Delays in operative management of early-stage, estrogen receptor–positive breast cancer during the COVID-19 pandemic: A multi-institutional matched historical cohort study

BACKGROUND: During the COVID-19 pandemic, guidelines recommended that breast cancer centers delay estrogen receptor–positive breast cancer surgeries with neoadjuvant endocrine therapy. We aimed to evaluate pathologic upstaging of breast cancer patients affected by these guidelines. METHODS: Female patients with stage I/II breast cancer receiving neoadjuvant endocrine therapy were prospectively identified and were matched to a historical cohort of stage I/II estrogen receptor–positive breast cancer patients treated with upfront surgery ≤35 days. Primary outcomes were pathologic T and N upstaging versus clinical staging. RESULTS: After matching, 28 neoadjuvant endocrine therapy and 48 control patients remained. Median age in each group was 65 (P = .68). Most patients (78.6% and 79.2%) had invasive ductal carcinoma with a clinical tumor size of 0.9 cm vs 1.7 cm (P = .056). Time to surgery was 68 days in the neoadjuvant endocrine therapy group and 26.5 days in the control (P < .001). A total of 23 neoadjuvant endocrine therapy patients (82.1%) had the same or lower pT-stage compared with 31 (64.5%) control patients (P = .115). Only 3 (10.7%) neoadjuvant endocrine therapy patients had increased pN-stage vs 14 (29.2%) control patients (P = .063). CONCLUSION: Despite 2.5-times longer delays, patients with early-stage estrogen receptor–positive breast cancer receiving neoadjuvant endocrine therapy did not experience pathologic upstaging during the COVID-19 pandemic. These findings may support the use of neoadjuvant endocrine therapy in similar patients if delays to surgery are projected.