Cases of cervical cancer in Canada have decreased recently as a result of cytology-based screening programs. However, cervical cancer remains a relatively common and preventable cause of cancer in women. As cervical cancer is primarily caused by persistent genital infection with high-risk (HR) human papillomaviruses, Ontario Health has been evaluating implementing HPV-based testing in cervical screening.
As the type of HR-HPV test used in a cervical screen program can impact costs and resources, Aquarius Population Health developed a decision tree model to compare the use of the Aptima mRNA HR-HPV assay to a DNA HR-HPV assay in a hypothetical HPV primary screening algorithm in Ontario, Canada.
Results found for women aged 30-65 years screened in Ontario, using an mRNA versus a DNA HR-HPV assay would save over $4M CAD and avoid roughly 11,000 unnecessary colposcopies, 15,000 HPV tests and 40,000 cytology tests.
An HPV primary algorithm adapted from the Cervical Screening Programme (CSP) in England was simulated in a decision tree model, as it is comparable to the primary HPV algorithm proposed by the Cervical Screening Guideline Working Group in Ontario. In an HPV primary screening algorithm, cervical samples are first tested for HR-HPV. Positive HPV samples are then tested with cytology and referred to colposcopy if abnormal cells are found. Those with HPV positive results and negative cytology are recalled in 12 months for follow-up.
One cohort of 2.25 million women in Ontario aged between 30-65 years participating in cervical cancer screening was followed from baseline screen through recall visits. The model endpoint was discharge to routine recall, loss-to-follow-up, or referral to colposcopy. Costs were taken from the perspective of the Ontario Health System using published data. Probability data was taken from the FOCAL study; a head-to-head comparison of screening using HPV and cytology using DNA and mRNA tests in the Vancouver area.
This study explored the impact that the type of HPV test (mRNA versus DNA) could have within an HPV primary screening program. Robust study results indicate that the use of mRNA instead of DNA tests could save over $4 million annually, and avoid roughly 11,000 unnecessary colposcopies, 15,000 HPV tests and 40,000 cytology tests. As decision-makers in Canadian provinces and territories, including Ontario, consider implementing HPV primary screening, the choice of HR-HPV test is an important factor in avoiding unnecessary colposcopies and follow up testing. This benefits both healthcare providers and women with no impact on longer-term health outcomes.
Weston G, Dombrowski C, Steben M, et al. A health economic model to estimate the costs and benefits of an mRNA vs DNA high-risk HPV assay in a theoretical HPV primary screening algorithm in Ontario, Canada. Preventive Medicine Reports [Internet]. 2021;101448. Available from: https://www.sciencedirect.com/science/article/pii/S2211335521001388