Emerging from COVID-19 pandemic:Provider perspective on use of neoadjuvant endocrinetherapy (NET) in early stage hormone receptor positivebreast cancer

Introduction During the coronavirus 2019 (COVID-19) pandemic in USA, NET use has been recommended to allowsafe deferral of surgical treatment in early stage, estrogen receptor positive breast cancer (ER+BC) In suchcircumstances, after NET use there is limited guidance on locoregional treatment, especially with management of the axilla We aimed to evaluate patterns of care in early stage ER+BC during the first several months of theCOVID-19 pandemic Method A cross-sectional, 30-item survey was developed using a standardized surveydevelopment framework The survey was administered May 8 - June 12, 2020 to a convenience sample of medicaloncologists (MO), radiation oncologists (RO), and surgeons (SO) - breast committee members of two nationalcooperative groups (Alliance and SWOG) with additional participation through chain referrals Providers were presented with general questions on NET use before and during the pandemic They were asked their propensity foromitting axillary lymph node dissection (ALND) after NET if 1 micrometastatic node is found on sentinel lymph nodebiopsy, based on duration of NET Results 114 providers from 29 US states completed the survey - 42 (37%) MO, 14(12%) RO, and 58 (51%) SO, the majority (N=73/96, 76%) with practices dedicated ≥ 75% to BC, at NCI designatedcomprehensive cancer centers 52% (N=48/94) and in large cities (N=49/94, 52%) Prior to COVID-19, most rarely(N=49/107, 46%) or sometimes (N=36, 33%) used NET for early stage ER+BC Nearly half were willing to delay surgery up to 2 months (46%) and 3 months (21%) without use of NET (Table 1, p<0 05) Most providers wouldperform a genomic assay on the biopsy specimen on all or select patients prior to NET initiation, more frequently byMO compared to RO and SO (90% vs 75% and 60%, p<0 05) The most preferred regimen was tamoxifen (withoutovarian suppression) for premenopausal patients and aromatase inhibitor for postmenopausal patients Mostplanned to use NET for as little time as possible until surgery could proceed When stratified by specialty, more MOstated they would vary the duration of therapy based on patient's risk of cancer progression Most providersrecommended omitting ALND after 1, 2, or 3 months of NET (1 month N=56/93, 60%;2 months N=54/92, 59%;3months N=48/90, 53%) With longer duration of therapy, the propensity for omitting ALND decreased (definitely omitafter 6 months N=25/91, 27%;probably omit after 6 months N=38/91, 42%;definitely omit after 1 year N=26/92,28%;probably omit after 1 year N=29/92, 32%) Omitting ALND was not associated with provider's years in practice,percent of practice dedicated to BC, practice type or setting, participation in multidisciplinary tumor board, or numberof COVID-19 cases in the provider's practicing state ConclusionMost providers changed their management of early stage ER+BC during the COVID-19 pandemic by utilizing NET until surgery could proceed As the duration of NET extended, more providers favored ALND in low volume axillary metastatic disease in early stage ER+BC Additional data to inform the care on post-NET locoregional management is needed