New advice issued to women about Covid-19 vaccinations and mammograms

Ahead of New Zealand’s roll-out of the Covid-19 vaccine, Breast Cancer Foundation NZ is urging Kiwi women not to delay their mammograms. This comes as reports out of the United States suggest a possible side effect of the vaccine may mimic breast cancer symptoms.

The Society of Breast Imaging, a US-based non-profit organisation, has cited data showing about 12-16% of patients receiving either Moderna or Pfizer vaccines developed swollen lymph nodes in the armpit or neck. This occurred within a week of vaccination and affected the same side as the arm that was injected. Swollen axillary (armpit) nodes can be seen on mammogram and be mistaken as a sign of breast cancer. Based on these findings, the US organisation is recommending women have their mammograms before receiving the first dose of the Covid-19 vaccine, or wait four to six weeks after their second dose.

However, Breast Cancer Foundation NZ says this information shouldn’t be cause for alarm as this is not a common side effect and the risks of delaying mammograms outweigh the benefits.

Dr Monica Saini, medical advisor to Breast Cancer Foundation NZ and director of Breast Institute NZ, said: “While women should be made aware of this side effect we don’t want them to fear either getting vaccinated or having a mammogram. If you develop an armpit lump shortly after vaccination and the lump is the same side as the arm that received the jab, this may be related. Swollen lymph nodes are a sign that the vaccine is working and creating the antibodies needed to fight the virus, and should resolve within two weeks. That said, it’s important not to ignore a lump or other changes, and let your GP know.

“Breast cancer is most treatable when it’s caught early, which is why regular screening is our best tool. Make sure you’re up-to-date with your mammograms and let your doctor or radiologist know if you’ve had the Covid-19 vaccine recently, and in which arm.”