R. P. McDougall1, Y. Shi2, J. R. Gabriel1, M. Serafini2, J. R. Robbins3, C. C. Hsu4, C. Morrison4, and L. Wang Jr4; 1University of Arizona, Tucson, AZ, 2University of Arizona Cancer Center, Tucson, AZ, 3University of Arizona, College of Medicine-Tucson, Department of Radiation Oncology, Tucson, AZ, 4University of Arizona - Department of Radiation Oncology, Tucson, AZ
Purpose/Objective(s):The COVID-19 epidemic has significantly changed radiation management trends in early breast cancer. An ASCO survey from over 1000 radiation oncologists from 54 different countries showed that around 40% of respondents shifted their practice toward ultra-hypofractionated regimens or even omission of radiation for eligible patients. Practice trends for breast cancer patients in the US during this time remained to be determined. Materials/
Methods: The National Cancer Database was queried to identify all patients with early stage breast cancer (patients with DCIS, T1N0, or T2N0) who underwent breast conserving surgery and adjuvant radiation. Based on accepted 5 or 10 fraction partial breast regimens and established 5 fraction whole breast regimens with up to a 5-fraction boost, ultra-hypofractionated (HF) radiation was categorized as 10 fractions or less and conventional fractionation (CF) was considered >10 fractions. Pre-COVID era was defined as 2015-2019 and the COVID pandemic was defined as 2020-2021. Chi-square and ANOVA tests were utilized for statistical analysis to compare the two groups. Results: A total of 528,553 patients met inclusion criteria with 358,673 treated pre-COVID and 179,880 treated during COVID. Pre-COVID 4.8% of patients received HF compared with 11.4% during the COVID pandemic (p<0.001). Patients 70 years and older represented a larger percentage of the cohort during COVID compared to the pre-COVID era (27.1% vs 24.3%, p<0.001), and they received HF at a higher rate during COVID than those younger than 70 (17.0% vs 9.4%, p<0.001). A similar percentage of patients were treated with HF across academic and community centers (5% vs 4.8%, p=0.011) pre-COVID. However during COVID a higher percentage of patients at community centers were treated with HF compared w/ academic centers (12.7% vs 10.1% p<0.001). Charlson-Deyo Comorbidity Index (CCI) was not significantly different between HF and CF in the pre-COVID cohort (4.8% CCI-0, 4.8% CCI-1, 5.1% CCI-2+, p=0.21), but significant differed during COVID (11.1% CCI-0, 11.9% CCI-1, 15.1% CCI-2+, p<0.001). Patients were more likely to received HF during COVID for DCIS and T1N0 tumors than they were for T2N0 tumors (10.8% vs 12.2% vs 4.8% p<0.001). White patients were more likely to receive HF in both time points (Pre-COVID: 5.1% vs 3.8% Black patients, p<0.001; and during COVID 11.8% vs 9.2% Black patients p<0.001). Conclusion: In patients with early breast cancer, there was a significant increase in the percentage of patients treated with HF during COVID, however the majority of patients continued to be treated with CF. Longer follow-up is needed post-COVID to see if these trends change over time.