Abstract P1-05-19: Impact of the COVID-19 pandemic on the diagnostic pathway of breast cancer in the Netherlands: a population-based study
Authors: Wolfkamp Wouter , Meijer Joyce , Van Hoeve Jolanda , Veltman Jeroen , Siesling Sabine 
Published: March 2023

Abstract
Objective: The COVID-19 pandemic has had an impact on health care. In the Netherlands, hospital capacity for non-covid care was limited and population screening temporarily halted. The aim of this study was to investigate the impact of the pandemic on the diagnostic pathway of breast cancer.
Methods: In this study, 48,425 breast cancer patients with a primary breast tumour were selected from the Netherlands Cancer Registry and the Dutch Hospital Data. Patients diagnosed in period January 2020 to July 2021 were divided into six periods, based on the number of hospitalizations due to the COVID-19 pandemic and compared to the same periods in 2017-2019. A t-test was performed to compare the number of diagnosed patients per period. Patient characteristics were compared using chi-squared test. The impact on the procedures performed was analysed using logistic regression. The median time between diagnosis and therapy and the median time between first diagnostic procedure and therapy was analysed using Cox Proportional Hazards Regression. All results were corrected for age, stage and region.
Results: During the first peak of the pandemic in 2020, significantly fewer patients (-48,2%) have been diagnosed with breast cancer. This decrease is mainly seen in lower stage tumours. Mammography and echography were performed significantly less per patient during the first recovery in 2020 (OR=0.83 and OR=0.85 respectively) compared to 2017-2019. PET-CT was performed significantly more often during the first peak and first recovery in 2020 (OR=1.94 and OR=1.39 respectively). The median time between diagnosis and start of therapy significantly decreased in 2020, during the first peak by 3 days (HR=1.26), during first recovery and second peak by 1 day (HR=1.04 and HR=1.16 respectively). The median time between first diagnostic procedure and start of therapy significantly decreased in 2020, during the first peak by 4 days (HR=1.25), during the first recovery by 1 day (HR=1.04) and during the second peak by 2 days (HR=1.13).
Conclusion: The decreased number of diagnosis was related to the temporary halt of the screening. Diagnostics for early stage tumours was limited and for PET-CT was performed more often reflecting the change in proportion of higher stage. A reduced time of the diagnostic pathway is the result of less hospitalized patients with cancer and the effort on keeping the oncology care in place.
Table 1. Overview results diagnostic pathway of breast cancer. *significant difference between periods p&lt;0.05 **significant difference between periods p&lt;0.01
Citation Format: Wouter Wolfkamp, Joyce Meijer, Jolanda Van Hoeve, Jeroen Veltman, Sabine Siesling. Impact of the COVID-19 pandemic on the diagnostic pathway of breast cancer in the Netherlands: a population-based study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-05-19.