Cytological screening prevents cervical cancer by early detection, resulting in treatment of precancerous cervical lesions. However, the sensitivity of a single cytology test is only around 60%¹ and randomized clinical trials have demonstrated that HPV testing has higher sensitivity than cytology, resulting in that HPV-based cervical screening is now globally recommended for women ≥30 years of age.^2,3 Detection of HPV E6/E7 mRNA is an alternative target for cervical screening tests as it marks transcriptionally active HPV infections with improved specificity for clinically relevant infections.⁴ Assessing equivalence for an HPV mRNA test to that of the established HPV DNA tests that were used in the randomized clinical trials requires longitudinal evaluation over at least the length of a screening interval.⁴

In order to analyse the longitudinal performance of HPV mRNA to that of an HPV DNA test, we used cervical samples (stored at -80°C) from 95,023 women participating in cervical cancer screening in Sweden between May 2007 to January 2012.⁵ Registry linkages identified that 599 of these women were ≥30 years of age when the cervical sample was stored, and had cervical intraepithelial neoplasia grade 3 or worse (CIN3+) diagnosed 4 months to 7 years after enrolment. We analysed the stored cervical samples for presence of both HPV mRNA (Aptima, Hologic) and for HPV DNA (Cobas 4800, Roche). Overall, presence of HPV infections was detected at similar rates for HPV mRNA (81.1%) and HPV DNA (83.8%) assays up to 7 years before CIN3+ (Table 1). Restricting analyses to CIN3+ lesions developing 5-7 years after sampling also found comparable longitudinal sensitivities for HPV mRNA (76.3%) and HPV DNA (82.5%) (Table 1).

In analyses of the risk to develop CIN3+ after a negative test, there was no significant difference between the two HPV assays up to seven years after the negative HPV-test result (Figure 1).

Women with HPV-negative results have a low rate of severe lesions over a screening interval of at least 5 years. The negative predictive values for the HPV mRNA and HPV DNA assays for absence of CIN3+ between 5-7 years after negative test results were estimated using data from ongoing primary HPV screening programs in 2 regions in Sweden (Stockholm region that uses Cobas, 9% HPV prevalence, and Skåne region that uses Aptima, 7% HPV prevalence) (Figure 2). We estimated similar high longitudinal negative predictive values for absence of severe lesions for negative HPV mRNA (99.97%, 95% CI: 99.95-99.98) and HPV DNA (99.98%, 95% CI: 99.96-99.99) test results.5 Recently Iftner et al. also reported a high negative predictive value (99.7%, 95% CI: 99.4 to 99.8) for the Aptima assay among women followed over 6 years.⁶

In summary, we found that HPV mRNA testing has similar longitudinal sensitivity as that of HPV DNA for detection of severe lesions. In addition we estimated similar high longitudinal negative predictive values for absence of severe lesions for negative HPV mRNA and HPV DNA test results over a screening period of 5-7 years. Our findings show that HPV mRNA testing can safely be used for primary cervical screening, which could have implications for improved global public health by allowing more precise and specific screening for prevention of cervical cancer.

References

1. Cong X, Cox DD, Cantor SB. Bayesian Meta-Analysis of Papanicolaou Smear Accuracy. Gynecol Oncol 2007;107:S133–7. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2964866/
2. Anttila A, Arbyn M, De Vuyst H, et al. European guidelines for quality assurance in cervical cancer screening [Internet]. Second. Luxembourg: Publications Office of the European Union; 2015 [cited 2019 Mar 22]. Available from: http://bookshop.europa.eu/uri?target=EUB:NOTICE:EW0115451:EN:HTML
3. Dillner J, Rebolj M, Birembaut P, et al. Long term predictive values of cytology and human papillomavirus testingin cervical cancer screening: joint European cohort study.BMJ 2008;337:a1754. Available from: https://www.bmj.com/content/337/bmj.a1754
4. Arbyn M, Snijders PJF, Meijer CJ, et al. Which high-risk HPV assays fulfil criteria for use in primary cervical cancer screening? Clin. Microbiol. Infect. 2015;21:817–26. Available from: https://www.clinicalmicrobiologyandinfection.com/article/S1198-743X(15)00426-7/pdf
5. Forslund O, Elfström KM, Lamin H, et al. HPV-mRNA andHPV-DNA detection in samples taken up to seven yearsbefore severe dysplasia of cervix uteri. International Journal of Cancer 2019;144:1073–81. Available from: https://onlinelibrary.wiley.com/doi/abs/10.1002/ijc.31819
6. Iftner T, Neis K-J, Castanon A, et al. Longitudinal Clinical Performance of the RNA-Based Aptima Human Papillomavirus (AHPV) Assay in Comparison to the DNA-Based Hybrid Capture 2 HPV Test in Two Consecutive Screening Rounds with a 6-Year Interval in Germany. J Clin Microbiol [Internet] 2019 [cited 2019 Mar 22];57. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6322477/