Guideline: Expert guidelines on COVID-19 vaccines and timing of breast screening tests

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At a glance What does this mean for me?
In the news Guidelines
Vaccines, lymph nodes and screening Questions for your doctor
When should you have screening? Resources and reference



What is this news about?

In response to news media reports of swollen lymph nodes being seen on mammograms following COVID-19 vaccinations, the Society for Breast Imaging released recommendations regarding the best timing for mammograms after having a COVID-19 vaccination.


Why is this news important?

Screening mammograms and COVID-19 vaccines are both important for your health. Because reports of swollen lymph nodes seen on mammography are increasing, a few professional societies have issued patient guidelines for when to schedule screening mammograms.  Guidelines have also been issued for healthcare providers regarding how to interpret swollen lymph nodes that are detected by mammography after vaccination for COVID-19.


In the news

Recent headlines on COVID-19 vaccinations and mammography, including the following examples, can be confusing and scary, while others do not tell the whole story:

  • “Mammograms pick up swelling due to COVID-19 vaccine, causing unnecessary fear, radiologists say.”
  •  “It can be alarming: COVID vaccine side effect may be mistaken as breast cancer.”
  • “COVID-19 vaccine: Should I reschedule my mammogram?”
  • “Why you should reschedule your mammogram if you recently got the COVID-19 vaccine.”
  • “Swollen lymph nodes, one COVID-19 vaccine side effect, could be misread as cancer, experts warn.”


COVID-19 vaccines, swollen lymph nodes and screening mammograms

Some people develop swollen lymph nodes following a COVID-19 vaccination. This a harmless and temporary response by the immune system to the vaccination. Swelling that develops in the underarm lymph nodes of the arm where the shot is given is a normal response to vaccination.  It is a sign that the vaccine is working and that the immune system is responding. This swelling usually disappears in a few days or weeks. 

If you have recently had a COVID-19 vaccination, mammography may detect swollen lymph nodes.  Rarely, swollen lymph nodes can be a sign of breast cancer. If swollen lymph nodes are seen on your mammogram, you may be encouraged to return to the breast center for an ultrasound of your underarm and/or have a follow-up exam to confirm that the lymph nodes have returned to their normal size.

Allison W. Kurian, MD, FORCE Advisory Board Director Emeritus, said,“I had substantial axillary lymph node swelling after my second dose of the Pfizer vaccine and I have been telling all my patients, so they won’t be worried. Glad you [FORCE XRAY] are getting the word out!"


When should you have screening mammograms?

Try to schedule your screening mammogram at least four weeks after your second dose of vaccine or before your first dose of COVID vaccine (Moderna or Pfizer-BioNTech vaccines). Swollen lymph nodes were not listed among the reported side effects in a briefing released by the Food and Drug Administration about the Johnson & Johnson Covid vaccine.

The following recommendations apply if you have already scheduled your mammogram and vaccine:

  • If you have a screening mammogram scheduled right after your first or second vaccine, try to reschedule it so that you have the screening before your first shot or 4 weeks after your second shot.
  • If you are overdue for a screening mammogram or cannot reschedule, keep your appointment for the COVID-19 vaccination.
  • If you have a mammogram after your COVID-19 vaccination, provide your screening technician with the following information:
    • the date of your vaccination
    • whether the vaccine was given in the left or right arm or thigh
    • whether your vaccination was your first or second dose

This important information will help the breast radiologist to better interpret your screening mammogram.      

The following is recommended if you have been diagnosed with breast cancer:

  • request that you be given the shot in the arm that is opposite the side on which your breast cancer was diagnosed or in your thigh.
  • follow your oncologist’s and/or radiologist’s recommendations, which may include additional imaging or biopsy, if you have swollen lymph nodes after your vaccination.

For more information see our XRAY Guideline: COVID vaccines for people with cancer here.


What does this mean for me?

Both breast screening mammograms and COVID-19 vaccines are very important for your health. Getting vaccinated is critical to stop the spread of COVID-19. Having regular screening mammograms helps save lives by detecting breast cancer as early as possible. If you are significantly overdue for a screening mammogram, it is important to schedule and keep your appointment even if you have recently been vaccinated. Ideally, schedule your screening mammogram to occur before vaccination or four weeks after your last dose of vaccination.

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posted 3/30/2021

This article is relevant for:

People considering screening mammography after getting a COVID-19 vaccine.

This article is also relevant for:

Healthy people with average cancer risk

People with a genetic mutation linked to cancer risk

People with a family history of cancer

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Questions to Ask Your Doctor

  • When should I have a screening mammogram if I have been vaccinated for COVID-19?
  • I have not yet been vaccinated for COVID-19; when should I schedule my screening mammogram?
  • I am experiencing swollen lymph nodes following my COVID-19 vaccination. What should I do?

Open Clinical Trials

Who covered this study?

Cancer Health

Enlarged lymph nodes after COVID-19 vaccine may be mistaken for cancer metastasis This article rates 4.0 out of 5 stars

Good Morning America

New warning about women getting mammograms after getting vaccine This article rates 3.0 out of 5 stars

How we rated the media

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