Abstract
PURPOSE: This study evaluates the effect of pandemic-related diagnostic and treatment delays on 3-year disease-free survival (DFS) in Taiwanese breast cancer patients. MATERIAL AND METHODS: This single-institution study analyzed breast cancer patients across three distinct periods: non-COVID-19 in 2017, pre-COVID-19 in 2019, and during the COVID-19 pandemic in 2020, to investigate the impact of the COVID-19 pandemic on DFS rates and recurrence rates. DFS was defined as the interval from surgery to the occurrence of breast cancer recurrence or death, whereas overall survival (OS) was defined as the interval from surgery to death from any cause. Follow-up protocol included regular clinical examinations and annual imaging, with a minimum follow-up of 36 months unless an event occurred earlier. RESULTS: The demographics of breast cancer patients changed from 2017 to 2020, with an average age increasing from 54.6 to 58.6 years. While overall survival (OS) did not vary significantly across the cohorts, DFS differed significantly, with the 2020 cohort experiencing a significant decline in DFS compared to 2017 (p = 0.027). Recurrence rates also increased, from 3.1% in 2017 to 7.6% in 2020. CONCLUSION: The COVID-19 pandemic had a negative impact on the DFS of breast cancer patients, with the 2020 cohort experiencing a significantly shorter DFS time compared to the 2017 cohort.