Anyone getting a mammogram or other cancer checkup shortly after a COVID-19 vaccine should alert doctors to prevent false alarms from a side effect.
Do you get a mammogram or other cancer check-up shortly after COVID-19 vaccination? Be sure to tell your doctor about the shot to avoid false alarm about a temporary side effect.
This is the advice of cancer experts and radiologists. Sometimes the lymph nodes, especially in the armpit, swell after vaccinations. It is a normal immune system reaction, but it could be confused with cancer if it appears on a mammogram or other scan.
“We need to get the word out,” said Dr. Melissa Chen, a radiologist at MD Anderson Cancer Center in Houston, who recently had to reassure a frightened patient who requested cancer testing because of an enlarged lymph node.
A group of experts from three cancer centers – MD Anderson, Sloan Kettering Memorial in New York and Dana-Farber in Boston – published recommendations last week in the journal Radiology on how to manage complicated side-effect scans.
The main message: “This should not prevent patients from receiving the vaccine,” said Chen, one of the co-authors.
The lymph nodes are part of the immune system where white blood cells that fight infections gather, spots that are usually too small to feel. But they can swell during the disease and after other types of vaccines. And with the anticipated jump in COVID-19 vaccinations, doctors should “prepare to see large volumes” of imaging tests – including chest CT, PET scans and mammograms – that show swollen lymph nodes, according to similar recommendations in the Journal of the American College of Radiology this week.
The most commonly affected nodes are in the armpit and near the collarbone, on the same side as the vaccination, Chen said.
The Food and Drug Administration lists the swellings along with other injection-related reactions commonly reported in Pfizer and Moderna vaccine studies, though not for the Johnson & Johnson vaccine.
It is not clear how often this happens. The FDA found that 16% of participants in the Moderna study reported some underarm swelling after the second dose. But if the lymph nodes are only slightly enlarged, they can appear on a medical scan, without people noticing any swelling.
Consumer advice is still evolving. If experts agree: if you have recently been vaccinated, tell your radiologist before any scan. This will help them assess whether an enlarged lymph node is likely to be linked to the vaccine and can simply be monitored or whether it is worrisome enough for a biopsy or other test.
And try to schedule an upcoming screening or other cancer-related scan before vaccination, if possible, without losing your place in the vaccine line, the radiology panel said.
People with active cancer who are on one side of the body may choose vaccination on the other side to minimize confusion.
Do not delay urgent examinations, emphasize radiologists. But there are some misunderstandings about non-urgent scans. The radiology panel said it would consider scheduling purely routine screenings six weeks after vaccination. In contrast, the recommendations from Massachusetts General Hospital urge us to manage the side effect with good communication rather than delayed screening.
———
The Associated Press Department of Health and Science receives support from the Howard Hughes Medical Institute’s Department of Science Education. AP is solely responsible for all content.