Findings from the LymphVAX study recently presented at the San Antonio Breast Cancer Symposium show that relatively
Lymph node swelling can be a particularly troubling side effect, since it could be mistaken for breast cancer progression. In this study, of 621 women who received the first dose of an mRNA COVID-19 vaccine, 9.8% developed lymph node swelling as compared with 12.9% of 621 women who received the second dose, and 11.3% of 469 women who received the third dose. The findings were comparable to those of studies conducted of the general population, said study author Brooke C. Juhel, BS, a clinical research coordinator in the lymphedema research program at Massachusetts General Hospital and a student at Harvard Medical School, both in Boston. In the general population, 10.2% experienced lymph node swelling after the first dose and 14% after the second dose, according to the Centers for Disease Control and studies of the Pfizer and Moderna vaccines.
“This is consistent with the hypothesis that, after repeated vaccine doses, the immune system already has the antigens ready to fight the virus, thus the side effects may worsen as the immune response has increased,” she said. “Having screened over 6,500 women for breast cancer–related lymphedema, and with our patients reaching out with concerns about vaccine side effects, we were in a unique position to conduct this study.”
The study also confirmed that the most common side effects of receiving mRNA COVID-19 vaccines for women treated for breast cancer included injection site soreness, fatigue, muscle soreness, headache and chills lasting an average of 48 hours, which are symptoms comparable with those experienced by the general population.
“The side-effect profiles reported in this study for a cohort of women treated for breast cancer can be used to provide evidence-based patient education regarding future COVID-19 vaccine administration. The effect of the COVID-19 vaccines on breast cancer–related lymphedema risk is currently unknown and more research is required. In the interim, we would recommend vaccination away from the side of lymph node removal, either in the contralateral arm or in the thigh,” Ms. Juhel said.
The median duration of lymph node swelling was less than 1 week. In cases where lymph node swelling occurred after the first dose, 54.1% had swelling in ipsilateral axillary lymph nodes, and 45.9% in contralateral axillary lymph nodes. About 29.5% experienced swelling in ipsilateral supraclavicular lymph nodes, and 18.0% in contralateral supraclavicular lymph nodes.
Injection-site soreness, fatigue, GMS, headache, and chills occurred less often among older individuals (P < .001), and fatigue, muscle soreness, headache, and chills occurred more frequently after the second dose than the first (P < .001). The median duration of all side effects was 48 hours or less.
“The informed education that can be produced based on these results will hopefully ease the fears of women treated for breast cancer and empower them to make informed decisions regarding future vaccine doses,” Ms. Juhel said.
Ms. Juhel has no relevant financial disclosures.