Abstract P3-03-19: Incidence and time to resolution of axillary adenopathy on mammography after COVID-19 vaccination
Authors: Robinson Kristin , Maimone Santo , Advani Pooja P , Li Zhuo , Gococo-Benore Denise , Qosja Neda , Mummareddy Ashita , Ashai Ahmed M , Wilhelm Annamaria , Maxwell Robert , Wasserman Martha , Patel Neema , Morozov Andrey , Chumsri Saranya 
Published: March 2022

Background: This study reports incidence, timing, characteristics, and surveillance imaging of mammographic axillary adenopathy following COVID-19 vaccination. As COVID-19 immunizations continue, with possible booster vaccines upcoming, this study offers timing considerations and potential follow-up recommendations for breast imaging after vaccination. Methods: Retrospective analysis of patients (pts) who received at least one COVID-19 vaccine prior to screening (SM) or diagnostic mammography (DM) at Mayo Clinic Florida between January 15 to May 31, 2021. Vaccine-related information was queried by mammography technologists. Adenopathy was assessed by interpreting radiologists and follow-up studies were collated. Mammogram adenopathy included single enlarged node, multiple enlarged nodes, and adenopathy with soft tissue stranding. Ultrasound adenopathy included mildly prominent nodes with preserved fatty hila to rounded nodes with apparent loss of a fatty hilum. Wilcoxon rank-sum test and Fisher’s exact test were used to compare continuous and categorical variables, respectively. Multivariable logistic regression model was used to evaluate the association between days from vaccine and adenopathy. Results: Of 2349 pts, 34 (1.4%) had adenopathy (DM=6; SM=28) and 3 (0.1%) were symptomatic. Presence of axillary symptoms was associated with abnormal imaging (p&lt;0.001) with an odds ratio of 33 in multivariable model. Median time after vaccine for pts with adenopathy was significantly shorter at 14 days compared to 33 days for pts without adenopathy (p&lt;0.001). Incidence of adenopathy decreased as days from vaccine increased (3.4% for 0-14 days, 2.1% for 15-28 days, and 0.4% for &gt; 28 days, p&lt;0.001). After adjusting for being symptomatic, days from vaccine still had a significant impact on finding mammographic adenopathy (for each day after vaccine, OR=0.96, p&lt;0.001). No significant difference was seen based on age (p=0.66), vaccine brand (p=0.66), vaccine dose (p=0.18). ROC analysis to identify a cutoff value for presence/absence of adenopathy was 0.74 (95% CI 0.67-0.81) at 22.5 days following vaccination. Additional imaging with mammogram and/or ultrasound was requested for 31 pts. These included no follow-up (n=4, 12.9%), repeat ultrasound with or without mammogram in 1-3 months (n=26, 83.9%), and biopsy (n=1, 3.2%, pt with ipsilateral breast cancer with negative results, presumably vaccine induced). To date, all pts who underwent surveillance imaging demonstrated normalization of lymph node appearance. The median time for abnormal imaging related to adenopathy to return to BI-RADS 1 or 2 was 84 (range 13-157) days. Conclusion: The incidence of COVID-19 vaccine-induced adenopathy in this study (1.4%) appeared to be lower than self-reported axillary swelling in COVID-19 vaccine trials (16%) but is still higher than the reported incidence of adenopathy on an otherwise normal SM (0.02-0.04%). The incidence of adenopathy decreased significantly over time and was not present in most pts 28 days after the vaccine. In patients with abnormal adenopathy, followup imaging showed resolution of vaccine-induced adenopathy in most patients by 3 months.

Adenopathy(N=34)No Adenopathy (N=2315)P valueAge0.66N342314Median (Range)63.5 (35.0, 83.0)64.0 (30.0, 94.0)Q1, Q351.5, 72.555.0, 71.0Exam type&lt;0.001DM6 (13.3%)39 (86.7%)SM28 (1.2%)2276 (98.8%)Symptomatic&lt;0.001Missing032Yes3 (23.1%)10 (76.9%)No31 (1.3%)2273 (98.7%)Vaccine brand0.66Missing119mRNA-127319 (1.7%)1117 (98.3%)BNT162b214 (1.2%)1138 (98.8%)Other0 (0.0%)41 (100.0%)Vaccine dose0.18Missing0181st9 (2.2%)409 (97.8%)2nd25 (1.3%)1888 (98.7%)Days from vaccine&lt;0.001Median (Range)14.0 (1.0, 91.0)33.0 (0.0, 239.0)Q1, Q38.2, 20.816.0, 61.0Days from Vaccine&lt;0.0010-1418 (3.4%)519 (96.6%)15-2811 (2.1%)513 (97.9%)&gt;285 (0.4%)1283 (99.6%)

Citation Format: Kristin Robinson, Santo Maimone, Pooja P Advani, Zhuo Li, Denise Gococo-Benore, Neda Qosja, Ashita Mummareddy, Ahmed M Ashai, Annamaria Wilhelm, Robert Maxwell, Martha Wasserman, Neema Patel, Andrey Morozov, Saranya Chumsri. Incidence and time to resolution of axillary adenopathy on mammography after COVID-19 vaccination [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-03-19.