Regional lymphadenopathy following COVID-19 vaccination: Literature review and considerations for patient management in breast cancer care.

Abstract Purpose Over 1 billion doses of COVID-19 vaccines have been already administered across the United States, the United Kingdom and the European Union at the time of writing. Furthermore, 1.82 million booster doses have been administered in the US since 13th August, and similar booster programmes are currently planned or under consideration in the UK and the EU beginning in the autumn of 2021. Early reports showed an association between vaccine administration and the development of ipsilateral axillary and supraclavicular lymphadenopathy, which could interfere with the diagnosis, treatment and follow-up of breast cancer patients. In this paper, we review the available evidence on vaccine-related lymphadenopathy, and we discuss the clinical implications of the same on breast cancer diagnosis and management. Methods A literature search was performed – PubMed, Ovid Medline, Scopus, CINHAL, Springer Nature, ScienceDirect, Academic Search Premier and the Directory of Open Access Journals were searched for articles reporting on regional palpable or image-detected lymphadenopathy following COVID-19 vaccination. Separately, we compiled a series of case studies from the University Hospitals of Derby and Burton, United Kingdom and the Mayo Clinic in Minnesota, United States of America, to illustrate the impact that regional lymphadenopathy post-COVID-19 vaccination can have on the diagnosis and management of patients being seen in diagnostic and therapeutic breast clinics. Results From the literature search, 15 studies met the inclusion criteria (n = 2057 patients, 737 with lymphadenopathy). The incidence of lymphadenopathy ranged between 14.5% and 53% and persisted for >6 weeks in 29% of patients. Conclusions Clinicians managing breast cancer patients should be aware that the COVID-19 vaccination may result in regional lymphadenopathy in a significant number of patients, which can result in unnecessary investigations, treatment and increased patient anxiety. An accurate COVID-19 vaccination history should be collected from all patients where regional lymphadenopathy is a clinical and/or an imaging finding and then combined with clinical judgement when managing individual cases.