Could HPV testing on self-collected samples be routinely used in an organised cervical screening program? A modelled analysis.

Smith, Megan A; Hall, Michaela T; Saville, Marion; Brotherton, Julia Ml; Simms, Kate T; Lew, Jie-Bin; Bateson, Deborah; Skinner, S Rachel Rachel; Kelaher, Margaret; Canfell, Karen

BACKGROUND Cervical screening on self-collected samples has mainly been considered for targeted use in under-screened women. Updated evidence supports equivalent sensitivity of PCR-based HPV testing on self-collected and clinician-collected samples. METHODS Using a well-established model, we compared the lifetime impact on cancer diagnoses and deaths resulting from cervical screening using self-collected samples only, with and without the existing restriction in Australia to women aged 30+ and 2+ years overdue; compared to the mainstream program of 5-yearly HPV screening on clinician-collected samples starting at 25. We conservatively assumed sensitivity of HPV testing on self-collected relative to clinician-collected samples was 0.98. Outcomes were estimated either in the context of HPV vaccination ("routinely-vaccinated cohorts"; uptake as in Australia), or the absence of HPV vaccination ("unvaccinated cohorts"). RESULTS In unvaccinated cohorts, the health benefits of increased participation from self-collection outweighed the worst-case (2%) loss of relative test accuracy even if only 15% of women who would not otherwise attend used it ('additional uptake'). In routinely-vaccinated cohorts, population-wide self-collection could be marginally (0.2-1.0%) less effective at 15% additional uptake, but 6.2-12.4% more effective at 50% additional uptake. Most (56.6-65.0%) of the loss in effectiveness in the restricted self-collection pathway in Australia results from the requirement to be 2+ years overdue. CONCLUSIONS Even under pessimistic assumptions, any potential loss in test sensitivity from self-collection is likely outweighed by improved program effectiveness resulting from feasible levels of increased uptake. IMPACT Consideration could be given to offering self-collection more widely, potentially as an equal choice for women.