Symposium
Women vaccinated for HPV16/18 are at reduced risk of infection. In addition, HPV 16 progresses more rapidly than the other genotypes to high grade CIN and plausibly to cancer. Thus, the prevalence of high-grade CIN is expected to be strongly reduced in HPV16/18 vaccinated women. The prevalence of cytological abnormalities is also expected to be reduced, but much less, because of abnormalities related to other high-risk types, to low-risk types or a-specific). In conclusion the positive predictive value (PPV) of cytology is expected to be strongly reduced. The PPV of HPV testing will also be reduced but much less. An Italian consensus conference was held in Florence in November 2015, based on systematic reivew of the literature prepared by a technical committee and on a jury including experts and stakeholders. The incidence of invasive cervical cancer in vaccinated women at younger ages was estimated based on a pooled analysis of the age-specific type distribution in younger women and cancer incidence data. The number of cancers not preventable by starting screening at age 30 in vaccinated women was lower than the number not preventable starting screening at age 25 in unscreened women. Thus the jury recommended to start screening in vaccinated women at age 30. The jury also recommended that vaccinated women are screened by HPV testing. It is clear that vaccinated women should be screened at longer intervals than the unvaccinated but there is not sufficient evidence to define how much longer. It was proposed to enrol cohorts of women vaccinated after age 12 (during initial catch-up) and HPV negative at age 25. The screening interval will be defined on the basis of the detection of CIN3 at age 30 and later. The jury recommended that these policies are initially applied just to vaccinated women but then to all vaccinated cohorts if vaccine coverage reaches sufficient levels to provide relevant herd immunity. A number of other related actions, for implementation were also recommended, particularly as for the linkage of the screening and vaccination registration systems