Impact of the COVID-19 pandemic on cancer diagnoses, oncological care and cancer patients in Germany: a report from the "COVID & Cancer" workshop 2023 of the German Society for Epidemiology (DGEpi).

Purpose: The COVID-19 pandemic was associated with severe disruptions in healthcare worldwide. Cancer patients are at particular risk of adverse consequences from delays in diagnosis and treatment. To evaluate the available data on the impact of the pandemic on cancer diagnoses, oncological care and patient well-being in Germany, the German Society for Epidemiology (DGEpi) in collaboration with the Epidemiological Cancer Registry of Lower Saxony invited to a workshop on "COVID & Cancer" (held on 26-27 October 2023 in Hanover, Germany). This report provides a summary of the scientific presentations, highlights methodological challenges, and recognises essential evidence gaps.

Methods: Twelve studies addressing various aspects in relation to cancer diagnoses, oncological care and patient well-being during the COVID-19 pandemic in Germany and two talks sharing experiences from the UK and the Netherlands were presented at the workshop.

Results and conclusions: Results from German cancer registries consistently showed lower number of incident cancer diagnoses among adults during the first months of the pandemic compared to the respective months of the years before the pandemic. Data from the cancer registries of Baden-Württemberg and Lower Saxony found especially for breast cancer a notable drop (by approximately one third) in the numbers of diagnoses during the first restriction period (April-May 2020), during which the nationwide mammography screening programme in Germany was temporarily suspended. Overall, the extent and ways, in which the pandemic had adversely affected cancer diagnoses, oncological care and created service backlogs, is still not adequately understood. The long-term consequences are yet to be determined.