Aims
To estimate risk thresholds for identifying Australians at elevated risk of invasive melanoma and quantify the population potentially eligible for inclusion in a risk-stratified melanoma screening program.
Methods
A population-based microsimulation study generated a weighted synthetic cohort of 500,000 individuals representing Australians aged ≥18 years using Australian Bureau of Statistics age-, sex-, and state-specific population data. Previous melanoma history was assigned using Australian Institute of Health and Welfare age- and sex-specific prevalence estimates. Melanoma risk assessment was performed among individuals aged 40-74 years without a prior melanoma diagnosis using the QIMR Berghofer Melanoma Risk Calculator, originally developed for adults aged 40-69 years from the QSkin Study of Sun and Health (QSkin) cohort (n>43,000). Population distributions for risk factors were obtained from national Australian datasets where available, with additional melanoma-specific predictors parameterised from QSkin. Probabilistic sensitivity analysis comprising 1,000 Monte Carlo simulations was performed for QSkin-derived predictors.
Results
The modelled population represented approximately 21.4 million Australian adults, including 10.8 million individuals aged 40-74 years eligible for melanoma risk assessment. Risk threshold estimates were highly stable across simulations. The median 10-year absolute risk thresholds were 1.3%, 1.8%, and 2.4% for the 80th, 90th, and 95th percentile of the assessable population, respectively. Applying those thresholds identified approximately 2.1 million, 1.1 million, and 530,000 Australians at elevated melanoma risk. Approximately 130,000 Australians with a previous melanoma history were automatically eligible for screening. The resulting screening populations were comparable in scale to existing Australian cancer screening programs.
Conclusions
Application of the validated QIMR Berghofer Melanoma Risk Calculator generated the first national estimates of eligibility for risk-stratified melanoma screening in Australia. Depending on the selected threshold, approximately 0.7-2.3 million Australians could be eligible for screening. These findings provide an evidence base for planning a National Targeted Melanoma Screening Program and future economic and implementation evaluations.