Study protocol: Impact of COVID-19 on Breast Cancer Patients and Services in a UK region: protocol for a mixed methods study.

BackgroundGlobally, breast cancer screening, diagnosis and treatment services were significantlyimpacted by the COVID-19 pandemic. Locally, the Northern Ireland Cancer Registry(NICR) reported an 11% reduction in breast cancers diagnosed April-December 2020compared with the same period 2018−2019 despite an expected increase. This studyaims to identify how the patient journey was impacted by the COVID-19 pandemicand how service provision can be improved.MethodsPopulation-based quantitative data will be collected by NICR for individuals diagnosed with invasive breast cancer (ICD 10 code C50). Data on presentation, investigations, comorbidities (including COVID-19 infection), molecular markers, stage atdiagnosis, treatment, and survival will be examined. Two time periods will be compared: March-December 2018 (pre-COVID-19 cohort) and March-December 2020(COVID-19 cohort). Analysis will include descriptive statistics, chi-square tests andANOVAs. Patient experiences of living with breast cancer and interacting with thehealthcare system during the pandemic (March 2020-April 2024) will be capturedthrough an online, self-completed, anonymous cross-sectional international survey.Quality of life will be captured in the survey using the EQ-5D-3L. Detailed descriptivequalitative interviews will be undertaken to better understand the lived experienceof breast cancer and recommend ways that services and support programs canPLOS One | https://doi.org/10.1371/journal.pone.0333288 September 29, 2025 2 / 9effectively meet the needs of this patient group. This study benefits from the inclusionof patient representatives who have been involved since the inception of this project.DiscussionThis study aims to quantify the impact of the COVID-19 pandemic on breast cancerpatient outcomes in a UK region and make recommendations to improve patient careand outcomes in the short and long term.