No abstract

Background In 2007, Australia was one of the first countries to introduce a national human papillomavirus (HPV) vaccination programme, and it has since achieved high vaccination coverage across both sexes. In December, 2017, organised cervical screening in Australia transitioned from cytology-based screening every 2 years for women aged from 18-20 years to 69 years, to primary HPV testing every 5 years for women aged 25-69 years and exit testing for women aged 70-74 years. We aimed to identify the earliest years in which the annual age-standardised incidence of cervical cancer in Australia (which is currently seven cases per 100 000 women) could decrease below two annual thresholds that could be considered to be potential elimination thresholds: a rare cancer threshold (six new cases per 100 000 women) or a lower threshold (four new cases per 100 000 women), since Australia is likely to be one of the first countries to reach these benchmarks. MethodsIn this modelling study, we used Policy1-Cervix-an extensively validated dynamic model of HPV vaccination, natural history, and cervical screening-to estimate the age-standardised incidence of cervical cancer in Australia from 2015 to 2100. We incorporated age-specific coverage of the Australian National HPV Vaccination Program in girls, including the catch-up programme, and the inclusion of boys into the vaccine programme from 2013, and a change from the quadrivalent to the nonavalent vaccine from 2018. We also modelled the effects of the transition to primary HPV screening. We considered two scenarios for future screening recommendations regarding the cohorts who will be and who have been offered the nonavalent vaccine: either that HPV screening every 5 years continues, or that no screening would be offered to these women. FindingsWe estimate that, in Australia, the age-standardised annual incidence of cervical cancer will decrease to fewer than six new cases per 100 000 women by 2020 (range 2018-22), and to fewer than four new cases per 100 000 women by 2028 (2021-35). The precise year of attaining these rates is dependent on the population used for age-standardisation, HPV screening behaviour and test characteristics, the incremental effects of vaccination of men on herd immunity in women, and assumptions about the future frequency of benign hysterectomies. By 2066 (2054-77), the annual incidence of cervical cancer will decrease and remain at fewer than one case per 100 000 women if screening for HPV every 5 years continues for cohorts who have been offered the nonavalent vaccine, or fewer than three cases per 100 000 women if these cohorts are not screened. Cervical cancer mortality is estimated to decrease to less than an age-standardised annual rate of one death per 100 000 women by 2034 (2025-47), even if future screening is only offered to older cohorts that were not offered the nonavalent vaccine.Interpretation If high-coverage vaccination and screening is maintained, at an elimination threshold of four new cases per 100 000 women annually, cervical cancer c...

Australia Postgraduate Award PhD Scholarship, Translational Cancer Research Network Top-up scholarship (supported by Cancer Institute NSW) and Cancer Council NSW.

Background Colorectal cancer screening programmes worldwide have been disrupted during the COVID-19 pandemic. We aimed to estimate the impact of hypothetical disruptions to organised faecal immunochemical test-based colorectal cancer screening programmes on short-term and long-term colorectal cancer incidence and mortality in three countries using microsimulation modelling. Methods In this modelling study, we used four country-specific colorectal cancer microsimulation models-Policy1-Bowel (Australia), OncoSim (Canada), and ASCCA and MISCAN-Colon (the Netherlands)-to estimate the potential impact of COVID-19-related disruptions to screening on colorectal cancer incidence and mortality in Australia, Canada, and the Netherlands annually for the period 2020-24 and cumulatively for the period 2020-50. Modelled scenarios varied by duration of disruption (3, 6, and 12 months), decreases in screening participation after the period of disruption (0%, 25%, or 50% reduction), and catch-up screening strategies (within 6 months after the disruption period or all screening delayed by 6 months). Findings Without catch-up screening, our analysis predicted that colorectal cancer deaths among individuals aged 50 years and older, a 3-month disruption would result in 414-902 additional new colorectal cancer diagnoses (relative increase 0•1-0•2%) and 324-440 additional deaths (relative increase 0•2-0•3%) in the Netherlands, 1672 additional diagnoses (relative increase 0•3%) and 979 additional deaths (relative increase 0•5%) in Australia, and 1671 additional diagnoses (relative increase 0•2%) and 799 additional deaths (relative increase 0•3%) in Canada between 2020 and 2050, compared with undisrupted screening. A 6-month disruption would result in 803-1803 additional diagnoses (relative increase 0•2-0•4%) and 678-881 additional deaths (relative increase 0•4-0•6%) in the Netherlands, 3552 additional diagnoses (relative increase 0•6%) and 1961 additional deaths (relative increase 1•0%) in Australia, and 2844 additional diagnoses (relative increase 0•3%) and 1319 additional deaths (relative increase 0•4%) in Canada between 2020 and 2050, compared with undisrupted screening. A 12-month disruption would result in 1619-3615 additional diagnoses (relative increase 0•4-0•9%) and 1360-1762 additional deaths (relative increase 0•8-1•2%) in the Netherlands, 7140 additional diagnoses (relative increase 1•2%) and 3968 additional deaths (relative increase 2•0%) in Australia, and 5212 additional diagnoses (relative increase 0•6%) and 2366 additional deaths (relative increase 0•8%) in Canada between 2020 and 2050, compared with undisrupted screening. Providing immediate catch-up screening could minimise the impact of the disruption, restricting the relative increase in colorectal cancer incidence and deaths between 2020 and 2050 to less than 0•1% in all countries. A post-disruption decrease in participation could increase colorectal cancer incidence by 0•2-0•9% and deaths by 0•6-1•6% between 2020 and 2050, compared with undisrupted screening. Interp...