HPV HANDBOOK - Zervita

3: HPV AND CERVICAL CANCER: PUBLIC HEALTH PERSPECTIVESCIN 3 lesions or perhaps even cases of cervical cancer. Currently, HRHPV testing would be unacceptable as a primary screening method forcervical cancer in the absence of evidence that HR HPV-negative CIN3 lesions would regress, or at least not progress to cervical cancer.However, such evidence is difficult to obtain, for ethical reasons.Preliminary modelling studies have shown that the anticipatedreduction in mortality from cervical cancer that would result from HRHPV testing once every 5 years would be at least as high as that froma cervical smear test once every 3 years. However, as previouslystated, until data from population-based screening studies withcombined cytology and HR HPV testing are able to show that HR HPVnegativeCIN 3 lesions will regress, screening by HR HPV testing alonewill not be considered. In addition, a single HR HPV test is unable todetermine whether the infection is new or long-standing. This is animportant consideration, because it is the persistent HPV infectionsthat give rise to CIN 3.Advantages of adding HPV testing to cytology testingfor population-based screening programmes• Adding HPV to cytology testing improves the negativepredictive value from 96–97% to >99% 14• Women with BMD could be referred directly, on the basis ofthe presence of HR HPV, because high-grade lesions (≥CIN 3)are found only in HR HPV-positive women 7,8,15– Referrals would reduce by 10%– There would be less need for repeat smears at 6 and18 months• Only those women with normal cytology who are also HRHPV-positive (4% of the screened population) are at risk ofCIN 3/cervical carcinoma within 4 years, and require annualassessment by cytology and HR HPV testing– HR HPV-negative women with normal cytology (96% ofthe screened population) could be assessed every 8–10years30