ABSTRACT
Background: The effects of the COVID-19 pandemic on incidence, stage distribution, primary therapy, and delay in therapy were analyzed for breast cancer, prostate cancer, colorectal cancer, bronchial cancer, lymphoma and leukemia. Method(s): The years 2020 versus 2019 were compared with focus on the months of the first wave of pandemics from February to May 2020 analyzing data from the clinical cancer registry Regensburg. Result(s): The total numbers of annual new cases were lower in all entities in 2020 vs. 2019. The percentage decrease ranged between -1.9% for breast cancer and -15.3% for colorectal cancer, with highly significant difference for colorectal cancer (p<0.001). The comparison of the monthly reported number of cases showed a decrease in all analyzed cancer entities, in March to May 2020 compared to 2019 with statistical significance. There was no significantly increased rate of patients with advanced stages III/IV, larger tumors T3/T4, positive node status or distant metastases in nearly all entities neither in the annual nor the monthly comparison. Colorectal cancer was an exception, with significantly increased rates in March and April 2020. Apart from bronchial cancer, rates of primary therapy in stages I-III in 2020 were mostly slight, but not significantly lower than in 2019. Significantly lower treatment rates were found for prostate cancer in March 2020 and for colorectal cancer in November 2020. The mean interval between diagnosis and start of therapy was the same or slightly longer in 2020, but not significant, except for lung cancer, leukemia and lymphoma. Discussion(s): A potential lack in transmitted medical informations, a delay of documentation and consequently restricted real-time analysis must be considered when using data from clinical cancer registries. Conclusion(s): A decreased incidence especially during the first wave could be shown. A shift of stage distribution and treatment delay was not observed. Follow-up analyses and observation of the subsequent pandemic waves are necessary to confirm the current results.