Abstract SS2-05: Emerging from COVID-19 pandemic: Provider perspective on use of neoadjuvant endocrine therapy (NET) in early stage hormone receptor positive breast cancer
Authors: Park Ko Un , Gregory Megan E , Lustberg Maryam B , Bazan Jose G , Shen Chengli , Rosenberg Shoshana M , Blinder Victoria S , Sharma Priyanka , Pusztai Lajos , Partridge Ann H , Thompson Alastair 
Published: February 2021

IntroductionDuring the coronavirus 2019 (COVID-19) pandemic in USA, NET use has been recommended to allow safe deferral of surgical treatment in early stage, estrogen receptor positive breast cancer (ER+BC). In such circumstances, 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 the COVID-19 pandemic.MethodA cross-sectional, 30-item survey was developed using a standardized survey development framework. The survey was administered May 8 - June 12, 2020 to a convenience sample of medical oncologists (MO), radiation oncologists (RO), and surgeons (SO) - breast committee members of two national cooperative 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 for omitting axillary lymph node dissection (ALND) after NET if 1 micrometastatic node is found on sentinel lymph node biopsy, based on duration of NET.Results114 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 designated comprehensive 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&lt;0.05). Most providers would perform a genomic assay on the biopsy specimen on all or select patients prior to NET initiation, more frequently by MO compared to RO and SO (90% vs. 75% and 60%, p&lt;0.05). The most preferred regimen was tamoxifen (without ovarian suppression) for premenopausal patients and aromatase inhibitor for postmenopausal patients. Most planned to use NET for as little time as possible until surgery could proceed. When stratified by specialty, more MO stated they would vary the duration of therapy based on patient’s risk of cancer progression. Most providers recommended omitting ALND after 1, 2, or 3 months of NET (1 month N=56/93, 60%; 2 months N=54/92, 59%; 3 months N=48/90, 53%). With longer duration of therapy, the propensity for omitting ALND decreased (definitely omit after 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 number of 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.

Table 1. Management of early stage, node negative, ER+BC during COVID-19 pandemicTotal (N, %)Med OncRad OncSurgeonHow long are you willing to delay surgery (without use of endocrine therapy)?Up to 1 month25 (23%)10 (24%)015 (26%)Up to 2 months51 (46%)17 (40%)7 (64%)27 (47%)Up to 3 months23 (21%)9 (21%)2 (18%)12 (21%)Up to 4 months3 (3%)2 (5%)1 (9%)0Up to 6 months8 (7%)4 (10%)1 (9%)3 (5%)Have you changed your practice during the current pandemic?Yes - institution mandated change to delay surgery8 (25%)4 (36%)04 (29%)Yes - based on multidisciplinary team discussion (no explicit institutional mandate to delay cancer surgery)21 (66%)6 (55%)7 (100%)8 (57%)No - was not allowed by institution to change0000No - was not necessary3 (9%)1 (9%)02 (14%)If using endocrine therapy before surgery, which regimen are you using?†Tamoxifen for all patients0000Tamoxifen for premenopausal patients; aromatase inhibitor for postmenopausal patients77 (81%)26 (63%)051 (94%)Ovarian suppression with aromatase inhibitor for premenopausal patients; aromatase inhibitor for postmenopausal patients18 (19%)15 (37%)03 (6%)How are you staging the axilla prior to starting endocrine therapy?Exam only28 (26%)8 (19%)2 (17%)18 (33%)Exam + US77 (71%)30 (71%)10 (83%)37 (67%)Exam + US + cross sectional image (CT scan)4 (4%)4 (10%)0 (0%)0 (0%)SLNB0000If using endocrine therapy first (before surgery), are you†Sending genomic assay on biopsy specimen on all patients28 (26%)18 (44%)1 (8%)9 (16%)Sending genomic assay on biopsy specimen on only select patients (ie. high grade, size on imaging/exam, high Ki-67)51 (48%)19 (46%)8 (67%)24 (44%)Not sending genomic assay. Using PEPI score instead.4 (4%)1 (2%)1 (8%)2 (4%)Not sending genomic assay. Using Magee Equations for Estimating Oncotype DX Recurrence Score instead.2 (2%)002 (4%)None of above21 (20%)3 (7%)2 (17%)18 (33%)If using endocrine therapy first, what duration do you plan to use it for the average patient?†Minimum 1 year for all patients0000Minimum 6 months for all patients7 (6%)4 (10%)0 (0%)3 (5%)Minimum 3 months for all patients19 (18%)7 (17%)1 (8%)11 (20%)As short as possible (less than 3 months), until it is safe to proceed with surgery in light of COVID-19 situation57 (53%)14 (34%)9 (75%)34 (62%)Duration of therapy depends on patient''s risk of cancer progression (ie. tumor grade, percent hormone positivity)25 (23%)16 (39%)2 (17%)7 (13%)If using endocrine therapy before surgery, do you plan to re-image the breast prior to surgery?†Yes, re-image all patients27 (25%)14 (34%)1 (8%)12 (22%)No8 (7%)0 (0%)2 (17%)6 (11%)Case by case basis72 (67%)27 (66%)9 (75%)36 (67%)

Citation Format: Ko Un Park, Megan E Gregory, Maryam B Lustberg, Jose G Bazan, Chengli Shen, Shoshana M Rosenberg, Victoria S Blinder, Priyanka Sharma, Lajos Pusztai, Ann H Partridge, Alastair Thompson. Emerging from COVID-19 pandemic: Provider perspective on use of neoadjuvant endocrine therapy (NET) in early stage hormone receptor positive breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SS2-05.