The foremost network of cancer centers in the United States is recommending that people wait to get certain imaging such as mammograms until four to six weeks after their final dose of their coronavirus vaccine—as long as the delay does not interfere with their healthcare. The new guideline from the National Comprehensive Cancer Network (NCCN), of which the Rogel Cancer Center is a member, stems from a potential side effect of the COVID-19 vaccines: swollen lymph nodes.
“We have started to see swollen lymph nodes on a small fraction of imaging tests that involve the armpit, including mammograms,” says Kimberly Garver, MD, a clinical assistant professor in the department of radiology and the director of breast imaging at Michigan Medicine.
Temporary swelling of the lymph nodes is a normal side effect of various vaccines that can indicate the body is producing the necessary antibodies to defend itself against a virus. When swollen lymph nodes show up on mammograms, though, they can be considered signs of infection, inflammation, or cancer. Swollen lymph nodes were reported as an occasional reaction for only the Moderna and Pfizer-BioNTech vaccines, but the NCCN recommends that those who have received the Johnson & Johnson vaccine delay their imaging, too, since data is still emerging.
However, people should only postpone mammograms if this does not have a negative impact on their health, and Garver stresses that routine cancer screening is crucial to detect early disease. (Cancer screenings that do not involve imaging, like Pap and prostate tests, do not need to be delayed.
She recognizes that many people have already put off testing because of the pandemic and may have trouble finding another day they can take time off of work to come in for scans. To help people figure out when to get their screening mammogram in relation to their COVID vaccination, they should follow the guide below:
Tips for Timing COVID Vaccination and Breast Cancer Screening
- If patients have been vaccinated in the last six weeks, already have a mammogram scheduled to screen for cancer, and decide not to delay their test: If swollen lymph nodes show up on their scans, they may be called back for an additional mammogram and/or ultrasound of their armpit area. Speaking with their provider is essential to getting the best care based on their individual needs.
- If patients have not gotten a COVID vaccine yet and are due to undergo a mammogram in the near future: They should see if they can schedule their screening soon, before they get the COVID-19 vaccine. If a vaccination appointment becomes available and creates a conflict, they can always reschedule.