Delays In Operative Management Of Early-Stage, Estrogen-Receptor Positive Breast Cancer During The COVID-19 Pandemic - A Multi-institutional Matched Historical Cohort Study
*Élise Di Lena, *Brent Hopkins, *Stephanie M. Wong, Sarkis Meterissian
McGill University, Montreal, QC, Canada
Objectives: In March 2020, provincial guidelines recommended that breast cancer (BC) centers suspend non-emergent surgeries due to the COVID-19 pandemic, including delaying surgeries for estrogen-receptor positive (ER+) BCs with neoadjuvant endocrine therapy (NET). The objective of this study was to evaluate the oncologic outcomes of BC patients affected by these guidelines, specifically evaluating the risk of pathological upstaging.Methods:All female patients with stage I-II BC receiving NET during the COVID-19 pandemic at two referral-based academic BC centers were prospectively identified. Clinical and pathological data were collected. Patients were matched to a historical cohort of stage I-II ER+ BC patients treated with upfront surgery 35 days between 2010-2013. The primary outcomes were pathologic T and N upstaging compared to clinical staging at diagnosis and prior to NET initiation.Results:30 NET patients and 200 randomly selected historical patients were matched based on preoperative tumor grade and pathologic features. After matching, 29 NET patients and 53 upfront surgery patients remained. Median age in each group was 65 and 66, respectively (p=0.33). Most patients (79.3% and 81.1%) had invasive ductal carcinoma with a median clinical tumor size of 0.9 cm vs 1.7 cm (p = 0.005). Median time to surgery was 73 days in the NET group and 27 days in the upfront surgery group (p<0.001). 23 NET patients (82.2%) had the same or lower pT-stage compared to 36 (67.9%) upfront surgery patients (p = 0.308). Only 3 (10.3%) NET patients had an increase in pN-stage compared to 16 (30.2%) control patients (p = 0.056). Overall, 3 (10.3%) NET patients had a stage increase on final pathology versus 15 (28.3%) in the control group (p=0.158).Conclusion:Despite over 2.5 times longer delays to surgery, patients with ER+ BC receiving NET did not experience significantly different pathologic upstaging during the COVID-19 pandemic. These findings are limited by the small cohort size but support the use of NET in stage I-II ER+ BC if significant delays in surgery are projected.
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