Evaluation of early skin cancer detection in Germany with cancer registry data - challenges, solutions and current trends.

Background And Aims: The evidence for the benefit of the skin cancer screening introduced in Germany in 2008 is weak. We investigate to what extent data from the German epidemiological cancer registries are suitable to contribute to the evaluation of skin cancer screening and report these evaluation results.

Material And Methods: Skin cancer-related cancer registry data from 1999-2019 were described in terms of completeness and comprehensiveness. Regional pools with data of different validity were defined, missing data were multiply imputed where appropriate, and temporal trends were analyzed. In addition, data from the cause of death statistics were used.

Results: Reliable estimates of completeness are only available for malignant melanoma (ICD-10: C43). Based on a regional data pool covering approximately 21% of the German population, melanoma-related incidence can be validly described since 2005. Sufficient information for multiple imputation is available for T-stage and localization. The trend analyses show incidence changes that can be expected in the short term in the temporal context of the introduction of early detection, which changes into a long-lasting high incidence. The rate of advanced stages does not decrease significantly. From 2014 onwards, the melanoma mortality rate, which had been rising until then, decreases.

Conclusions: Adequately selected and processed cancer registry data are suitable for population-based evaluation of skin cancer screening. An explanation of the persistently high incidence level is not possible based on the cancer registry data. Overdiagnosis or an increase in the background incidence can be considered. The benefit of skin cancer screening remains open.