Delays in Operative Management of Early-Stage, Estrogen-Receptor Positive Breast Cancer During the COVID-19 Pandemic – A Multi-Institutional Matched Historical Cohort Study

Di Lena, Élise; Hopkins, Brent; Wong, Stephanie M.; Meterissian, Sarkis

BACKGROUND: During the COVID-19 pandemic, guidelines recommended that breast cancer (BC) centers delay estrogen-receptor positive (ER+) BC surgeries with neoadjuvant endocrine therapy (NET). We aimed to evaluate pathological upstaging of BC patients affected by these guidelines. METHODS: Female patients with stage I-II BC receiving NET were prospectively identified and were matched to a historical cohort of stage I-II ER+ BC patients treated with upfront surgery ≤35 days. Primary outcomes were pathologic T- and N-upstaging vs clinical staging. RESULTS: After matching, 28 NET and 48 control patients remained. Median age in each group was 65 (p=0.68). Most patients (78.6% and 79.2%) had invasive ductal carcinoma with a clinical tumor size of 0.9cm vs 1.7cm (p=0.056). Time to surgery was 68 days in the NET group and 26.5 days in the control (p<0.001). 23 NET patients (82.1%) had the same or lower pT-stage compared to 31 (64.5%) control patients (p=0.115). Only 3 (10.7%) NET patients had increased pN-stage vs 14 (29.2%) control patients (p=0.063). CONCLUSION: Despite 2.5-times longer delays, patients with early-stage ER+ BC receiving NET did not experience pathologic upstaging during the COVID-19 pandemic. These findings may support the use of NET in similar patients if delays to surgery are projected.