COVID-19 vaccination and mammograms
Some recent articles in the media have drawn attention to emerging concerns about “false positive” results during mammography following COVID vaccination. The reports indicate that the vaccines cause a swelling of axillary lymph nodes (glands under the arms), which could be mistaken for breast cancer.
The concern is that the vaccine may cause swelling, which may then require imaging (such as mammography) and then may also lead to unnecessary biopsies. Avoiding unnecessary treatment, costs and the associated anxiety would be a good step.
Lymph node enlargement
Lymph node enlargement in the axillae can be seen in malignancies such as breast cancer, lung cancer and lymphomas. It can also be caused by a response to infection, as well as recent vaccination, usually in the corresponding arm.
Lymph node enlargement is also not unusual after vaccinations that evoke a strong immune response, such as the COVID-19 vaccine.
Scholarly articles so far are based on very few case descriptions of axillary lymph node enlargement after COVID-19 vaccination. One study referred to in some newspaper articles was based on a cohort of four patients.
A gold standard study tracking a cohort of 43,548 people receiving the Pfizer-BioNTech vaccine showed that lymph node swelling was reported in <0.1% of participants.
What if swelling is noticed?
Patients presenting to their GP with lymph node swelling following COVID-19 vaccination should be examined to rule out possible malignancy. Most will be followed-up in the short term, to check if it has resolved, before referring onward for imaging and potentially unnecessary biopsies.
When should I have the mammogram?
Although no official guidance on the topic has yet been published in the UK, it would be reasonable to opt for routine screening before receiving the COVID-19 vaccine, if possible.
Alternatively, deferring routine screening mammography to 4 weeks after the 2nd dose of vaccination, would enable imaging when most reactive lymph nodes have usually resolved.
Mammography saves lives
In the UK, the NHS offers breast screening to women over the age of 50 and it is recommended every 3 years. This is a longstanding screening programme proven to reduce the morbidity and mortality from breast cancer.
It is important to discuss with your doctor if you are unsure about when you should have your screening mammogram, rather than cancelling it altogether.
If you (or anyone you know) has any concerns about lumps in your breasts, or under the arms, regardless of whether you have recently had a COVID vaccination, you must speak to your GP.
Your doctor can examine you and refer you for imaging and specialist assessment if needed. Always ask for help at the earliest opportunity.
Dr. Sidra Malik BMBS MRCGP DRCOG DFSRH
17th February 2021