.69% after two screening rounds
- The incidence of CIN3+ was 72.2% lower among HPV negative women aged 40 years or older than among younger women. This difference was significant (95% CI 61.6%-79.9%)
- The incidence of CIN3+ was ten times higher in HPV positive women with a negative triage test compared to HPV negative women
This study showed that the risk of developing cervical cancer or CIN3+ is low in HPV negative women. Furthermore, the results support an extension of the screening interval from five to ten years for HPV negative women aged 40 years or older. However, the screening interval cannot be extended in HPV positive women with a negative triage test.
Read the full article ‘Safety of extending screening intervals beyond five years in cervical screening programmes with testing for high risk human papillomavirus: 14 year follow-up of population based randomised cohort in the Netherlands’