In Italy, the cohorts of women who were offered HPV vaccination in 2007/08 will reach the age for cervical cancer (CC) screening in 2017. The simultaneous shift from cytology-based screening to HPV test-based screening gives the opportunity for unprecedented reorganisation of CC prevention. Despite a wide consensus about the need of adopting different screening protocols for vaccinated women, no guidelines yet recommend different screening strategies (systematic review updated in 2015).
The ONS (National Screening Monitoring Centre) Directive and the GISCi (Italian Group for Cervical Screening) identified the consensus conference as the most suitable method for defining the research needs in order to define the best protocols in vaccianted women (1). The ONS and GISCi set up a promoting committee and a Jury. The promoting committee identified a panel of experts representative of Italian scientific societies involved in CC prevention, who defined the scope questions and commissioned several systematic review and modelling studies in order to answer the following questions:
Do the protocols for screening programs need to be changed upon the arrival of the cohorts of vaccinated women?
If so, which policy: tailored strategy or one size fits all strategy.
At what age should screening start?
With which test?
How often?
Should the strategy be different for the cohorts vaccinated in their 15th year (or later) with respect to those vaccinated in their 12th year?
Which actions need to be scheduled from now?
According to a systematic review on long term vaccine accuracy and the estimate of cumulative incidence of non-16/18 cancers in pre-screening era in Italy, the number of cancer non-vaccine-preventable cancers in unscreened population below 30 is about 5 per year (10 with the most conservative models). The acceptable threshold now is the the numbers of cancer occurring below 25: this is 8 cancer per year in Italy.
The Jury considered changing the screening protocols for girls vaccinated in their 12th year as appropriate. Tailored screening protocols based on vaccination status could be replaced by “one size fits all” protocols only when a herd immunity effect has been reached. Vaccinated women should start screening at age 30, instead of 25, with HPV test. Furthermore, there is a strong rationale for applying longer intervals for re-screening HPV negative women than the currently recommended 5 years, but research is needed to determine the optimal intervals. For non-vaccinated women and for women vaccinated in their 15th year or later, the current protocol should be kept.
(1) Giorgi Rossi P, Carozzi F, Federici A, Ronco G, Zappa M, Franceschi S; Italian Screening in HPV vaccinated girls Consensus Conference group. Cervical cancer screening in women vaccinated against human papillomavirus infection: Recommendations from a consensus conference. Prev Med. 2017 May;98:21-30.