Can the COVID-19 Vaccine Lead to a False-Positive Mammogram?

At the onset of the COVID-19 pandemic, many women were concerned about going into hospitals or medical settings to receive a mammogram, for fear they’d put themselves at risk of contracting the coronavirus. Medical experts now say, that was a double-edged sword, as they’re seeing that some delayed screenings led to delayed diagnoses of breast cancer, and poor health outcomes, which could have potentially been avoided with a simple breast cancer screening.

As the pandemic winds down, more and more concerned women are asking whether or not the COVID-19 vaccine can somehow lead to a false-positive mammogram.

According to the American Cancer Society, the COVID-19 vaccine can, in fact, lead to a false-positive mammogram. The reason is that the COVID-19 vaccine can cause swollen lymph nodes in the armpit on the side where the injection was received, which is the body’s natural response. It’s important to note, this is evidence that your body’s immune system is doing what it is supposed to do -- make antibodies and train other cells to protect you. Those enlarged lymph nodes, however, can result in a false-positive mammogram. The enlarged lymph nodes caused by the body’s response to the COVID-19 vaccine can last anywhere from four to six weeks after vaccination and is only temporary.

The vaccine can, in fact, lead to abnormal findings, or a "false-positive," mammogram. This is not an abnormal finding in your breast tissue, but evidence of the lymph node enlargement from your vaccine.

According to the American Cancer Society, women forty years old, who are at average risk for breast cancer, should get a mammogram annually, as early detection is key to survival.

Experts recommend that anyone due for a routine breast cancer screening, who is also concerned about a “false alarm” consider scheduling it before you get vaccinated, or at least four to six weeks after your final dose. This short delay will not impact cancer incidence or survival rate.

For anyone who is at higher risk, and/or is experiencing new symptoms such as a breast lump, a mammogram should not be delayed. This population should schedule their mammogram immediately, even if it’s right after they’ve received their vaccine.

At Women & Infants Hospital we offer, in addition to standard screening and diagnostic mammograms, the latest breast mammography technology called digital breast tomosynthesis. This technology gives radiologists a three-dimensional (3D) look at breast tissue, versus the traditional two-dimensional images, giving medical experts a clearer and more comprehensive view. The result is a 15 percent increase in early detection of breast cancer and a reduction in false positives. 

With the pandemic winding down, women are being encouraged to no longer put off scheduling their annual mammograms.

As the population increases its daily vaccination rate, there’s no more room for excuses for delaying your mammogram, which could save your life!