Abstract P3-04-04: Multi-institutional perspective on screening mammography and breast cancer stage at diagnosis during the COVID-19 pandemic

Background: During the SARS-CoV-2 pandemic in 2020, the use of routine screening mammography (SM) and diagnostic mammography (DM) was limited for several months in order to reduce patient exposure and redeploy medical personnel. Previous studies suggest such delays result in more late-stage breast cancer diagnoses. We hypothesized that this impact would vary between institutions depending on regional variations in shutdown periods and the ability and willingness of patients to resume screening. Methods: Patients diagnosed with invasive breast cancers from 2016-2020 were identified using the Beth Israel Deaconess Medical Center (BIDMC) and the Duke University Medical Center (DUMC) cancer registries. Rates of mammography were ascertained from billing data. Baseline patient characteristics, demographics, and clinical information were gathered and cross-referenced with the electronic medical record. Late-stage was defined as Anatomic Stage III-IV disease (AJCC 8th edition). Chi-squared analysis was used to examine monthly distributions in stage at presentation for diagnosis in 2016-2019 compared to in 2020 at each institution. Results: There were 5907 patients diagnosed with invasive breast cancer between 2016-2019 (1597 at BIDMC and 4310 at DUMC) and 1075 in 2020 (333 and 742, respectively). Mammography was limited from 3/16/20-6/8/20 at BIDMC and from 3/16/20-4/20/20 at DUMC. There were fewer SM at each institution during their respective shutdown periods in 2020 than in the same months in 2019: BIDMC 1713 versus 8566 (80% reduction) and at DUMC 1649 versus 5698 (71% reduction). Following the pandemic shutdown, SM volume increased in July-December 2020 compared to July-December 2019 (108% at BIDMC and 116% at DUMC). The proportion of patients diagnosed with late-stage disease at BIDMC was greater in 2020 than in 2016-2019, at 12.6% and 6.6%, respectively (p < 0.001); 86% of late-stage diagnoses and 68% of all diagnoses in 2020 at BIDMC occurred from July-December following the initial shutdown period. The proportion of patients diagnosed with late-stage disease at DUMC in these two cohorts were 14.3% in 2020 and 16.2%% in 2016-2019 (p = 0.1); 50% of late-stage diagnoses and 51% of all diagnoses in 2020 at DUMC occurred in the period following the initial shutdown from July-December. Conclusion: We identified variation between two large academic medical centers in the impact of the SARS-CoV-2 pandemic shutdown on the proportion of late-stage breast cancer diagnoses. These dissimilar outcomes may be the result of differences in referral patterns as well as regional differences in the approach to SM during the pandemic. In particular, a shorter closure time and substantial increase in SM volume following the initial shutdown period in the Southeast region may have prevented an increase in late-stage diagnoses. Further information and analysis may help suggest additional strategies to minimize adverse effects of reduced cancer screening in future public-health emergencies. Table 1.Proportion of SM in 2020 compared to 2019 and proportion of late disease per month in 2020BIDMC 2020JanFebMarAprMayJunJulAugSepOct NovDecSM, %96109480034104106112105113112Late Disease, n(%)0 (0)2 (10)1 (3)0 (0)0 (0)3 (21)1 (7)9 (21)10 (15)10 (19)5 (12)1 (8)DUMC 2020JanFebMarAprMayJunJulAugSepOctNovDecSM, %565860040123111109127116120119Late Disease, n(%)12 (11)13 (19)14 (19)4 (18)4 (12)6 (11)12 (13)10 (13)6 (10)12 (19)7 (13)5 (13) Citation Format: Sarah J Stephens, Maxwell R Lloyd, Julian C Hong, Tejas Mehta, Ted A James, Rachel Blitzblau, Abram Recht, Daphna Y Spiegel. Multi-institutional perspective on screening mammography and breast cancer stage at diagnosis during the COVID-19 pandemic [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-04-04.