Analysis of the methodology of skin cancer incidence registration in German cancer registries
Skin cancer is one of the most common cancers in the world but non-melanoma skin cancer (NMSC) has been included for the first time in the Global Cancer Incidence, Mortality and Prevalence (GLOBOCAN). Germany is one of the countries with high-quality data collected by 16 population-based cancer registries, yet NMSC always faced completion issues because of out-patient based treatment. The purpose of this study is to analyze the methodology of skin cancer incidence registration, assess the quality of data on skin cancer, and suggest improvements. The information was extracted from annual reports of all German cancer registries, the Robert Koch Institute (RKI), the Manual of cancer registration, through a questionnaire sent to all the registries and relevant articles. Comparison of the methodology with that of Nordic countries was done to suggest improvements. Legislative laws for remuneration, changing ICD codes, no multiple tumors counting, all affect skin cancer registration and its reported incidence rate. Use of mortality/incidence (M/I) ratio as an assessment of completeness, national skin cancer screening (SCS) project, the incomplete Tumor Node Metastasis (TNM) staging, determine the quality of skin cancer data. This data is definitely more complete for malignant melanoma (MM) as compared to NMSC. Nordic countries have achieved higher completion even for skin cancer data. Reporting basal cell cancer (BCC) in a separate file, recording the tumor stage and site specifications will improve the quality of data. Remuneration laws and rules for multiple tumors need to be reformed and standardized across all the federal states. Upcoming clinical cancer registries would complement the epidemiological registries and help improve the situation in the future in Germany.