Objectives Over the past decades, the incidence of malignant melanoma has multiplied, while the mortality has been relatively stable. Increased incidence and stable mortality may indicate some degree of overdiagnosis. Overdiagnosis can be defined as a diagnosis of a condition that would never cause symptoms, harm, or death had the condition remained undiagnosed and untreated. .

We aimed to systematically identify and review published empirical evidence about overdiagnosis in malignant melanoma.

Inclusion Criteria.

Empirical studies that examined or discussed overdiagnosis, in accordance with the abovementioned definition, in malignant melanoma were eligible. Eligible studies included qualitative and quantitative study designs unrestricted of publication type, population, and geographical location.

Methods Our scoping review adhere to The JBI methodology and PRISMA-ScR guideline. We developed the search strategy in cooperation with an information specialist. We searched five databases and screened reference lists from studies on full text level for additional studies. Two reviewers independently screened titles, abstracts and full texts for inclusion, and extracted data from the included studies.

Results Our search resulted in 1134 potentially relevant studies. We identified 35 empirical studies examining overdiagnosis in malignant melanoma: 29 register studies, three cohort studies, one case-control study, one survey study and one randomised controlled trial. Most register studies examined trends in melanoma incidence and/or mortality and found an increased incidence with a little or no change in mortality. The cohort studies and the case-control study showed that skin screening was associated with increased detection of melanoma, mostly in thin and in situ melanomas. Studies also showed that there is an association between the number of biopsies and melanoma diagnoses.Three studies estimated the degree of overdiagnosis; one cohort study and two register studies. The estimates ranged from 29% to 60%.

Conclusions Epidemiological data suggest a high degree of overdiagnosis in malignant melanoma, and thus establishes overdiagnosis as a phenomenon relevant in malignant melanoma. Clinicians should keep this in mind when weighing the benefits and harm of skin screening. We need high-quality evidence on the degree of overdiagnosis in malignant melanoma. This is of special importance in screening for malignant melanoma, which we recommend should not occur outside of randomised controlled trials. Intervention studies on how to prevent overdiagnosis in malignant melanoma are also needed.