DEAR MAYO CLINIC: A friend of mine shared that she went for her annual mammogram last week. At the appointment, she was asked whether she had been vaccinated for COVID-19 and had experienced any changes in her breasts. I recently received my first dose of a COVID-19 vaccine. Although I feel fine, I'm wondering if there is a connection between being vaccinated for COVID-19 and increased risk for breast issues? I am due for my mammogram appointment in a few weeks.
ANSWER: In some women, breast cancer can present with lymph nodes that are swollen under one arm. Some patients have reported developing swollen lymph nodes after a COVID-19 vaccination, and this has raised questions about whether screening mammograms should be rescheduled due to concerns that this finding could be mistaken for a potential breast cancer diagnosis.
Mayo Clinic's recommendation is that women should not delay preventive screening. Regardless of whether you have been vaccinated for COVID-19, you should come in for your scheduled mammogram. You should let your mammography technologist know that you've been vaccinated for COVID-19, as well as how many doses you've received and which arm it was administered in. This information will be helpful in understanding the mammogram images.
In your specific situation, you may want to consider having your mammogram before your next dose of COVID-19 vaccine. If that is not possible, make sure you communicate with the technologist about your vaccination status.
Lymph nodes are part of your body's germ-fighting immune system. Your lymph nodes, also called lymph glands, play a vital role in your body's ability to fight off infections. They function as filters, trapping viruses and bacteria before they spread to other parts of the body. This is why swollen lymph nodes are common in many people when they are ill. Common areas where you might notice swollen lymph nodes include your neck, under your chin, in your armpits and in your groin.
When someone receives a vaccine, the lymph system is activated. Swollen lymph nodes are a common and harmless reaction to many vaccines, including vaccination for COVID-19. They typically occur under the arm where the shot was given. The swelling is a sign that your body is responding to the vaccine.
Depending on the amount of swelling, some people may notice their lymph nodes are larger, and these lymph nodes may feel tender or painful to the touch. The challenge is that when your health care team sees swollen lymph nodes on a mammogram, they will want to evaluate that further. With the reports of swollen lymph nodes related to COVID-19 vaccination, your health care team will want to be particularly vigilant, and make sure that swollen lymph nodes are related to COVID-19 vaccination and not breast cancer.
It is also important to note that swollen lymph nodes are not seen in every woman who has been vaccinated for COVID-19 and then has a mammogram. Most patients do not show changes in lymph node size on mammography.
For those patients who feel swollen lymph nodes in their underarm, the current standard would be to perform a mammogram and ultrasound of the area. If enlarged lymph nodes are seen on your mammogram, but you are asymptomatic, an ultrasound likely still will be recommended for further evaluation. You may be asked to return for a follow-up in three months for a repeat scan.
COVID-19 has put everyone on alert, but my advice to women in general is that if you cannot have your mammogram prior to being vaccinated for COVID-19, keep your already-scheduled mammogram appointment and advise the technologist about your vaccination. Encourage your family and friends to stay up to date with their preventive screenings, too. I also tell my patients that any skin changes ― swelling of the breast, new lumps or bumps, or nipple discharge ― should warrant an imaging workup. And that goes for women and men, since breast cancer can affect both sexes.
Early detection of breast cancer saves lives, so for that reason, regardless of what's happening in the world, it's important to not delay your breast cancer screening.
Patients with cancer are at an increased risk for developing severe illness from COVID-19, and being vaccinated for COVID-19 is one tool to help prevent infection. We are seeing guidelines that say women at any stage of breast cancer treatment should be vaccinated for COVID-19 if they're able. I encourage all cancer patients to be vaccinated for COVID-19 when it is available. But regardless of whether you are vaccinated for COVID-19, it is still important to practice safe behaviors, including wearing a mask in public, practicing social distancing and performing proper hand hygiene. ― Dr. Kristin Robinson, Radiology ― Diagnostic, Mayo Clinic, Jacksonville, Florida
Information in this post was accurate at the time of its posting. Due to the fluid nature of the COVID-19 pandemic, scientific understanding, along with guidelines and recommendations, may have changed since the original publication date.
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