Impact of the COVID-19 pandemic on reported cancer diagnoses in Bavaria, Germany.

PURPOSE: The aim of our study was to explore the impact of the COVID-19 pandemic on reported cancer cases in Bavaria, Germany, by comparing pre-pandemic (March 2019 to February 2020) and pandemic period (March 2020 to February 2021).

METHODS: Data on incident cases were retrieved from the Bavarian Cancer Registry (until 22nd April 2022). We included patients with malignant and in situ neoplasms reported by pathology departments with consistent reporting. We calculated the number of incident cases during the COVID-19 pandemic and the pre-pandemic period with 95% confidence intervals (CI) with Bonferroni correction (α = 0.0018) based on a Poisson approach. We stratified for malignancy (malignant, in situ), tumor site, and month of year.

RESULTS: Data was available for 30 out of 58 pathology departments (51.7%) from Bavaria. Incident malignant neoplasms dropped from 42,857 cases in the pre-pandemic period to 39,980 cases in the pandemic period (- 6.7%; 95% CI - 8.7%, - 4.7%). Reductions were higher for colon, rectum, skin/melanoma as well as liver (> 10.0% reduction) and less for breast cancer (4.9% reduction). No case reductions were observed for pancreas, esophagus, ovary, and cervix. Percent changes were largest for April 2020 (- 20.9%; 95% CI - 24.7%, - 16.8%) and January 2021 (- 25.2%; 95% CI - 28.8%, - 21.5%) compared to the previous year. Declines tended to be larger for in situ compared to malignant neoplasms.

CONCLUSION: Detection and diagnosis of cancer were substantially reduced during the COVID-19 pandemic. Potential effects, e.g. a stage shift of tumors or an increase of cancer mortality, need to be monitored.