Background: Research suggests that a high proportion of melanoma in situ (MIS) may be overdiagnosed, potentially contributing to overtreatment, patient harm and inflated costs for individuals and healthcare systems. However, Australia-wide estimates of the magnitude of melanoma overdiagnosis are potentially outdated and there has been no estimation of the cost to the healthcare system.
Objectives: To estimate the magnitude and cost of overdiagnosed MIS and thin invasive melanomas in Australia.
Methods: Using two different methods to calculate lifetime risk, we used routinely collected national-level data to estimate overdiagnosed MIS and thin invasive melanomas (stage IA) in Australia in 2017 and 2021, separately for men and women. We multiplied the number of overdiagnosed melanomas by the estimated annual cost of a MIS or thin invasive melanoma, to quantify the financial burden of melanoma overdiagnosis to the Australian healthcare system in the year following diagnosis.
Results: We estimated that 67-70% of MIS were overdiagnosed in 2017, rising to 71-76% in 2021, contributing to between 19 829 [95% confidence interval (CI) 19 553-20 105] and 20 811 (95% CI 20 528-21 094) cases of overdiagnosed MIS. In 2021, the estimated costs in Australia ranged between $17.7 million Australian dollars (AUD; 95% CI 17.4-17.9 million) and AUD$18.6 million (95% CI 18.3-18.8 million). We estimated that 22-29% of thin invasive melanomas were overdiagnosed in 2017, rising to 28-34% in 2021, contributing to between 2831 (95% CI 2726-2935) and 3168 (95% CI 3058-3279) overdiagnosed thin invasive melanomas. In 2021, the estimated costs from thin invasive melanoma overdiagnoses ranged between AUD$2.5 million (95% CI 2.4-2.6 million) and AUD$2.8 million (95% CI 2.7-2.9 million).
Conclusions: Melanoma overdiagnosis is a growing clinical and public health problem in Australia, producing significant economic costs in the year following overdiagnosis. Limiting melanoma overdiagnosis may prevent unnecessary healthcare resource use and improve financial sustainability within the Australian healthcare system.
Over-diagnosis of melanoma (a type of skin cancer) can happen when someone has a spot that looks like melanoma but would not have caused any problems if it had not been found. Estimates of stage 0 melanoma (also called ‘melanoma in situ’) over-diagnosis in Australia and the USA range between 45% and 85%. There have been no estimates of the costs associated with this. We used nationwide data to find out the extent and cost of stage 0 and stage IA (also called ‘thin invasive melanoma’) overdiagnosis in Australia. We first calculated the lifetime risk of a melanoma diagnosis in 2004, 2017 and 2021. Next, we estimated the proportion of melanomas that are over-diagnosed. We also calculated the cost of over-diagnosis. We estimated that 67% to 70% of stage 0 melanomas were over-diagnosed in Australia in 2017, rising to 71% to 76% in 2021. The proportion of over-diagnosed stage IA melanoma was 22% to 29% in 2017, rising to 28% to 34% in 2021. Over-diagnosed melanomas cost the Australian healthcare system approximately $21.6 million in 2021. Our study findings suggest that melanoma overdiagnosis is a growing problem in Australia. This problem results in significant economic costs.
© The Author(s) 2024. Published by Oxford University Press on behalf of British Association of Dermatologists. All rights reserved. For commercial re-use, please contact [email protected] for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact [email protected].