Transitioning from cytology-based screening to HPV-based screening at longer intervals: implications for resource use

Area of Science:

• Public health
• Epidemiology
• Gynecologic oncology

Background:

• Australia is transitioning from two-yearly cytology to five-yearly primary HPV screening.
• This shift involves partial genotyping and triage for HPV 16/18 and other oncogenic types.
• The transition to a longer screening interval will cause initial fluctuations in test volumes.

Purpose of the Study:

• To quantify the impact of the cervical screening transition on screening and follow-up test volumes.
• To model year-to-year fluctuations in test and procedure volumes during the transition period.
• To assess the influence of HPV vaccination on screening outcomes.

Main Methods:

• A detailed simulation model estimated women screened and test volumes from 2015 to 2032.
• The model incorporated varying screening and HPV vaccination exposure in birth cohorts.
• It simulated the impact of the 2017 screening program switch on routine screening and abnormal cases.

Main Results:

• Screening and HPV test volumes are predicted to fluctuate by over +/-50% initially, stabilizing to +/-25% by the third 5-year period.
• Fluctuations in secondary tests and procedures are less pronounced, decreasing from +25%/-31% to +8%/-10%.
• HPV vaccination is projected to counteract increases in high-grade cytology, colposcopies, and precancer treatments, with treatments dropping below 2015 levels.

Conclusions:

• Initial fluctuations in screening and HPV test volumes are expected due to the longer interval.
• Follow-up tests and procedures will experience less fluctuation but significantly impact operational aspects.
• Detailed modeling provided crucial insights into the operational effects of the screening program switchover.