ABSTRACT
Background: The COVID-19 pandemic rapidly altered health care worldwide. To save protective equipment andminimize exposures, many hospitals stopped some or all cancer surgery, leading oncologic providers to quicklyadjust patient management. The goal of this study is to describe the breast cancer patient level changes whichoccurred during the initial months of COVID-19 in the United States. Methods: The American Society of BreastSurgeons developed a COVID-19 specific registry, within the established HIPPA compliant Mastery of BreastSurgery Program. Surgeons entered patient demographic data as well as their surgical and medical care(Neoadjuvant endocrine (NET) vs Neoadjuvant chemotherapy (NCT)). Data fields tracked whether decisions were usual for that practice, or modified due to COVID-19. Results: Between 3/1 and 6/17/2020, data from 1781 patients was entered by 154 surgeons. Mean age was 63, 78% Caucasian, 10% African American, 6% Hispanic;withgeographic distribution ranging from 10.8% Northwest to 29.5% Northeast. Initial consultation took place in-personfor 94.8% and only 5.2% (89) occurred via video/telephone. To date, just over 1% (14) of patients tested positive forCOVID-19. Mean invasive tumor size was 21.2mm and 15.7% were node positive. Of 1445 invasive breast cancers75% (1081) were ER +/HER2-, 13.5% (195) HER2+, 11.1% (160) triple negative (TNBC) (9/missing data). DCIScomprised 18.2% (325) of the cohort. Of 267 cases of ER+ DCIS, 49% (131) had primary surgery and 49% (130). received NET. The majority of NET use was due to COVID-19, 95% (124). Almost all (50/52) ER- DCIS underwentprimary surgery (6/missing ER). Table 1 describes the management for the 1436 patients with invasive cancer withknown biomarkers. NET due to COVID-19 was utilized in 45% (482), with only 5% (54) as part of usual practice.Increasing age was not a statistically significant factor in the use of NET (OR 0.99, 95% CI 0.97-1.01). Incomparison to patients from the Northwest, patients from the Southwest and Northeast had the greatest use of NET(COVID-19) vs NET(usual) (ORs 14.4 and 4.6) Genomic assay testing was performed on the core biopsy in 216patients, with 65% (141) due to COVID-19. Among the patients who had genomic testing due to COVID-19, 116(82%) had NET, 18 (13%) had NCT, with the remaining having primary surgery. Of 472 patients treated with primarysurgery for which the impact of COVID-19 was provided, surgery was delayed in 20% (96). Patients from theNortheast had a 2.1 x greater odds of having surgery delayed in comparison to those from the Midwest. Patientsalso experienced changes to their surgical plan with the most common changes being 6% (27) converting frommastectomy to breast conservation and 7% (34) from mastectomy with reconstruction to mastectomy withoutreconstruction. Conclusion: COVID-19 led to significant modifications in breast cancer treatment, including highrates of NET, genomic assay testing on core biopsies as well as delays in surgery;each of which were consistent with the prioritization and treatment recommendations from the COVID-19 Pandemic Breast Cancer Consortium.The majority of patients with TNBC and HER2+ disease received guideline concordant NCT. The ASBrS MasteryCOVID-19 registry provides a snapshot into the rapid care changes caused by the pandemic, has ongoing dataentry and analysis and will enable understanding of the impact on long term breast cancer outcomes.