DENVER (KDVR) — Swelling of the lymph nodes following COVID-19 inoculation is making breast cancer diagnosis a bit more challenging, according to physicians.

Scientists are still learning a lot about how the vaccines impact us in terms of side effects.

Mammograms are key to early detection of breast cancer. Radiologists are trained to look for some cancer warning signings that include swollen lymph nodes. For some people, the COVID-19 vaccines also make lymph nodes larger.

“So far, in the early observations, we think this is about 15% of women can have enlargement of their lymph nodes [following COVID-19 vaccination],” said Dr. Stephanie Miller.

Miller is a breast surgeon with HealthONE’s Rose Medical Center and North Suburban Medical Center. She said the COVID-19 vaccine lymph-node side effect is not unexpected. She stresses that the vaccine will not lead to breast cancer—just potential confusion in determining what is causing enlarged lymph nodes.

Miller said patients may try scheduling mammograms before being inoculated, if possible. They may also delay their mammogram by about four to six weeks after completing the vaccine schedule. However, Miller worries any delay could further complicate people’s busy schedules and lead to patients not getting their mammograms as often as they should.

Follow-up examination might be necessary for vaccinated individuals who have enlarged lymph nodes during a mammogram.