ABSTRACT
Background: The COVID-19 pandemic has disrupted breast cancer control through shortterm declines in screening, delays in diagnosis and reduced/delayed treatments. We projected the impact of COVID-19 on future breast cancer mortality.Methods: Three established Cancer Intervention and Surveillance Modeling Network (CISNET) models projected the impact of pandemic-related care disruptions on breast cancer mortality between 2020 and 2030 vs. prepandemic care patterns. Based on Breast Cancer Surveillance Consortium data, we modeled reductions in mammography screening utilization, delays in symptomatic cancer diagnosis, and reduced use of chemotherapy for women with early-stage disease for the first six months of the pandemic with return to pre-pandemic patterns after that time. Sensitivity analyses were performed to determine the effect of key model parameters, including the duration of the pandemic impact. Results: By 2030, the models project 1,297 (model range: 1,054-1,900) cumulative excess deaths related to reduced screening;1,325 (range: 266-2,628) deaths from delayed diagnosis of symptomatic women, and 207 (range: 146-301) deaths from reduced chemotherapy use for early-stage cancer. Overall, the models predict 2,487 (range 1,713- 4,875) excess deaths, representing a 0.56% (range: 0.36%-0.99%) cumulative increase over deaths that would be expected by 2030 in the absence of the pandemic's disruptions. Sensitivity analyses indicated that the impact on mortality would approximately double if the disruptions lasted for a 12-month period. Conclusions: The impact of the initial pandemicrelated disruptions in breast cancer care will have a small long-term cumulative impact on breast cancer mortality. The impact of the initial pandemic-related disruptions on breast cancer mortality will largely be mitigated by the rapid return to usual care. As the pandemic continues it will be important to monitor trends in care and reassess the mortality impact. (Table Presented).