Q&A: Should COVID vaccinated patients delay getting breast imaging — new study says no 

In the weeks after the first COVID-19 vaccines were introduced in early 2021, it was quickly discovered the COVID vaccine can cause swollen lymph nodes that could mimic cancer on mammograms. To avoid needless biopsies of this vaccine-caused axillary adenopathy, women were told to hold off several weeks before getting breast imaging after they were vaccinated. However, a new study recently published in Radiological Society of North America (RSNA) journal Radiology now suggests that women might want to consider going through a screening regardless of when they were vaccinated.

In the study, "Axillary Adenopathy after COVID-19 Vaccine: No Reason to Delay Screening Mammogram," published online Feb. 8, 2022, researchers conducted a retrospective analysis of patients who received their vaccination and had breast imaging in the first few months of 2021. The study included more than 1,200 individuals imaged across 17 New York University (NYU) sites. Of those, about 44% (or 537 patients) experienced lymphadenopathy on at least one exam. Providers identified swelling on mammography alone in 9% of cases, ultrasound alone in 61% and on both modalities at a 30% rate. 

O the 8% of patients who underwent a biopsy, 79% were benign, while 21% had malignant results. Four patients were diagnosed with metastatic breast cancer and four patients were diagnosed with lymphoma. One patient with a known history of lung cancer was diagnosed with lung cancer metastatic to an axillary lymph node.

For this reason, the authors said delaying breast imaging in the COVID vaccination era should be reconsidered. 

The lead authors of the study were Stacey Wolfson, MD, chief resident, and Beatriu Reig, MD, MPH, clinical assistant professor of radiology, both from the Department of Radiology, NYU Grossman School of Medicine. Below they share additional details from the study and its key takeaway.

Can you give an overview of the study?

Stacy Wolfson: Prior recommendations included delaying mammograms for about 4-6 weeks after receiving the COVID-19 vaccine. So our study is now the largest, most comprehensive dataset evaluating the effects of these vaccines and what we see on breast imaging thereafter. What we are seeing is a lot of patients are having this lymphadenopathy, or the swollen lymph nodes, on the same side of of the body where they received the vaccine. W were able to kind of track that and see how many people have had it and what the time to resolution is.

There were 1,200 patients in this study who had breast imaging and had also received the COVID vaccine during the study timeframe.

What we saw from our study is that it's very common — about 44% of the women that had breast imaging during this time period after receiving the vaccine had lymphadenopathy. And the time to actual resolution of this lymphadenopathy is pretty variable, with some patients having an extended period of time to resolution, including some patients experiencing this lymphadenopathy as long as 43 weeks after the vaccine. And because of that and our extensive information that we've gathered, we're seeing that this time to resolution is variable and it is common to have these swollen lymph nodes. So we are saying that maybe it's not recommended to actually wait during this time prior to getting your breast imaging after getting the vaccine.

What does the study mean? Should breast imaging centers just tell all patients to come in and the radiologists will know there will likely be swelling of the lymph nodes near where they got vaccinated, and they will just take it into consideration when reading the exam?

Stacy Wolfson: So I think it's important to always take into consideration the patient context and the patient's individual risk factors. I think it's important to state to patients that we do know this benign reactive lymphadenopathy is very common. A lot of patients are experiencing it and the time to actual resolution is extended and is variable. So it's important to have that in the back of your mind when you're seeing this in a breast image, or even as a patient is experiencing this. But, it's also important to realize that some people don't fit this exact kind of criteria [with vaccine-caused adenopathy] and they might have elevated risk factors─ current history or prior history of cancer. That changes how we need to evaluate their imaging and their story.

But this should be used as a basis for the general population, because it is common to have this lymphadenopathy after COVID vaccinations, and the time to resolution is kind of variable. It's not necessary to wait after receiving the vaccine to just have your general screening. Because it is common, depending on your risk factors and what the clinician would see, that further imaging is not necessarily warranted. The time to resolution is variable and you might be following up on a benign lymph node for multiple follow up time periods waiting for this resolution. But we don't actually know when it would truly resolve.