Abstract P1-12-04: Side Effects of the mRNA COVID-19 Vaccines in Women Treated for Breast Cancer
Authors: Juhel Brooke , Brunelle Cheryl L. , Bernstein Madison C. , Smith Louisa H. , Jung Amanda W. , Hausman Elizabeth K. , Bucci Loryn K. , Naoum George E. , Taghian Alphonse G. 
Published: March 2023

Abstract
Background: The introduction of the novel COVID-19 vaccination raised concerns regarding side effects from patients who had undergone breast cancer treatment. Lymph node swelling after the mRNA vaccines (Moderna, Pfizer) is a distressing side effect for women treated for breast cancer as it may indicate cancer progression or recurrence. Patients at risk of breast cancer-related lymphedema (BCRL) are fearful that lymph node swelling from the vaccine could incite or worsen BCRL. Data investigating associated side effects in this population is essential for patient education and future self-advocacy.
Purpose: The purpose of this study was to elicit side effects associated with the COVID vaccine in women treated for breast cancer.
Methods: 4,945 surveys were sent to women over the age of 18 who had received breast cancer treatment and had been prospectively screened for BCRL with perometry. 621 participants who received an mRNA vaccine and responded to the survey were included in analysis, 469 of whom completed booster dose surveys. Participants were asked about type and duration of side effects after each vaccine dose. Solicited side effects included injection site soreness, swelling, or redness; swelling, numbness, or heaviness of the arm; generalized muscle soreness (GMS); fatigue; headache; joint pain; chills; nausea; vomiting; fever; Bell’s palsy; axillary or supraclavicular lymph node swelling; other; or none of the above. We computed frequencies and the median duration of side effects for each dose. To investigate predictors of side effects, we fit multivariable logistic regression models separately for each side effect, with random effects for participants to account for clustered responses. We considered significant predictors those with p &lt; 0.05.
Results: Of the 621 participants, the median follow-up time between breast surgery and date of first vaccine dose was 69 months. The distribution of the top 5 side effects is presented in Table 1. Of note, the majority of participants who reported lymph node swelling (9.8% dose 1, 12.9% dose 2, 11.3% dose 3) reported it in the axilla ipsilateral to the vaccine (54.1% D1, 61.3% D2, 71.7% D3). Lymph node swelling was also reported in the axilla contralateral to the vaccine (45.9% D1, 45% D2, 24.5% D3), supraclavicular region ipsilateral (29.5% D1, 26.3% D2, 32.1% D3) and contralateral (18% D1, 18.8% D2, 9.4% D3) to the vaccine. Older patients reported each side effect significantly less frequently. Those who had received neoadjuvant chemotherapy reported significantly more GMS and headache than those who did not. Those who had received regional lymph node radiation were less likely to report GMS, as were patients who had sentinel lymph node biopsies (vs. no lymph node surgery). The median duration of side effects for all three doses was 48 hours or less, with the plurality (41.0% D1, 38.7% D2, 44.1% D3) of participants reporting side effects lasting 24 hours or less. While all side effects apart from injection site soreness were significantly more common in the second than the first doses, the duration of side effects only increased for 28.1% of participants.
Conclusion: Over 86% of women treated for breast cancer may experience at least one side effect after any dose of the COVID-19 vaccine. This data, collected specifically for patients with breast cancer, will help enhance guidelines for structured and universal education regarding additional doses of the vaccine in the future. This will allow patients to better understand COVID vaccine side effect profiles after breast cancer treatment and self-advocate prior to future doses.
Table 1. Top 5 Side Effects Reported
Citation Format: Brooke Juhel, Cheryl L. Brunelle, Madison C. Bernstein, Louisa H. Smith, Amanda W. Jung, Elizabeth K. Hausman, Loryn K. Bucci, George E. Naoum, Alphonse G. Taghian. Side Effects of the mRNA COVID-19 Vaccines in Women Treated for Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-12-04.