biostudies-literatureMilgrom ZZU.S. National Library of MedicineLilly Endowment2883-2894https://www.ebi.ac.uk/biostudies/studies/S-EPMC9904246biostudies-literatureUnknown30(5)<h4>Background</h4>Measures taken to address the COVID-19 pandemic interrupted routine diagnosis and care for breast cancer. The aim of this study was to characterize the effects of the pandemic on breast cancer care in a statewide cohort.<h4>Patients and methods</h4>Using data from a large health information exchange, we retrospectively analyzed the timing of breast cancer screening, and identified a cohort of newly diagnosed patients with any stage of breast cancer to further access the information available about their surgical treatments. We compared data for four subgroups: pre-lockdown (preLD) 25 March to 16 June 2019; lockdown (LD) 23 March to 3 May 2020; reopening (RO) 4 May to 14 June 2020; and post-lockdown (postLD) 22 March to 13 June 2021.<h4>Results</h4>During LD and RO, screeAnnals of surgical oncologyBreast Cancer Screening, Diagnosis, and Surgery during the Pre- and Peri-pandemic: Experience of Patients in a Statewide Health Information Exchange.PMC9904246LILLY END/20091568000T15LM012502Hui SLFisher CSMilgrom DPHaggstrom DAMilgrom ZZMendonca EAHan YfalseBreast Cancer Screening, Diagnosis, and Surgery during the Pre- and Peri-pandemic: Experience of Patients in a Statewide Health Information Exchange.<h4>Background</h4>Measures taken to address the COVID-19 pandemic interrupted routine diagnosis and care for breast cancer. The aim of this study was to characterize the effects of the pandemic on breast cancer care in a statewide cohort.<h4>Patients and methods</h4>Using data from a large health information exchange, we retrospectively analyzed the timing of breast cancer screening, and identified a cohort of newly diagnosed patients with any stage of breast cancer to further access the information available about their surgical treatments. We compared data for four subgroups: pre-lockdown (preLD) 25 March to 16 June 2019; lockdown (LD) 23 March to 3 May 2020; reopening (RO) 4 May to 14 June 2020; and post-lockdown (postLD) 22 March to 13 June 2021.<h4>Results</h4>During LD and RO, scree2023-01-01T00:00:00Z2023 May2025-04-25T18:30:18.244Z2025-04-06T07:34:05.472ZS-EPMC99042463674950410.1245/s10434-023-13119-w